The Concept of Psychosis: Historical and Phenomenological Aspects
Einführung in die Phänomenologische Philosophie. Darmstadt, Germany ... Die Schizophrenie. In: Bumke O, editor. Handbuch der ...
The Concept of Psychosis: Historical and Phenomenological Aspects - PMC
 Back to Top
 [Skip to main content](#main-content)

![U.S. flag](https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/favicons/favicon-57.png)

An official website of the United States government

Here's how you know

![Dot gov](https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/icon-dot-gov.svg)

**The .gov means it’s official.**

Federal government websites often end in .gov or .mil. Before
sharing sensitive information, make sure you’re on a federal
government site.


![Https](https://www.ncbi.nlm.nih.gov/coreutils/uswds/img/icon-https.svg)

**The site is secure.**

The **https://** ensures that you are connecting to the
official website and that any information you provide is encrypted
and transmitted securely.


[![NIH NLM Logo](https://www.ncbi.nlm.nih.gov/coreutils/nwds/img/logos/AgencyLogo.svg)](https://www.ncbi.nlm.nih.gov/)

[Log in](https://account.ncbi.nlm.nih.gov)Show account info

Close

#### Account

Logged in as:

**username**

- [Dashboard](/myncbi/)
- [Publications](/myncbi/collections/bibliography/)
- [Account settings](/account/settings/)
- [Log out](/account/signout/)

[Access keys](https://www.ncbi.nlm.nih.gov/guide/browsers/#ncbi_accesskeys) [NCBI Homepage](https://www.ncbi.nlm.nih.gov) [MyNCBI Homepage](/myncbi/) [Main Content](#maincontent)Main Navigation

**Preview improvements coming to the PMC website in October 2024.**
**[Learn More](https://ncbiinsights.ncbi.nlm.nih.gov/2024/03/14/preview-pmc-improvements/) or**
**[Try it out now](https://pmc.ncbi.nlm.nih.gov/articles/PMC2632489/).**

[Home](/pmc/ "Home")

Search PMC Full-Text ArchiveSearch in PMC

- [Advanced Search](https://www.ncbi.nlm.nih.gov/pmc/advanced)
- [User Guide](/pmc/about/userguide/)

- [Journal List](/pmc/journals/)
- [Schizophr Bull](/pmc/journals/356/)
- [v.34(6); 2008 Nov](/pmc/issues/175959/)
- PMC2632489


###### Other Formats

- [PDF (114K)](/pmc/articles/PMC2632489/pdf/sbm136.pdf)

###### Actions

- Cite
- Collections





Add to Collections







- Create a new collection
- Add to an existing collection

Name your collection:


Name must be less than characters


Choose a collection:


Unable to load your collection due to an error

Please try again

Add

Cancel


###### Share

- Permalink




Copy


###### RESOURCES

- Similar articles


- Cited by other articles


- Links to NCBI Databases



- [Journal List](/pmc/journals/)
- [Schizophr Bull](/pmc/journals/356/)
- [v.34(6); 2008 Nov](/pmc/issues/175959/)
- PMC2632489


As a library, NLM provides access to scientific literature. Inclusion in an NLM database does not imply endorsement of, or agreement with,
the contents by NLM or the National Institutes of Health.

Learn more:
[PMC Disclaimer](/pmc/about/disclaimer/)
\|
[PMC Copyright Notice](/pmc/about/copyright/)

![Logo of schbul](/corehtml/pmc/pmcgifs/logo-schizobull.gif)

Schizophr Bull. 2008 Nov; 34(6): 1200–1210.

Published online 2008 Jan 3. doi: [10.1093/schbul/sbm136](//doi.org/10.1093%2Fschbul%2Fsbm136)

PMCID: PMC2632489

PMID: [18174608](https://pubmed.ncbi.nlm.nih.gov/18174608)

# The Concept of Psychosis: Historical and Phenomenological Aspects

[Martin Bürgy](https://pubmed.ncbi.nlm.nih.gov/?term=Bürgy%20M%5BAuthor%5D)![corresponding author](/corehtml/pmc/pmcgifs/corrauth.gif)

Author informationCopyright and License information [PMC Disclaimer](/pmc/about/disclaimer/)

Psychiatric Hospital, University of Heidelberg, Voßstraße 4, D-69115 Heidelberg, Germany

![corresponding author](/corehtml/pmc/pmcgifs/corrauth.gif)Corresponding author.

To whom correspondence should be addressed; tel: +49-6221-562749, fax: +49-6221-565998, e-mail: [ed.grebledieh-inu.dem@ygreub\_nitram](mailto:dev@null).

[Copyright](/pmc/about/copyright/) © The Author 2008. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oxfordjournals.org.

## Abstract

The historical development of the concept of psychosis and its increasing differentiation from the neuroses up to the modern classification systems, _Diagnostic and Statistical Manual of Mental Disorders_ and _International Statistical Classification of Diseases_, is initially presented. In portraying this development, the struggle surrounding the clinical relevance of concepts on the one hand and their reliability and validity on the other are reflected. Thus far, diagnostic reliability has primarily been improved by focusing on externally observable symptoms in connection with expression and behavior. The identification of disease-specific symptoms, however, is principally achieved through the differential description of subjective experience. How this experience is to be explored and assessed remains for the most part unclear. With reference to its founder Karl Jaspers, the phenomenological method is presented as the decisive instrument for the assessment of experience. It is shown that a return to the legacy of phenomenology and a reformulation of the long-standing question concerning the specific symptoms of the schizophrenic psychosis are currently in progress. The revival of historical knowledge and a focus on direct clinical phenomena continue to provide inspiration for further advancement in modern psychiatry.

**Keywords:** psychosis, neurosis, history, phenomenology, schizophrenia, specific symptoms

## Introduction

At the start of the 20th century, Jaspers introduced the phenomenological method to psychiatry and laid the foundations for the scientifically grounded diagnostics and nosology which have permeated modern classification systems. In Germany, the phenomenological line of research dominated up to the middle of the 1970s, before being displaced by a more biologically oriented psychiatry. Although considerable progress has been made over the last few decades with respect to the therapy of mental illnesses (in particular for psychoses) and insight into their biological underpinnings, research has continued to visibly reach the limits of its own nosological premises. _Diagnostic and Statistical Manual of Mental Disorders_ ( _DSM_) and _International Statistical Classification of Diseases_ ( _ICD_) have above all contributed to an improvement in the reliability of psychiatric diagnostics and helped to abolish the “Babylonian confusion of tongues” which had prevailed in the field. Nonetheless, guidelines based on disease-specific symptoms continue to be necessary for an adequate systematization of the wealth of neurological findings which range from molecular genetics to functional and spectroscopic imaging. While current diagnostics are modeled on symptoms relating to expression and behavior, the differentiated assessment and description of subjective experience has led to increasingly sophisticated and specific diagnostics over the course of history. The phenomenological method is the prerequisite for the assessment of pathologically modified experience. Through the incorporation of historical knowledge and continual clinical application, this method can potentially further refine and deepen diagnostics and clinical competence.[1](#bib1),[2](#bib2) It is hoped that the current call to reconsider the legacy of phenomenology will provide new momentum in psychopathological and biological research.[3](#bib3)–[6](#bib6)

The present article will trace the historical development of the concept of psychosis up to modern-day classification systems. In appreciation of the significance of the subjective experience in psychopathology and nosology, this will be followed by a description of Karl Jaspers' phenomenological method including the philosophical roots and the reception of the method. The article concludes with a kaleidoscope-like portrayal of the current significance of the method in the search for specific symptoms of schizophrenia in positive, negative, early, and core symptoms.

## The History of the Concept

### Origin and Attempts at Differentiation

In 1841, Canstatt[7](#bib7) introduced the concept of psychosis into the psychiatric literature, a concept which he used synonymously with the term _psychic neurosis_.[8](#bib8) While the concept of neurosis was initially used to refer to all diseases of the nervous system,[9](#bib9) Canstatt thus emphasized the psychic manifestation of a disease of the brain.[10](#bib10),[11](#bib11) For a considerable length of time, Feuchtersleben[12](#bib12) was credited with first employing the term psychosis in 1845. In using psychosis as a synonym for psychopathy, Feuchtersleben emphasized both the change in the entire personality and the interaction between physical and mental processes. It was not until 1891 that Koch[13](#bib13) narrowed down Feuchtersleben's broad conceptualization of psychopathy to the _psychopathic inferiorities_, which he considered to be equally subject to congenital and acquired influences and which were later termed _abnormal personalities_ by Schneider.[14](#bib14) Canstatt and Feuchtersleben viewed the etiology of psychoses as lying in a somatic weakness of the brain on the one hand and in a psychic vulnerability on the other. The precedence of an organic neurological basis, as formulated by Friedreich[15](#bib15) in 1836, explains the continued classification of psychoses as neuroses up to the end of the 19th century. Through the introduction of the concept of psychosis, however, psychic pathology became increasingly viewed as a discrete entity.

In the second half of the 19th century, the term psychosis was widely used, although it continued to be applied as a synonym for terms such as _mental disorder_, _mental illness_, and _insanity_. In 1859, Flemming[16](#bib16) took up the term and used it to refer to both mental disorders with identifiable organic findings and disorders of the soul which were assumed to have an organic cause. In 1877, Flemming[17](#bib17) increased his accentuation of psychic pathology rooted in the organic. To begin with, the nosological focus remained upon that which Möbius in 1875 referred to as endogenous psychoses and covered the spectrum of hysteria, melancholy, mania, and paranoia.[18](#bib18) It was exclusively in light of etiological aspects that Möbius[19](#bib19) distinguished between exogenous and endogenous psychoses in 1892. Möbius, Kraepelin, and Jaspers in his early years used the term _exogenous_ to characterize the causation of mental disease through any extraneous influence, whether somatic or psychic in nature. Between 1908 and 1918, with his concept of the _exogenous reaction types_, Bonhoeffer[20](#bib20),[21](#bib21) took the decisive step in defining the exogenous. In his principle of unspecificity, Bonhoeffer ascertained that a psychic syndrome is not specific to a particular physical illness, but rather that a multitude of different physical diseases lead to highly similar psychic syndromes. With Bumke's[22](#bib22) equation of exogenous and somatogenic in 1924, the term officially received the meaning which has remained valid up to the present day.[23](#bib23)

While Möbius ascribed endogenous psychoses to a hereditary-degenerative cause, Griesinger had already described mental illnesses as diseases of the brain back in 1845. At the same time, Griesinger pointed out that it was not yet possible to name specific anatomical causes or to reduce the experience of the affected individual to somatic causes.[24](#bib24) Since the work of Schneider, endogenous has been understood as meaning that while the somatic cause of a psychosis is not identifiable, it is strongly assumed to exist on the basis of the psychopathology on display.[25](#bib25) Kraepelin and Bleuler subdivided endogenous psychoses into manic-depressive and schizophrenic disorders based on the course of the disease.[26](#bib26),[27](#bib27) The term _schizoaffective psychosis_, introduced by Kasanin[28](#bib28) in 1933, reflects the acceptance of intermediary schizoaffective disorders, in which the symptoms of schizophrenia and affective disorders mingle. Selecting a narrow interpretation of schizophrenia which centers on negative symptoms, as in the case of Kraepelin and dementia praecox, results in an expansion of the schizoaffective spectrum, whereas a broad conception of schizophrenia, as adopted by Bleuler and Schneider, results in a narrowing of the schizoaffective spectrum.[29](#bib29) This touches upon the notion of a unitary psychosis, a concept which can be traced back to the German psychiatrist Zeller and the modified versions of which continue to be of clinical and conceptual relevance up to the present day.[30](#bib30) Unitary psychosis connotes an absence of psychopathologically ascertainable nosological entities and points rather to a wide variety of disease variations which merge in all directions. The idea of a unitary psychosis thus opposes the concept of natural nosological entities or multiple and distinguishable psychoses which show individual symptomatology, etiology, and course.[31](#bib31),[32](#bib32)

In conclusion, it can be maintained that somatogenesis is of primary interest in the case of the exogenous psychoses. Psychic pathology remains for the most part unspecific in the etiology of the psychosis and is therefore of little significance. In the case of endogenous psychoses, a somatic pathogenic process is not verifiable but increasingly focused upon beginning with Kraepelin and continuing through the successive Heidelberg school including Jaspers and Schneider.[26](#bib26),[33](#bib33) While Canstatt, Feuchtersleben, and Flemming's concept of psychosis emphasized the psychic manifestation of an organically based neurosis, psychic pathology now becomes a manifestation of somatic etiology. The concept of psychosis thus converges with the original meaning of the term neurosis.[34](#bib34)

### The Influence of the Concept of Neurosis

The change in meaning of the term psychosis further resulted from the changing concept of neurosis, the meaning of which was inverted through developments in the fields of neuropathology and psychoanalysis. It was initially progress in the field of neuropathology and the discovery of new somatic pathological causes of disease which in the second half of the 19th century led to an increasing constriction of the concept of neurosis to purely psychogenic disorders. It was the period in which, for example, _Binswanger's dementia_, _Pick's_ and _Alzheimer's disease_, _multiple sclerosis_, _neurosyphilis_, and _diseases of the thyroid gland_ were discovered and described. Expressions such as _vasomotoric_, _trophic_, _traumatic_, _epileptic_, or _tetanic neurosis_ visibly disappeared from neurological and internal specialist terminology. In Strümpell's Manual of Internal Medicine from 1887, the neuroses finally reverted to the definition of _a disease of the nervous system with no known anatomical basis_.[35](#bib35)

It was, however, discoveries made within psychoanalysis that were of decisive importance for the change in meaning of the term “neurosis.” Clinical investigations of hysteria carried out by the French neuropathologist Charcot from the 70s of the 19th century onward led, in the face of a manifold of hitherto inadequately differentiated symptoms, to the establishment of a distinct nosological entity. Although diagnoses were made on the basis of psychic symptoms, Charcot assumed a degenerative etiology in the form of a mental weakness. In contrast, Freud's psychoanalysis resulted from changing social and intellectual conditions which focused on the individual with his/her social involvement and biographical development as well as on the disorders ensuing from these factors.[36](#bib36) While he was inspired by Charcot's work in embarking upon his investigations of hysteria, Freud[37](#bib37) (1895) went on to delineate the significance of the individual biography and sexuality in the etiology of the hysterical neurosis. The change in meaning of the term neurosis was completed when, after the year 1924, Freud[38](#bib38) ceased using the term _narcissistic neurosis_ to refer to psychotic illnesses such as dementia praecox, paranoia, and melancholia. Since then, the term neurosis has focused upon psychic pathology and psychogenesis. An unresolved childhood conflict is restimulated by a specific trigger situation. The emerging symptoms are considered to be a symbolic expression of the unconscious intrapsychic conflict and a compromise between desire and defense.[39](#bib39)

### The Dichotomy of Neurosis and Psychosis

Jaspers[40](#bib40) summarized the above-described development in the first edition of his _General Psychopathology_ in 1913. The dichotomy of psychosis and nonpsychosis or neurosis went on to form the foundation of psychiatric nosology. While psychoses are always the result of somatic illnesses and are therefore a _process_, neuroses have psychological biographical causes and are therefore a _development_ on a continuum with health. The dichotomy of process and development was followed by a dichotomization of methods, natural scientific _causal explanation_ of psychoses on the one hand and _psychological comprehension_ of neuroses on the other. Psychoses are not comprehensible but only explainable. The strict separation of methods facilitated clear differential diagnosis. Within each of the 2 groups, only a differential typology was possible. Schneider[41](#bib41) later went on to extend this nosological dichotomy into a triadic system by more strongly distinguishing between an exogenous and an endogenous type.

With his conception, Jaspers enforced clear diagnostic distinction and demanded accountability with respect to the methods applied for the very first time in the history of psychiatry.[42](#bib42) This concept of differential diagnosis, which allowed a clear prescription of therapeutic measures, formed the basis of Jaspers' now almost obsolete hierarchical principle. This principle was described by Jaspers in the first edition of his _General Psychopathology_ in a chapter on the _Classification of Psychoses_: “Pathological symptoms are layered like an onion, with degenerative symptoms (primarily the psychopathies, but also Kraepelin's manic-depressive insanity) forming the outmost layer, moving inwards to the process symptoms (schizophrenias) and finally the innermost layers comprising organically based symptoms. The deepest layer reached in the course of examining an individual case is decisive. What initially appears to be a case of hysteria turns out to be multiple sclerosis, suspected neurasthenia is actually paralysis, melancholic depression a process.”[40](#bib40)(p267) Jaspers' approach profited in precision from the continued exchange of ideas with Schneider and was later extended beyond psychoses to incorporate the entire spectrum of psychiatric nosology in a chapter on _Diagnostic Scheme_.[43](#bib43)(p512) For Schneider,[41](#bib41) just as for Huber[44](#bib44) in the present day, it was the layer with the deepest biological roots in the successive layers, _psychopathic-neurotic_, _depressive-manic_, _schizophrenic_, and _psycho-organic_, that was of crucial importance for diagnosis and therapy. Current versions of the _DSM_ and _ICD_ classification systems continue to be modeled—both in their structure and their diagnostic exclusion criteria—on the nosological hierarchy proposed by Jaspers and Schneider, although they no longer propagate a hierarchization of diagnoses. An abstention from clinical weighting of individual diagnoses in the conception of comorbidity only appears to be possible; its significance is regained, at the latest, in the selection and weighing up of therapeutic approaches.

According to Baeyer,[45](#bib45) Schneider's successor as head of the Heidelberg University Psychiatric Clinic, the concept of the fundamental incomprehensibility of psychoses resulted in the very Jaspers' theorem which steered research onto a biological track and which led to the segregation of psychotherapy from German psychiatry. While in 1913 Jaspers still acknowledged the significance of psychoanalysis in comprehending and treating neuroses, he later increasingly criticized the over expansion of the concept of comprehension in the case of psychoses, as well as the speculative and ideological character of psychoanalytic theory development.[46](#bib46) Following the Second World War, independent psychosomatic clinics were thus established outside of psychiatry.[47](#bib47) According to the Heidelberg school and later Schneider, psychotic symptoms were a diagnostic indication of biological etiology.[41](#bib41),[48](#bib48),[49](#bib49)

### More Recent Developments

The dichotomy between neurosis and psychosis prevailed in nosological classification up to _Diagnostic and Statistical Manual of Mental Disorders, Second Edition_ ( _DSM-II_)[50](#bib50) and _International Statistical Classification of Diseases, ninth Revision_.[51](#bib51) This was, however, due less to the influence of Jaspers and Schneider than to the impact of psychodynamic influences on American psychiatry after the Second World War.[47](#bib47) Indeed, the diagnostic hiatus between neurosis and psychosis which had been established by Jaspers and Schneider disappeared in the face of the somewhat simply stated belief that psychoses represented a particularly grave form of neuroses and were to be seen as reactions.[52](#bib52),[53](#bib53) The concept of psychosis was broadly defined and targeted in _DSM-II_ above all the severity of functional impairment, for example, at work, in interpersonal relationships, or in caring for oneself. In the transition from _Diagnostic and Statistical Manual of Mental Disorders, First Edition_ [54](#bib54) to _DSM-II_, the concept of neurosis was employed in a more inflationary and what can be consequently seen as a more arbitrary manner. The formerly independent conversion and dissociative reactions were in _DSM-II_, for instance, subsumed under the heading of hysterical neurosis.

_Diagnostic and Statistical Manual of Mental Disorders, Third Edition_ ( _DSM-III_)[55](#bib55) emerged in 1980 as a result of attempts to validate various diagnoses on the basis of substantive research evidence and above all to increase reliability by replacing previous etiological premises with descriptively developed, standardized research criteria.[56](#bib56)–[58](#bib58) The concepts of psychosis and neurosis were almost completely discarded. In working on the _International Statistical Classification of Diseases, 10th Revision_ ( _ICD-10_) classification, Cooper[59](#bib59)(p22) remarked in 1989 that “the differentiation between psychosis and neurosis as a fundamental organizing principle has been abandoned.”

From this point onward, the noun _psychosis_ was limited to its adjectival form _psychotic_. In 1994, in _Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition_ ( _DSM-IV_),[60](#bib60) the chapter _Schizophrenia and Other Psychotic Disorders_ subsumed a number of disorders in which psychotic symptoms dominate. In addition, other disorders, such as delirium, dementia, and major depression, can be accompanied by psychotic symptoms. Psychotic refers primarily to symptoms such as delusion and hallucinations. In the case of _schizophrenia_, the _schizophreniform disorder_, the _schizoaffective disorder_, and the _brief psychotic disorder_, additional symptoms including disorganized thinking or catatonic behavior can occur. The diagnosis of schizophrenia is primarily made on the basis of disturbances of expression and observable behavior. A-criterion such as delusion (A1), hallucinations (A2), disorganized thinking (A3), disorganized/catatonic behavior (A4), and negative symptoms (A5) are not viewed as significant unless accompanied by occupational or social dysfunction. The B-criterion thus stipulates clear functional impairment. The focus on observable indications and limitations certainly increases agreement among investigators.[61](#bib61),[62](#bib62) Nonetheless, it remains unclear how the subjective experiences, including the psychotic experience, of the patient are to be explored and assessed by the investigator. It is the view of the author that a loss of validity is to be expected when the method used to assess subjective experience is not reflected upon, the diversity of experience is reduced to the criteria found in classification systems and the search for that which is common and specific to the symptoms is abandoned.[1](#bib1),[2](#bib2)

## The Phenomenological Method

### Philosophy and Psychopathology

Phenomenology is the exploration and doctrine of the essence of that which manifests itself (Greek: _phainomenon_). The etymological derivation of the term indicates that a focus on that which is immediately given is the foundation of philosophization and common to all phenomenological approaches.[63](#bib63) Philosophically systematic preoccupation with the term began with Hegel's[64](#bib64) _Phenomenology of Spirit_ in 1807. According to Hegel, the spirit takes shape through history and attains self-consciousness through the self-reflexivity of mankind. Disillusionment with respect to the scope of knowledge to be gained through speculative idealism and romantic metaphysics lead to a clear orientation of philosophy toward the research subjects of the successful empirical sciences. It was against this backdrop that Husserl[65](#bib65) founded phenomenology in 1901 claiming it to be a fundamental science. Heidegger[66](#bib66)(p27) later referred to this development in the history of philosophy as a return “to the things themselves.”

In line with Brentano's concept of intentionality, world for Husserl[67](#bib67)(p154) was always consciousness of world. In attempting to trace terms back to “the direct experience of things,” Husserl was not interested in investigating external things, but rather the appearance of things in the intentionally directed stream of consciousness. The investigation of immediate experience was performed using the _descriptive method_ which was developed by Husserl. The precedence of this method was articulated by Husserl in a personal conversation with Jaspers: “you do not need to know what it is, if you do it right.”[68](#bib68)(p327)

Husserl's descriptive method was applied in the area of psychopathology in 1912 by Jaspers[69](#bib69) and introduced into psychiatry as a _phenomenological field of research_.[70](#bib70)–[72](#bib72) While Jaspers also drew upon the philosophical concepts of Kant, Dilthey, Droysen, Spranger, and Weber, from which the dichotomies of form and content, explanation and understanding, and development and process originate,[73](#bib73),[74](#bib74) and although the historical roots of describing psychopathological phenomena can be traced far back into the 19th century,[75](#bib75) it was the phenomenological method that represented the primary instrument for investigating and describing the subjective experience of the patient. In light of a psychopathology which was previously dominated by Kraepelin's behavioral observations, the innovative strength of such an approach cannot be highly enough esteemed.[76](#bib76) Later developments in phenomenology, such as Husserl's insight into essences or constitutive phenomenology, received just as little acknowledgment from Jaspers as the introduction of life-world or existential-analytical approaches in psychopathology.[77](#bib77),[78](#bib78) In the time that followed, these approaches continued to be of secondary importance in both clinical practice and research.

### Fundamental Principles From Jaspers' General Psychopathology

Jaspers[40](#bib40) initially equated phenomenology with a _static understanding_ according to which the investigator focuses on the cross-section of contents of consciousness. This understanding aims to capture current subjective experience as descriptively as possible, to distinguish experiences as clearly as possible, and to express these experiences in unambiguous terms which are primarily extracted from the self-descriptions of the patient. First, phenomenological investigation targets immediate experience because increasing distance between the investigator and the object of consciousness results in decreasing validity of psychopathological insight. Psychiatric diagnoses are thus not based on the course of illness but—as later also applied to Schneider[41](#bib41)—on cross-sectional psychopathological features, eg, the presence of first-rank symptoms in the case of schizophrenia. Second, phenomenological investigation focuses on the form of experience, ie, the way in which a content is experienced, while the content itself is of secondary importance. This weighting carries clear consequences, for example, in the investigation of psychotic experience. While, for example, _DSM-IV_ checks for bizarre contents of consciousness in the case of the phenomenon of delusion, content for Jaspers and later for Gruhle[79](#bib79) and Schneider[41](#bib41) is nothing more than a vehicle for the phenomenological investigation and extremely difficult to assess in terms of validity. In examining delusion, it is therefore the “how” of experience which is of primary importance, ie, whether a content of consciousness, a notion (delusional idea), or perception (delusional perception) has become highly invested with significance for no apparent rational or emotional reason and whether the affected individual is unshakably convicted of its truth (even if only temporarily, as in the case of the delusional idea).

_Static understanding_ is followed by _genetic understanding_, which centers on the longitudinal section of subjective experience. According to Jaspers, genetic understanding is no longer phenomenology, but rather an _understanding psychology_. Understanding psychology attempts to trace the inner development of personality and to show how one mental state clearly emerges from another. Of primary significance are therefore the contents of experience, which are empathetically woven together to form the inner biography. Despite being of little diagnostic validity, genetic understanding aims to capture the biographic development which in itself presents a coherent whole; a development which in the case of psychoses, for example, can be interrupted by a _break in the patient's lifeline_.

For Jaspers, _rational understanding_—which, for example, attempts to delineate the logical coherency of a delusional system from an external position—and _hermeneutic understanding_—which attempts to forge structures of meaning by, for example, applying philosophy or historical experience in an interpretational manner to the case under study—continually decrease in diagnostic value. In 1959, in the final edition of _General Psychopathology_ edited by Jaspers,[43](#bib43) the complexity of phenomenological understanding was accounted for by drawing upon the _hermeneutic circle_. Phenomenological understanding begins with the placing of oneself in the mindset of the mentally ill patient in an as nonjudgmental and impartial a manner as possible and comprises communication and a joint grappling with psychopathological concepts. It circulates from individual contents of consciousness to the whole and from the whole back to the individual in order to continually include new behavioral observations. It is only through these complex circular motions that understanding gains its precision. Only then is it possible to individually weight the individual symptoms and their involvement in the entirety of experience and in the biographical development of the patient.

In the modest manner which was characteristic of Jaspers, he continued to reject the reference to his book as a “major work in the area of phenomenology”(p42) up to the very end and ascertained that “A satisfactory organization and classification of phenomenological entities is not yet possible. Phenomenology is one of the foundations of the entire field of psychopathology and is still in its early stages.”(p51)

### Problems With the Reception of Jaspers

In the very first review of _General Psychopathology_ back in 1914, Bumke[80](#bib80) had already recognized the significance of the book for the establishment of a scientific psychopathology and nosology. Schneider[81](#bib81) and Gruhle,[82](#bib82) however, soon pointed out the necessity of repeatedly reading the book in order to acquire a gradual understanding of the methods and concepts involved. The reception barrier in Germany grew from edition to edition, mainly due to the increasing influence of philosophy.[72](#bib72)

In the 1930s, Great Britain became a place of refuge for a series of continental European psychiatrists.[83](#bib83) Mayer-Gross, who emigrated from Heidelberg to London, was familiar with Jaspers' phenomenology and demanded of his staff and students that they precisely describe mental phenomena.[84](#bib84) It is therefore even more surprising that, despite Mayer-Gross' teaching activities, no trace of an influence of Jaspers is to be found. Berrios[52](#bib52),[85](#bib85) and Mullen[86](#bib86) suspect that, in addition to the German language barrier, the complexity of the concepts influenced by continental philosophy posed a central stumbling block. The initially psychoanalytical and increasingly empirical-biological direction taken in Anglo-Saxon psychiatry is almost certainly a further reason why _General Psychopathology_ first emerged in the English language as late as 1963[87](#bib87)—exactly 50 years after the first German edition.

In 1967, in the United States, Fish[88](#bib88) published his book _Clinical Psychopathology_, which was strongly modeled on Jaspers' phenomenological approach. While Fish thus helped to counteract what can be seen as a lack of meticulous symptom description in American literature, excessive philosophy continued to hinder the reception of _General Psychopathology_ even after translation.[89](#bib89) In 2004, Hoenig,[90](#bib90)(p235) who together with Hamilton carried out the English translation of Jaspers' work, reported on his personal experiences with the reception of the book in _The History of the English Translation_: “Once I visited one of the medical schools in Philadelphia, and when the chairman took me to his office I noticed the book on his shelf. I asked him whether he liked it. He said, half jokingly, ‘Nobody reads it, but it is obligatory to have it seen on your shelf.’ End of discussion. In the UK, too, not everyone welcomed the book. Once Professor Stengel, a leading psychoanalyst, took me aside and said: ‘Why do you waste your time with this ‘Imperial Psychiatry’?’”

## Phenomenology and Schizophrenic Psychosis

### Searching for Specific Symptoms in Schizophrenia

As early as 1896, Kraepelin had attempted to identify a specific symptom connecting the various forms of dementia praecox, a symptom for which he coined the term “Zerfahrenheit” (English: distraction, dilapidation, incoherence).[91](#bib91) Zerfahrenheit subsumes formal thought disorders for which the following descriptions can apply: getting confused, becoming blurred, losing grip, or a derailing of thought to the point of schizophasia. Kraepelin's patient descriptions are viewed as highly differentiated, although they focus more on manifest expression than subjective experience.[92](#bib92) Schneider later classified Zerfahrenheit as belonging to the diagnostically less conclusive _expression symptoms_, ie, disorders of mimic, gesture, gait, voice, and speech. In contrast to Kraepelin, Bleuler[93](#bib93) clearly came closer to the experience of the patient. His renowned distinction of primary symptoms as an expression of the suspected somatic illness from secondary symptoms as an expression of the biographically determined reaction to the onset of illness opened up a way for drawing near to the patient in an understanding manner. Of even greater significance was, however, Bleuler's distinction between fundamental and accessory symptoms according to diagnostic value. While accessory symptoms, which included delusion and hallucinations, were seen by Bleuler as temporary and unspecific, fundamental symptoms were viewed as representing a permanent modification of the entire personality. Common to all fundamental symptoms was a _loosening of the tension of associations_.

Subsequently, numerous attempts were undertaken to identify the specific _weakness_ or _insufficiency_ inductive of secondary symptoms.[94](#bib94) The majority of these attempts were made by German-speaking psychiatrists, who were closely connected with the Heidelberg Clinic and its phenomenological approach. The line of tradition stretches from Berze,[95](#bib95) Beringer,[96](#bib96) Berze and Gruhle,[97](#bib97) Gruhle,[79](#bib79) Rümke,[98](#bib98) Conrad,[99](#bib99) Blankenburg,[100](#bib100) Mundt,[101](#bib101) Janzarik,[102](#bib102) up to Gross and Huber,[103](#bib103) and Klosterkötter.[104](#bib104),[105](#bib105) Since the time of Kraepelin, the search for an integrative concept accounting for the diverse array of schizophrenic symptoms has been and remains one of the most central questions in psychopathological research.[106](#bib106)

### Positive and Negative Symptoms

Jaspers viewed the consideration of basic disorder concepts as useless because these expressed nothing more and nothing less than the _incomprehensibility_ of the psychotic.[43](#bib43)(p486,487) At the same time, phenomenological examination was to remain limited to the psychopathological cross-section, ie, static understanding from a methodological viewpoint. Schneider[41](#bib41) expressly pointed out that his cross-sectionally assessed first-rank symptoms were not identical to the basic disorder but rather represented a differential diagnostic appraisal in discriminating from the nonpsychotic and the cyclothymias. He restricted his descriptions to _abnormal forms of experience_ and _abnormal forms of expression_. For Schneider, externally observable symptoms of expression were of least diagnostic value. First- and second-rank symptoms were most significant in diagnosing schizophrenia. These were phenomenologically conceived of as abnormal experiences, which, however, did not necessarily have to be present or manifest in the course of illness.

The concept of first-rank symptoms was made internationally accessible through translation of the fifth edition of Clinical Psychopathology into English in 1959,[107](#bib107) through Fish's book[88](#bib88) and through the International Pilot Study of Schizophrenia carried out by the World Health Organization.[108](#bib108) The concept is widely accepted[109](#bib109)–[111](#bib111) as a component of the diagnostic criteria in _DSM-III_ and _ICD-10_.[112](#bib112) The diagnostic significance and specificity of the first-rank symptoms is, however, a subject of constant dispute, as a result of which new impetus for the continued development of diagnostic criteria is generated.[113](#bib113)–[115](#bib115)

Crow's[116](#bib116) simplifying description of schizophrenia in terms of a positive and a negative form has, for example, led to increased interest in pathological deficits. In distinguishing between primary and secondary negative symptoms, Carpenter et al[117](#bib117) have revived the long-standing question concerning primary core deficits. Andreasen[118](#bib118) calls for an investigation of the negative symptoms which were described by Kraepelin and Bleuler as schizophrenic core symptoms and which have thus far been neglected on account of concerns with respect to a lack of reliability. The focus of research has thus shifted toward patients with low positive and high negative symptoms, as striven for by Blankenburg[100](#bib100) in his phenomenological study back in 1971. For Andreasen and Carpenter[119](#bib119) and Andreasen,[120](#bib120) it is the thought disorders described by Bleuler which are of primary interest. As primary symptoms, these disorders indicate the presence of a _misconnection syndrome_ involving the cortico-cerebellar-thalamic-cortical circuit and also serve to supplement a group of schizophrenias primarily defined on the basis of first-rank symptoms.

### Early Schizophrenia

Within Anglo-Saxon psychiatry, the term phenomenology appears to primarily refer to the description of externally observable symptoms, so that even subjective consciousness and experience are treated as elements of the natural environment.[121](#bib121) In the early diagnosis of schizophrenia, the “Anglo-Saxon school” therefore assumes a _prodromal phase_ which begins with initial changes in the patient's behavior and ends with the onset of the first psychotic episode.[122](#bib122) On the basis of such unspecific early symptoms, an early prediction of schizophrenia is scarcely possible.[123](#bib123),[124](#bib124) In their review, Cannon et al[125](#bib125) report a predictive value of 30%–35% in an ultrahigh-risk group within a period of 1–2 years.

The so-called “German school” draws upon _basic deficits_,[122](#bib122) a concept which corresponds to the primary symptom approach. Basic symptoms are neuropsychological disturbances which are perceived by the patient him/herself and which can be explored with the aid of the phenomenological method.[126](#bib126),[127](#bib127) Klosterkötter[128](#bib128) delineated so-called transition sequences in the development from basic symptoms to manifest psychotic symptoms. In 1987, Gross et al[129](#bib129) pooled the early symptoms of schizophrenia in the _Bonn Scale for the Assessment of Basic Symptoms_. In the course of an 8-year follow-up investigation of 96 identified patients, first-rank symptoms occurred in 58%, although—with 23% false-positive diagnoses—room for improvement was evident with respect to specificity.[130](#bib130) The predictive value of the basic symptoms primarily rests on subjectively perceived, cognitive phenomena such as thought disorders or distortions of perception. Follow-up studies over a considerably shorter period of time which have focused more intensely on neurocognitive indicators and the distinction between early and later prodromal phase have failed to produce improvements in predictive value or sensitivity.[131](#bib131),[132](#bib132) The search for conclusive neurocognitive indicators continues at an international level.[133](#bib133),[134](#bib134)

### A New Phenomenological Approach to Core Symptoms

For some length of time, Parnas et al[135](#bib135) have been working on an interesting and promising approach to phenomenological diagnostics, which sees the core schizophrenic syndrome in a form of depersonalization. The historic roots of this approach are to be found in German-speaking psychiatry. (I have elsewhere attempted with the concept of _obsession in a stricter sense_ to elucidate the core syndrome of obsessive-compulsive disorder using the phenomenological method.[136](#bib136),[137](#bib137))

Jaspers[40](#bib40) proposed the following modes in which the self is aware of itself: (1) _activity of the self_, (2) _unity of the self_, (3) _continuity of self-identity over time_, and (4) _distinction of the self from the outside world_. Disturbance of one of these modes results in typical formal disorders of self-consciousness. Jaspers attributed particular importance to the activity of the self. This activity accompanies all thoughts, images, memories, feelings, and perceptions, including perceptions of the body, and lends these the quality of being _mine_, of being _personal_. Depersonalization represents formal variation of the activity of the self. In depersonalization, contents of consciousness are no longer mine, but rather alien. Schneider[41](#bib41) strengthened Jaspers' point of view by indicating that, in clinical practice, it is exclusively _consciousness of activity_—which he more precisely formulated as _sense of mineness_—that is disturbed. The _disturbance of mineness_ leads to formal incomprehensibility of the contents of consciousness.

In terms of diagnostic valuation, Jaspers equated depersonalization with the “Erlebnis des Gemachten,”(p90) ie, with the impression of being manipulated, influenced, or guided by an external source, and Schneider identified the disturbance of mineness with ipseity disturbance, which he viewed as including thought insertion and thought withdrawal. He combined ipseity disturbance with delusion and hallucinations to form the first-rank symptoms of schizophrenia. For the benefit of diagnostic clarity, potential transitions as well as the distinction between primary and secondary symptoms were abandoned. In his phenomenological approach from 1960, Kisker[138](#bib138) attributed a very different value to ipseity disturbance. He viewed thought insertion as a secondary symptom of a primary _autopsychic depersonalization_. The concept of ipseity disturbance is not established within _DSM_ classification.[2](#bib2) Thought insertion and withdrawal are classified under bizarre delusional phenomena, while depersonalization is not referred to as a primary symptom.[60](#bib60) In contrast, Blankenburg[100](#bib100) earlier listed _schizophrenic alienation_ as a specific primary symptom and Bleuler[139](#bib139) referred to _depersonalization_ as a fundamental symptom of schizophrenia. Bleuler described depersonalization in the form of transitivism, appersonation, and deficient orientation with respect to one's own person, as a result of which the boundaries of the self are perceived as being undefined, thinking and feeling become alien, and the environment is dependent upon one's own will. Furthermore, even delusion and hallucinations can be understood as an alienation from the contents of one's own consciousness.[140](#bib140)

In accordance with phenomenological tradition, Zahavi and Parnas[141](#bib141) explicitly focused on the conceptualization of activity of the self as a stream of consciousness which lends the contents of consciousness their I-like character. In this way, all experience occurs as self-experience in the first-person, through an implicit prereflexive self-centering which accompanies every experience. The core syndrome of schizophrenia, which is thought to be specific for the schizophrenic spectrum as well as for prodromal schizophrenia, is described by Parnas et al[142](#bib142) as a disturbance of the prereflexive formation of experience and more specifically as an impairment of the prereflexive self-awareness which is viewed as the nucleus of the vast array of patient self-portrayals. The result is alienation from one's own thoughts, experiences, and actions; from interpersonal interactions; and from one's own body as well as a loss of that which was previously self-evident, the acquirement of a third-person perspective and a hyperreflexivity.[140](#bib140) Based on these conceptual considerations, Parnas et al[143](#bib143) have developed the _Examination of Anomalous Self-Experience_ ( _EASE_), a symptom checklist for the semistructured phenomenological exploration of symptoms. The EASE focuses on anomalies of self-experience in 5 experiential areas: (1) cognition and stream of consciousness, (2) self-awareness and presence, (3) bodily experience, (4) demarcation/transitivism, and (5) existential reorientation. It is claimed that an experienced EASE investigator is able to clearly distinguish between the monozygotic and dizygotic twin of a schizophrenic patient on the basis of the phenomenological exploration of self-experience.[144](#bib144)

## Conclusions

The consideration of the concept of psychosis is a conflict-charged domain of dichotomies which continue to be highly relevant within psychiatric diagnostics and nosology: psychosis and neurosis, unitary psychosis and multiple psychoses, etiological and descriptive diagnostics, forms of expression and forms of experience, primary and secondary symptoms, explanation and understanding, form and content, biological and phenomenological methods, etc. Knowledge concerning historical concepts may help to increase our awareness of the wealth of experience which psychiatry has to offer above and beyond current _DSM_ and _ICD_ classification systems. Following a 30-year focus on the establishment of diagnostic reliability and a common language as well as on advancements in a biological psychiatry within psychiatric research, the long-standing question once again resurfaces in unmodified form: What is psychosis or schizophrenia? The path which must be traveled in order to answer this question does not so much wind its way through expression and behavior as through an investigation of subjective experience, an approach which has proven most fruitful in the past. Experience is the research subject of the phenomenological method, the application of which is anything other than self-evident. It is in direct clinical contact with the patient that the method takes shape, its value is shown, and in turn, that which is common and specific to the illness is revealed.

The core syndrome of schizophrenia can be described as a disorder of self-consciousness. In the view of the author, a revival of the phenomenological method can contribute to improving the quality of psychiatric diagnoses. Through such a revival, psychiatric diagnostics would be reconnected with an important part of their history and also rerooted in the relationship to the patient, in whose interest the psychiatrist is commissioned with the tasks of carrying out research and providing treatment.

## References

1\. Andreasen NC. DSM and the death of phenomenology in America: an example of unintended consequences. Schizophr Bull. 2007;33:108–112.\[ [PMC free article](/pmc/articles/PMC2632284/)\] \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17158191)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Bull&title=DSM+and+the+death+of+phenomenology+in+America:+an+example+of+unintended+consequences&author=NC+Andreasen&volume=33&publication_year=2007&pages=108-112&pmid=17158191&)\]

2\. Saß H, Zaudig M, Houben I, Wittchen HU. Einführung zur deutschen Ausgabe: zur situation der operationalisierten Diagnostik in der deutschsprachigen Psychiatrie. In: Saß H, Wittchen HU, Zaudig M, editors. Diagnostisches und Statistisches Manual Psychischer Störungen DSM-IV. Göttingen, Germany: Hogrefe; 1996. pp. IV–XXIV. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Diagnostisches+und+Statistisches+Manual+Psychischer+Störungen+DSM-IV&author=H+Saß&author=M+Zaudig&author=I+Houben&author=HU+Wittchen&publication_year=1996&)\]

3\. Akiskal HS. The necessity of integrating phenomenology and neurobiology in bipolar disorder. J Affect Disord. 2006;94:1.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=J+Affect+Disord&title=The+necessity+of+integrating+phenomenology+and+neurobiology+in+bipolar+disorder&author=HS+Akiskal&volume=94&publication_year=2006&pages=1&)\]

4\. Harland R, Morgan C, Hutchinson G. Phenomenology, science and the anthropology of the self: a new model for the aetiology of psychosis. Br J Psychiatry. 2004;185:361–362. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/15516541)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+J+Psychiatry&title=Phenomenology,+science+and+the+anthropology+of+the+self:+a+new+model+for+the+aetiology+of+psychosis&author=R+Harland&author=C+Morgan&author=G+Hutchinson&volume=185&publication_year=2004&pages=361-362&pmid=15516541&)\]

5\. Mullen PE. A modest proposal for another phenomenological approach to psychopathology. Schizophr Bull. 2007;33:113–121.\[ [PMC free article](/pmc/articles/PMC2632295/)\] \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17023563)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Bull&title=A+modest+proposal+for+another+phenomenological+approach+to+psychopathology&author=PE+Mullen&volume=33&publication_year=2007&pages=113-121&pmid=17023563&)\]

6\. Mundt C. Anomalous self-experience: a plea for phenomenology. Psychopathology. 2005;38:231–235. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/16179810)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychopathology&title=Anomalous+self-experience:+a+plea+for+phenomenology&author=C+Mundt&volume=38&publication_year=2005&pages=231-235&pmid=16179810&)\]

7\. Canstatt C. Handbuch der Medizinischen Klinik. Stuttgart, Germany: Enke; 1841. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handbuch+der+Medizinischen+Klinik&author=C+Canstatt&publication_year=1841&)\]

8\. Scharfetter C. Psychische Vulnerabilität—Canstatt 1841. Nervenarzt. 1987;58:527. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3309691)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Psychische+Vulnerabilität—Canstatt+1841&author=C+Scharfetter&volume=58&publication_year=1987&pages=527&pmid=3309691&)\]

9\. Knoff WF. A history of the concept of neurosis, with memoir of William Cullen. Am J Psychiatry. 1970;127:80–84. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/4913140)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Am+J+Psychiatry&title=A+history+of+the+concept+of+neurosis,+with+memoir+of+William+Cullen&author=WF+Knoff&volume=127&publication_year=1970&pages=80-84&pmid=4913140&)\]

10\. Janzarik W. Der Psychose-Begriff und die Qualität des Psychotischen. Nervenarzt. 2003;74:3–11. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/12596022)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Der+Psychose-Begriff+und+die+Qualität+des+Psychotischen&author=W+Janzarik&volume=74&publication_year=2003&pages=3-11&pmid=12596022&)\]

11\. Schmidt-Degenhard M. Disposition—Vulnerabilität—Verletzlichkeit. Nervenarzt. 1988;59:573–585. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3070408)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Disposition—Vulnerabilität—Verletzlichkeit&author=M+Schmidt-Degenhard&volume=59&publication_year=1988&pages=573-585&pmid=3070408&)\]

12\. Feuchtersleben E v. Lehrbuch der Ärztlichen Seelenkunde. Wien, Austria: Gerold; 1845. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Lehrbuch+der+Ärztlichen+Seelenkunde&author=E+v+Feuchtersleben&publication_year=1845&)\]

13\. Koch JLA. Die Psychopathischen Minderwertigkeiten. Ravensburg, Germany: Dorn; 1891. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Die+Psychopathischen+Minderwertigkeiten&author=JLA+Koch&publication_year=1891&)\]

14\. Schneider K. Die Psychopathischen Persönlichkeiten. 9th ed. Wien, Austria: Deuticke; 1950. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Die+Psychopathischen+Persönlichkeiten&author=K+Schneider&publication_year=1950&)\]

15\. Friedreich JB. Historisch-Kritische Darstellung der Theorien über das Wesen und den Sitz der Psychischen Krankheiten. Leipzig, Germany: Wigand; 1836. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Historisch-Kritische+Darstellung+der+Theorien+über+das+Wesen+und+den+Sitz+der+Psychischen+Krankheiten&author=JB+Friedreich&publication_year=1836&)\]

16\. Flemming CF. Pathologie und Therapie der Psychosen. Berlin, Germany: Hirschwald; 1859. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Pathologie+und+Therapie+der+Psychosen&author=CF+Flemming&publication_year=1859&)\]

17\. Flemming CF. Psychosen und Neurosen. Allg Z Psychiatr. 1877;33:860–866.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Allg+Z+Psychiatr&title=Psychosen+und+Neurosen&author=CF+Flemming&volume=33&publication_year=1877&pages=860-866&)\]

18\. Schmidt-Degenhard M. Endogen. In: Battegay R, Glatzel J, Pöldinger W, Rauchfleisch U, editors. Handwörterbuch der Psychiatrie. 2nd ed. Stuttgart, Germany: Enke; 1992. pp. 142–145. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handwörterbuch+der+Psychiatrie&author=M+Schmidt-Degenhard&publication_year=1992&)\]

19\. Möbius PJ. Über die Einteilung der Krankheiten. Neurologische Betrachtungen. Centralbibliothek Nervenheilkd Psychiatr. 1892;15:289–301.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Centralbibliothek+Nervenheilkd+Psychiatr&title=Über+die+Einteilung+der+Krankheiten.+Neurologische+Betrachtungen&author=PJ+Möbius&volume=15&publication_year=1892&pages=289-301&)\]

20\. Bonhoeffer K. Zur Frage der Klassifikation der symptomatischen Psychosen. Berl Klin Wochenschr. 1908;45:2257–2260.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Berl+Klin+Wochenschr&title=Zur+Frage+der+Klassifikation+der+symptomatischen+Psychosen&author=K+Bonhoeffer&volume=45&publication_year=1908&pages=2257-2260&)\]

21\. Bonhoeffer K. Die exogenen Reaktionstypen. Arch Psychiatr Nervenkr. 1917;58:50–70.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Psychiatr+Nervenkr&title=Die+exogenen+Reaktionstypen&author=K+Bonhoeffer&volume=58&publication_year=1917&pages=50-70&)\]

22\. Bumke O. Lehrbuch der Geisteskrankheiten. München, Germany: Bergmann; 1924. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Lehrbuch+der+Geisteskrankheiten&author=O+Bumke&publication_year=1924&)\]

23\. Schmidt-Degenhard M. Exogen. In: Battegay R, Glatzel J, Pöldinger W, Rauchfleisch U, editors. Handwörterbuch der Psychiatrie. 2nd ed. Stuttgart, Germany: Enke; 1992. pp. 182–185. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handwörterbuch+der+Psychiatrie&author=M+Schmidt-Degenhard&publication_year=1992&)\]

24\. Tölle R. Wilhelm Griesingers magna charta der Psychiatrie. Zur Rezeptions- und Wirkungsgeschichte. Fortschr Neurol Psychiatr. 2002;70:613–619. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/12410432)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Fortschr+Neurol+Psychiatr&title=Wilhelm+Griesingers+magna+charta+der+Psychiatrie.+Zur+Rezeptions-+und+Wirkungsgeschichte&author=R+Tölle&volume=70&publication_year=2002&pages=613-619&pmid=12410432&)\]

25\. Beer M. Psychosis: from mental disorder to disease concept. Hist Psychiatry. 1995;6:177–200. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/11639691)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Hist+Psychiatry&title=Psychosis:+from+mental+disorder+to+disease+concept&author=M+Beer&volume=6&publication_year=1995&pages=177-200&pmid=11639691&)\]

26\. Hoenig J. The concept of schizophrenia. Kraepelin-Bleuler-Schneider. Br J Psychiatry. 1983;142:547–556. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/6349735)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+J+Psychiatry&title=The+concept+of+schizophrenia.+Kraepelin-Bleuler-Schneider&author=J+Hoenig&volume=142&publication_year=1983&pages=547-556&pmid=6349735&)\]

27\. Hoff P. Emil Kraepelin und die Psychiatrie als Klinische Wissenschaft. Ein Beitrag zum Selbstverständnis Psychiatrischer Forschung. Berlin, Germany: Springer; 1994. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Emil+Kraepelin+und+die+Psychiatrie+als+Klinische+Wissenschaft.+Ein+Beitrag+zum+Selbstverständnis+Psychiatrischer+Forschung&author=P+Hoff&publication_year=1994&)\]

28\. Kasanin J. The acute schizoaffective psychoses. Am J Psychiatry. 1933;13:97–126. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8192190)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Am+J+Psychiatry&title=The+acute+schizoaffective+psychoses&author=J+Kasanin&volume=13&publication_year=1933&pages=97-126&)\]

29\. Janzarik W. Der schizoaffektive zwischenbereich und die lehre von den primären und sekundären seelenstörungen. Nervenarzt. 1980;51:272–279. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/7007898)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Der+schizoaffektive+zwischenbereich+und+die+lehre+von+den+primären+und+sekundären+seelenstörungen&author=W+Janzarik&volume=51&publication_year=1980&pages=272-279&pmid=7007898&)\]

30\. Beer M. Psychosis: a history of the concept. Compr Psychiatry. 1996;37:273–291. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8826692)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Compr+Psychiatry&title=Psychosis:+a+history+of+the+concept&author=M+Beer&volume=37&publication_year=1996&pages=273-291&pmid=8826692&)\]

31\. Berrios GE, Beer M. The notation of unitary psychosis: a conceptual history. Hist Psychiatry. 1994;5:13–36. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/11639278)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Hist+Psychiatry&title=The+notation+of+unitary+psychosis:+a+conceptual+history&author=GE+Berrios&author=M+Beer&volume=5&publication_year=1994&pages=13-36&pmid=11639278&)\]

32\. Schmidt-Degenhard M. Einheitspsychose—Begriff und Idee. In: Mundt C, Saß H, editors. Für und Wider die Einheitspsychose. Stuttgart, Germany: Thieme; 1992. pp. 1–11. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Für+und+Wider+die+Einheitspsychose&author=M+Schmidt-Degenhard&publication_year=1992&)\]

33\. Janzarik W. Jaspers, Kurt Schneider and the Heidelberg school of psychiatry. Hist Psychiatry. 1998;9:241–252. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/11620106)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Hist+Psychiatry&title=Jaspers,+Kurt+Schneider+and+the+Heidelberg+school+of+psychiatry&author=W+Janzarik&volume=9&publication_year=1998&pages=241-252&pmid=11620106&)\]

34\. Beer M. The dichotomies: psychoses/neuroses and functional/organic: a historical perspective. Hist Psychiatry. 1996;7:231–255. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/11613409)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Hist+Psychiatry&title=The+dichotomies:+psychoses/neuroses+and+functional/organic:+a+historical+perspective&author=M+Beer&volume=7&publication_year=1996&pages=231-255&pmid=11613409&)\]

35\. Strümpell A. Lehrbuch der Speziellen Pathologie und Therapie der Inneren Krankheiten. 4th ed. Leipzig, Germany: Vogel; 1887. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Lehrbuch+der+Speziellen+Pathologie+und+Therapie+der+Inneren+Krankheiten&author=A+Strümpell&publication_year=1887&)\]

36\. Beer M. The importance of the social and intellectual contexts in a discussion of the history of the concept of psychosis. Psychol Med. 1995;25:317–321. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/7675919)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychol+Med&title=The+importance+of+the+social+and+intellectual+contexts+in+a+discussion+of+the+history+of+the+concept+of+psychosis&author=M+Beer&volume=25&publication_year=1995&pages=317-321&pmid=7675919&)\]

37\. Freud S, Breuer J. Studien zur Hysterie. Leipzig, Germany: Deuticke; 1895. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Studien+zur+Hysterie&author=S+Freud&author=J+Breuer&publication_year=1895&)\]

38\. Freud S. \[ [Google Scholar](https://scholar.google.com/scholar?q=Freud+S+)\]

39\. Laplanche J, Pontalis J-B. Das Vokabular der Psychoanalyse. Frankfurt, Germany: Suhrkamp; 1972. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Das+Vokabular+der+Psychoanalyse&author=J+Laplanche&author=J-B+Pontalis&publication_year=1972&)\]

40\. Jaspers K. Allgemeine Psychopathologie. Berlin, Germany: Springer; 1913. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Allgemeine+Psychopathologie&author=K+Jaspers&publication_year=1913&)\]

41\. Schneider K. Klinische Psychopathologie. 13th ed. Stuttgart, Germany: Thieme; 1987. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Klinische+Psychopathologie&author=K+Schneider&publication_year=1987&)\]

42\. Nassir Ghaemi S. Existence and pluralism: the rediscovery of Karl Jaspers. Psychopathology. 2007;40:75–82. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17215593)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychopathology&title=Existence+and+pluralism:+the+rediscovery+of+Karl+Jaspers&author=S+Nassir+Ghaemi&volume=40&publication_year=2007&pages=75-82&pmid=17215593&)\]

43\. Jaspers K. Allgemeine Psychopathologie. 7th ed. Berlin, Germany: Springer; 1959. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Allgemeine+Psychopathologie&author=K+Jaspers&publication_year=1959&)\]

44\. Huber G. Psychiatrie. Lehrbuch für Studium und Weiterbildung. 6th ed. Stuttgart, Germany: Schattauer; 1999. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Psychiatrie.+Lehrbuch+für+Studium+und+Weiterbildung&author=G+Huber&publication_year=1999&)\]

45\. Baeyer W v. Wähnen und Wahn. Stuttgart, Germany: Enke; 1979. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Wähnen+und+Wahn&author=W+v+Baeyer&publication_year=1979&)\]

46\. Jaspers K. Zur Kritik der psychoanalyse. Nervenarzt. 1950;21:465–468. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/14796780)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Zur+Kritik+der+psychoanalyse&author=K+Jaspers&volume=21&publication_year=1950&pages=465-468&pmid=14796780&)\]

47\. Ellenberger HF. The Discovery of the Unconscious. New York, NY: Basic Books; 1970. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=The+Discovery+of+the+Unconscious&author=HF+Ellenberger&publication_year=1970&)\]

48\. Bumke O. Handbuch der Geisteskrankheiten. Neunter Band, Spezieller Teil V; Die Schizophrenie. Berlin, Germany: Springer; 1932. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handbuch+der+Geisteskrankheiten.+Neunter+Band,+Spezieller+Teil+V;+Die+Schizophrenie&author=O+Bumke&publication_year=1932&)\]

49\. Janzarik W. Wandlungen des Schizophreniebegriffes. Nervenarzt. 1978;49:133–139. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/643128)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Wandlungen+des+Schizophreniebegriffes&author=W+Janzarik&volume=49&publication_year=1978&pages=133-139&pmid=643128&)\]

50\. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-II. Washington, DC: American Psychiatric Association; 1968. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Diagnostic+and+Statistical+Manual+of+Mental+Disorders:+DSM-II&publication_year=1968&)\]

51\. Degkwitz R, Helmchen H, Kockott G, Mombour W. Diagnosenschlüssel und Glossar Psychiatrischer Krankheiten: ICD-9. Berlin, Germany: Springer; 1980. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Diagnosenschlüssel+und+Glossar+Psychiatrischer+Krankheiten:+ICD-9&author=R+Degkwitz&author=H+Helmchen&author=G+Kockott&author=W+Mombour&publication_year=1980&)\]

52\. Berrios GE. The history of psychiatric concepts. In: Henn F, Satorius N, Helmchen H, Lauter H, editors. Contemporary Psychiatry, Vol 1, Part 2. Berlin, Germany: Springer; 2001. pp. 1–30. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Contemporary+Psychiatry,+Vol+1,+Part+2&author=GE+Berrios&publication_year=2001&)\]

53\. Warsitz RP. Psychose. In: Mertens W, Waldvogel B, editors. Handbuch Psychoanalytischer Grundbegriffe. Stuttgart, Germany: Kohlhammer; 2000. pp. 581–588. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handbuch+Psychoanalytischer+Grundbegriffe&author=RP+Warsitz&publication_year=2000&)\]

54\. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM. Washington, DC: American Psychiatric Association; 1952. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Diagnostic+and+Statistical+Manual+of+Mental+Disorders:+DSM&publication_year=1952&)\]

55\. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-III. Washington, DC: American Psychiatric Association; 1980. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Diagnostic+and+Statistical+Manual+of+Mental+Disorders:+DSM-III&publication_year=1980&)\]

56\. Bayer R, Spitzer RL. Neurosis, psychodynamics, and DSM-III. A history of the controversy. Arch Gen Psychiatry. 1985;42:187–196. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3883941)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=Neurosis,+psychodynamics,+and+DSM-III.+A+history+of+the+controversy&author=R+Bayer&author=RL+Spitzer&volume=42&publication_year=1985&pages=187-196&pmid=3883941&)\]

57\. Feighner JP, Robins E, Guze SB, Woodruff RA, Jr, Winokur G, Munoz R. Diagnostic criteria for use in psychiatric research. Arch Gen Psychiatry. 1972;26:57–63. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/5009428)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=Diagnostic+criteria+for+use+in+psychiatric+research&author=JP+Feighner&author=E+Robins&author=SB+Guze&author=RA+Woodruff&author=G+Winokur&volume=26&publication_year=1972&pages=57-63&pmid=5009428&)\]

58\. Spitzer RL, Endicott J, Robins E. Research diagnostic criteria: rationale and reliability. Arch Gen Psychiatry. 1978;35:773–782. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/655775)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=Research+diagnostic+criteria:+rationale+and+reliability&author=RL+Spitzer&author=J+Endicott&author=E+Robins&volume=35&publication_year=1978&pages=773-782&pmid=655775&)\]

59\. Cooper JE. An overview of the prospective ICD-10 classification of mental disorders. Br J Psychiatry. 1989;154(suppl):21–23. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/2605009)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+J+Psychiatry&title=An+overview+of+the+prospective+ICD-10+classification+of+mental+disorders&author=JE+Cooper&volume=154&issue=suppl&publication_year=1989&pages=21-23&)\]

60\. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders: DSM-IV. Washington, DC: American Psychiatric Association; 1994. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Diagnostic+and+Statistical+Manual+of+Mental+Disorders:+DSM-IV&publication_year=1994&)\]

61\. Endicott J, Nee J, Fleiss JL, Cohen J, Williams JB, Simon R. Diagnostic criteria for schizophrenia: reliabilities and agreement between systems. Arch Gen Psychiatry. 1982;39:884–889. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/7103677)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=Diagnostic+criteria+for+schizophrenia:+reliabilities+and+agreement+between+systems&author=J+Endicott&author=J+Nee&author=JL+Fleiss&author=J+Cohen&author=JB+Williams&volume=39&publication_year=1982&pages=884-889&pmid=7103677&)\]

62\. Satorius N, Ustun TB, Korten A, Cooper JE, van Drimmelen J. Progress towards achieving a common language in psychiatry, II: results from the international field trials of the ICD-10 diagnostic criteria for research for mental and behavioural disorders. Am J Psychiatry. 1995;152:1427–1437. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/7573580)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Am+J+Psychiatry&title=Progress+towards+achieving+a+common+language+in+psychiatry,+II:+results+from+the+international+field+trials+of+the+ICD-10+diagnostic+criteria+for+research+for+mental+and+behavioural+disorders&author=N+Satorius&author=TB+Ustun&author=A+Korten&author=JE+Cooper&author=J+van+Drimmelen&volume=152&publication_year=1995&pages=1427-1437&pmid=7573580&)\]

63\. Lembeck KH. Einführung in die Phänomenologische Philosophie. Darmstadt, Germany: wissenschaftliche Buchgesellschaft; 1994. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Einführung+in+die+Phänomenologische+Philosophie&author=KH+Lembeck&publication_year=1994&)\]

64\. Hegel GWF. Phänomenologie des Geistes, 1807. Hamburg, Germany: Meiner; 1988. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Phänomenologie+des+Geistes,+1807&author=GWF+Hegel&publication_year=1988&)\]

65\. Husserl E. Logische Untersuchungen. Halle, Germany: Niemeyer; 1901. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Logische+Untersuchungen&author=E+Husserl&publication_year=1901&)\]

66\. Heidegger M. Sein und Zeit (1927) Tübingen, Germany: Niemeyer; 1979. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Sein+und+Zeit+(1927)&author=M+Heidegger&publication_year=1979&)\]

67\. Husserl E. 1984. Logische Untersuchungen II. Untersuchungen zur Phänomenologie und Theorie der Erkenntnis (1919) \[ [Google Scholar](https://scholar.google.com/scholar?q=Husserl+E+Logische+Untersuchungen+II.+Untersuchungen+zur+Phänomenologie+und+Theorie+der+Erkenntnis+(1919)+1984+)\]

68\. Jaspers K. Rechenschaft und Ausblick. Reden und Aufsätze. München, Germany: Piper; 1951. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Rechenschaft+und+Ausblick.+Reden+und+Aufsätze&author=K+Jaspers&publication_year=1951&)\]

69\. Jaspers K. Die phänomenologische Forschungsrichtung in der Psychopathologie. Z Ges Neurol Psychiatr. 1912;9:391–408. Originally published, in English, The phenomenological approach in psychopathology in: Br J Psychiatry. 1968;114:1313–1323. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Z+Ges+Neurol+Psychiatr&title=Die+phänomenologische+Forschungsrichtung+in+der+Psychopathologie&author=K+Jaspers&volume=9&publication_year=1912&pages=391-408&)\]

70\. Langenbach M. Phenomenology, intentionality, and metal experiences: edmund Husserl's Logische Untersuchungen and the first edition of Karl Jaspers's Allgemeine Psychopathologie. Hist Psychiatry. 1995;6:209–224. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/11639693)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Hist+Psychiatry&title=Phenomenology,+intentionality,+and+metal+experiences:+edmund+Husserl's+Logische+Untersuchungen+and+the+first+edition+of+Karl+Jaspers's+Allgemeine+Psychopathologie&author=M+Langenbach&volume=6&publication_year=1995&pages=209-224&pmid=11639693&)\]

71\. Mundt C. Karl Jaspers. Am J Psychiatry. 1993;150:1244–1245. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8328571)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Am+J+Psychiatry&title=Karl+Jaspers&author=C+Mundt&volume=150&publication_year=1993&pages=1244-1245&pmid=8328571&)\]

72\. Sahner H. Jaspers. Reinbek, Germany: Rowohlt; 1970. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Jaspers&author=H+Sahner&publication_year=1970&)\]

73\. Blankenburg W. Unausgeschöpftes in der psychopathologie von Karl Jaspers. Nervenarzt. 1984;55:447–460. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/6390228)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Unausgeschöpftes+in+der+psychopathologie+von+Karl+Jaspers&author=W+Blankenburg&volume=55&publication_year=1984&pages=447-460&pmid=6390228&)\]

74\. Berrios GE. Phenomenology and psychopathology: was there ever a relationship? Compr Psychiatry. 1993;34:213–220. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8348798)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Compr+Psychiatry&title=Phenomenology+and+psychopathology:+was+there+ever+a+relationship?&author=GE+Berrios&volume=34&publication_year=1993&pages=213-220&pmid=8348798&)\]

75\. Berrios GE. Descriptive psychopathology: conceptual and historical aspects. Psychol Med. 1984;14:303–313. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/6739628)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychol+Med&title=Descriptive+psychopathology:+conceptual+and+historical+aspects&author=GE+Berrios&volume=14&publication_year=1984&pages=303-313&pmid=6739628&)\]

76\. Huber G. Die Bedeutung von Karl Jaspers für die Psychiatrie der Gegenwart. Nervenarzt. 1984;55:1–9. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/6369155)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Die+Bedeutung+von+Karl+Jaspers+für+die+Psychiatrie+der+Gegenwart&author=G+Huber&volume=55&publication_year=1984&pages=1-9&pmid=6369155&)\]

77\. Jaspers K. Philosophische Autobiographie. München, Germany: Piper; 1977. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Philosophische+Autobiographie&author=K+Jaspers&publication_year=1977&)\]

78\. Kraus A. Phenomenological-anthropological psychiatry. In: Henn F, Satorius N, Helmchen H, Lauter H, editors. Contemporary Psychiatry, Vol. 1, Part 1. Berlin, Germany: Springer; 2001. pp. 339–359. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Contemporary+Psychiatry,+Vol.+1,+Part+1&author=A+Kraus&publication_year=2001&)\]

79\. Gruhle HW. Die Schizophrenie. In: Bumke O, editor. Handbuch der Geisteskrankheiten, Vol. 9, Part V. Berlin, Germany: Springer; 1932. pp. 135–210. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handbuch+der+Geisteskrankheiten,+Vol.+9,+Part+V&author=HW+Gruhle&publication_year=1932&)\]

80\. Bumke O. Jaspers, Karl (Heidelberg), Allgemeine Psychopathologie. \[Rezension\] Z Ges Neurol Psychiatr. 1914;9:50–51.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Z+Ges+Neurol+Psychiatr&title=Jaspers,+Karl+(Heidelberg),+Allgemeine+Psychopathologie.+[Rezension]&author=O+Bumke&volume=9&publication_year=1914&pages=50-51&)\]

81\. Schneider K. 25 Jahre “Allgemeine Psychopathologie” von Karl Jaspers. Nervenarzt. 1938;11:281–283.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=25+Jahre+“Allgemeine+Psychopathologie”+von+Karl+Jaspers&author=K+Schneider&volume=11&publication_year=1938&pages=281-283&)\]

82\. Gruhle HW. Karl Jaspers: allgemeine Psychopathologie. Nervenarzt. 1947;18:380–383.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Nervenarzt&title=Karl+Jaspers:+allgemeine+Psychopathologie&author=HW+Gruhle&volume=18&publication_year=1947&pages=380-383&)\]

83\. Peters UH. The emigration of German psychiatrists to Britain. In: Freeman H, Berrios GE, editors. 150 Years of British Psychiatry, Vol. 2: The Aftermath. London, UK: Athlone; 1996. pp. 565–580. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=150+Years+of+British+Psychiatry,+Vol.+2:+The+Aftermath&author=UH+Peters&publication_year=1996&)\]

84\. Lewis A. William Mayer-Gross: an appreciation. Psychol Med. 1970;7:11–18. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/323898)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychol+Med&title=William+Mayer-Gross:+an+appreciation&author=A+Lewis&volume=7&publication_year=1970&pages=11-18&pmid=323898&)\]

85\. Berrios GE. British psychopathology since the early 20th century. In: Berrios GE, Freeman H, editors. 150 years of British psychiatry 1841–1991. London, UK: Gaskell; 1991. pp. 232–244. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=150+years+of+British+psychiatry+1841–1991&author=GE+Berrios&publication_year=1991&)\]

86\. Mullen PE. Ten books. Br J Psychiatry. 2004;185:179–182. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/15468448)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+J+Psychiatry&title=Ten+books&author=PE+Mullen&volume=185&publication_year=2004&pages=179-182&pmid=15468448&)\]

87\. Jaspers K. General Psychopathology. Manchester, UK: University Press; 1963. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=General+Psychopathology&author=K+Jaspers&publication_year=1963&)\]

88\. Fish F. Clinical Psychopathology. Bristol, UK: Wright; 1967. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Clinical+Psychopathology&author=F+Fish&publication_year=1967&)\]

89\. Hamilton M. Fish's Clinical Psychopathology. Bristol, UK: Wright; 1974. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Fish's+Clinical+Psychopathology&author=M+Hamilton&publication_year=1974&)\]

90\. Hoenig J. Karl Jaspers' general psychopathology: the history of the English translation. Hist Psychiatry. 2004;15:233–236. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/15272485)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Hist+Psychiatry&title=Karl+Jaspers'+general+psychopathology:+the+history+of+the+English+translation&author=J+Hoenig&volume=15&publication_year=2004&pages=233-236&pmid=15272485&)\]

91\. Peters UH. Hommage an Kraepelin zu seinem 150. Geburtstag—Zerfahrenheit: kraepelins spezifisches Symptom für Schizophrenie. Fortschr Neurol Psychiatr. 2006;74:656–664. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17103366)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Fortschr+Neurol+Psychiatr&title=Hommage+an+Kraepelin+zu+seinem+150.+Geburtstag—Zerfahrenheit:+kraepelins+spezifisches+Symptom+für+Schizophrenie&author=UH+Peters&volume=74&publication_year=2006&pages=656-664&pmid=17103366&)\]

92\. Decker HS. The psychiatric works of Emil Kraepelin: a many-facted story of modern medicine. J Hist Neurosci. 2004;13:248–276. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/15370311)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=J+Hist+Neurosci&title=The+psychiatric+works+of+Emil+Kraepelin:+a+many-facted+story+of+modern+medicine&author=HS+Decker&volume=13&publication_year=2004&pages=248-276&pmid=15370311&)\]

93\. Bleuler E. Dementia Praecox oder die Gruppe der Schizophrenien. In: Aschaffenburg G, editor. Handbuch der Psychiatrie, Spez. Teil, 4. Abteilung, 1.Hälfte. Leipzig, Germany: Deuticke; 1911. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Handbuch+der+Psychiatrie,+Spez.+Teil,+4.+Abteilung,+1.Hälfte&author=E+Bleuler&publication_year=1911&)\]

94\. Scharfetter C. Schizophrene Menschen: Diagnostik, Psychopathologie, Forschungsansätze. 4th ed. Weinheim, Germany: Beltz; 1995. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Schizophrene+Menschen:+Diagnostik,+Psychopathologie,+Forschungsansätze&author=C+Scharfetter&publication_year=1995&)\]

95\. Berze J. Die Primäre Insuffizienz der Psychischen Aktivität. Leipzig, Germany: Deuticke; 1914. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Die+Primäre+Insuffizienz+der+Psychischen+Aktivität&author=J+Berze&publication_year=1914&)\]

96\. Beringer K. Denkstörungen und sprache der schizophrenen. Z Ges Neurol Psychiatr. 1926;103:407.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Z+Ges+Neurol+Psychiatr&title=Denkstörungen+und+sprache+der+schizophrenen&author=K+Beringer&volume=103&publication_year=1926&pages=407&)\]

97\. Berze J, Gruhle HW. Psychologie der Schizophrenie. Berlin, Germany: Springer; 1929. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Psychologie+der+Schizophrenie&author=J+Berze&author=HW+Gruhle&publication_year=1929&)\]

98\. Rümke HC. Das Kernsyndrom der Schizophrenie und das “Praecox Gefühl” Zbl Ges Neurol Psychiatr. 1942;102:168.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Zbl+Ges+Neurol+Psychiatr&title=Das+Kernsyndrom+der+Schizophrenie+und+das+“Praecox+Gefühl”&author=HC+Rümke&volume=102&publication_year=1942&pages=168&)\]

99\. Conrad K. Die Beginnende Schizophrenie. Stuttgart, Germany: Enke; 1958. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Die+Beginnende+Schizophrenie&author=K+Conrad&publication_year=1958&)\]

100\. Blankenburg W. Der Verlust der Natürlichen Selbstverständlichkeit. Ein Beitrag Zur Psychopathologie Symptomarmer Schizophrenien. Stuttgart, Germany: Enke; 1971. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Der+Verlust+der+Natürlichen+Selbstverständlichkeit.+Ein+Beitrag+Zur+Psychopathologie+Symptomarmer+Schizophrenien&author=W+Blankenburg&publication_year=1971&)\]

101\. Mundt C. Das Apathiesyndrom der Schizophrenen. Berlin, Germany: Springer; 1985. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3878944)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Das+Apathiesyndrom+der+Schizophrenen&author=C+Mundt&publication_year=1985&)\]

102\. Janzarik W. Strukturdynamische Grundlagen der Psychiatrie. Stuttgart, Germany: Enke; 1988. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Strukturdynamische+Grundlagen+der+Psychiatrie&author=W+Janzarik&publication_year=1988&)\]

103\. Gross G, Huber G. Psychopathology and biological-psychiatric research. Neurol Psychiatry Brain Res. 1995;3:161–166.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Neurol+Psychiatry+Brain+Res&title=Psychopathology+and+biological-psychiatric+research&author=G+Gross&author=G+Huber&volume=3&publication_year=1995&pages=161-166&)\]

104\. Klosterkötter J, Ebel H, Schultze-Lutter F, Steinmeyer EM. Diagnostic validity of basic symptoms. Eur Arch Psychiatry Clin Neurosci. 1996;246:147–154. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8739400)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Eur+Arch+Psychiatry+Clin+Neurosci&title=Diagnostic+validity+of+basic+symptoms&author=J+Klosterkötter&author=H+Ebel&author=F+Schultze-Lutter&author=EM+Steinmeyer&volume=246&publication_year=1996&pages=147-154&pmid=8739400&)\]

105\. Klosterkötter J, Ruhrmann S, Schultze-Luther F, et al. Reventlow H, on behalf of the EPOS group. The European prediction of psychosis study (EPOS): integrating early recognition and intervention in Europe. World Psychiatry. 2005;4:161–167.\[ [PMC free article](/pmc/articles/PMC1414769/)\] \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/16633542)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=World+Psychiatry&title=Reventlow+H,+on+behalf+of+the+EPOS+group.+The+European+prediction+of+psychosis+study+(EPOS):+integrating+early+recognition+and+intervention+in+Europe&author=J+Klosterkötter&author=S+Ruhrmann&author=F+Schultze-Luther&volume=4&publication_year=2005&pages=161-167&pmid=16633542&)\]

106\. Andreasen NC. The evolving concept of schizophrenia: from Kraepelin to the present and future. Schizophr Res. 1997;28:105–109. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/9468346)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Res&title=The+evolving+concept+of+schizophrenia:+from+Kraepelin+to+the+present+and+future&author=NC+Andreasen&volume=28&publication_year=1997&pages=105-109&pmid=9468346&)\]

107\. Schneider K. Clinical Psychopathology. New York, NY: Grune & Stratton; 1959. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Clinical+Psychopathology&author=K+Schneider&publication_year=1959&)\]

108\. WHO. The International Pilot Study of Schizophrenia, Vol. 1. Geneva, Switzerland: WHO; 1973. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=The+International+Pilot+Study+of+Schizophrenia,+Vol.+1&publication_year=1973&)\]

109\. Endicott J, Nee J, Cohen J, Fleiss JL, Simon R. Diagnosis of schizophrenia. Prediction of short-term outcome. Arch Gen Psychiatry. 1986;43:13–19. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3942470)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=Diagnosis+of+schizophrenia.+Prediction+of+short-term+outcome&author=J+Endicott&author=J+Nee&author=J+Cohen&author=JL+Fleiss&author=R+Simon&volume=43&publication_year=1986&pages=13-19&pmid=3942470&)\]

110\. Tandon R, Greden JF. Schneiderian first-rank symptoms: reconfirmation of high specificity for schizophrenia. Acta Psychiatr Scand. 1987;75:392–396. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/2884810)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Acta+Psychiatr+Scand&title=Schneiderian+first-rank+symptoms:+reconfirmation+of+high+specificity+for+schizophrenia&author=R+Tandon&author=JF+Greden&volume=75&publication_year=1987&pages=392-396&pmid=2884810&)\]

111\. O'Grady JC. The prevalence and diagnostic significance of Schneiderian first-rank symptoms in a random sample of acute psychiatric in-patients. Br J Psychiatry. 1990;156:496–500. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/2386859)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+J+Psychiatry&title=The+prevalence+and+diagnostic+significance+of+Schneiderian+first-rank+symptoms+in+a+random+sample+of+acute+psychiatric+in-patients&author=JC+O'Grady&volume=156&publication_year=1990&pages=496-500&pmid=2386859&)\]

112\. Dilling H, Mombour W, Schmidt MH. Internationale Klassifikation Psychischer Störungen: ICD-10. Bern, Switzerland: Huber; 1991. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Internationale+Klassifikation+Psychischer+Störungen:+ICD-10&author=H+Dilling&author=W+Mombour&author=MH+Schmidt&publication_year=1991&)\]

113\. Carpenter WT, Jr, Arango C, Buchanan RW, Kirkpatrick B. Deficit psychopathology and a paradigm shift in schizophrenia research. Biol Psychiatry. 1999;46:352–360. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/10435200)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Biol+Psychiatry&title=Deficit+psychopathology+and+a+paradigm+shift+in+schizophrenia+research&author=WT+Carpenter&author=C+Arango&author=RW+Buchanan&author=B+Kirkpatrick&volume=46&publication_year=1999&pages=352-360&pmid=10435200&)\]

114\. Crichton P. First-rank symptoms or rank-and-file symptoms? Br J Psychiatry. 1996;169:537–540. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8932880)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+J+Psychiatry&title=First-rank+symptoms+or+rank-and-file+symptoms?&author=P+Crichton&volume=169&publication_year=1996&pages=537-540&pmid=8932880&)\]

115\. Silverstein ML, Harrow M. Schneiderian first-rank symptoms in schizophrenia. Arch Gen Psychiatry. 1981;38:288–293. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/7212959)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=Schneiderian+first-rank+symptoms+in+schizophrenia&author=ML+Silverstein&author=M+Harrow&volume=38&publication_year=1981&pages=288-293&pmid=7212959&)\]

116\. Crow TJ. The molecular pathology of schizophrenia: more than one disease process? Br Med J. 1980;280:66–68.\[ [PMC free article](/pmc/articles/PMC1600263/)\] \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/6101544)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Br+Med+J&title=The+molecular+pathology+of+schizophrenia:+more+than+one+disease+process?&author=TJ+Crow&volume=280&publication_year=1980&pages=66-68&pmid=6101544&)\]

117\. Carpenter WT, Jr, Heinrichs DW, Wagman AMI. Deficit and non-deficit forms of schizophrenia: the concept. Am J Psychiatry. 1988;145:578–583. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3358462)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Am+J+Psychiatry&title=Deficit+and+non-deficit+forms+of+schizophrenia:+the+concept&author=WT+Carpenter&author=DW+Heinrichs&author=AMI+Wagman&volume=145&publication_year=1988&pages=578-583&pmid=3358462&)\]

118\. Andreasen NC. Improvement of negative symptoms: concepts, definition and assessment. Int Clin Psychopharmacol. 1997;12:S7–S10. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/9218162)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Int+Clin+Psychopharmacol&title=Improvement+of+negative+symptoms:+concepts,+definition+and+assessment&author=NC+Andreasen&volume=12&publication_year=1997&pages=S7-S10&pmid=9218162&)\]

119\. Andreasen NC, Carpenter WT., Jr Diagnosis and classification of schizophrenia. Schizophr Bull. 1993;19:199–214. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/8322032)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Bull&title=Diagnosis+and+classification+of+schizophrenia&author=NC+Andreasen&author=WT+Carpenter&volume=19&publication_year=1993&pages=199-214&pmid=8322032&)\]

120\. Andreasen NC. A unitary model of schizophrenia: Bleuler's “fragmented phrene” as schizencephaly. Arch Gen Psychiatry. 1999;56:781–787. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/12884883)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Arch+Gen+Psychiatry&title=A+unitary+model+of+schizophrenia:+Bleuler's+“fragmented+phrene”+as+schizencephaly&author=NC+Andreasen&volume=56&publication_year=1999&pages=781-787&pmid=12884883&)\]

121\. Sass LA, Parnas J. Schizophrenia, consciousness, and the self. Schizophr Bull. 2003;29:427–444. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/14609238)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Bull&title=Schizophrenia,+consciousness,+and+the+self&author=LA+Sass&author=J+Parnas&volume=29&publication_year=2003&pages=427-444&pmid=14609238&)\]

122\. Elkhazen C, Chauchot F, Canceil O, Krebs MO, Bayle FJ. Prodromal symptoms of schizophrenia. Encephale. 2003;29:469–477. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/15029081)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Encephale&title=Prodromal+symptoms+of+schizophrenia&author=C+Elkhazen&author=F+Chauchot&author=O+Canceil&author=MO+Krebs&author=FJ+Bayle&volume=29&publication_year=2003&pages=469-477&pmid=15029081&)\]

123\. Yung AR, Philips LJ, Yuen HP, McGorry PD. Risk factors for psychosis in an ultra-high risk group: psychopathology and clinical features. Schizophr Res. 2004;67:131–142. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/14984872)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Res&title=Risk+factors+for+psychosis+in+an+ultra-high+risk+group:+psychopathology+and+clinical+features&author=AR+Yung&author=LJ+Philips&author=HP+Yuen&author=PD+McGorry&volume=67&publication_year=2004&pages=131-142&pmid=14984872&)\]

124\. Hafner H, Maurer K, Trendler G, an der Heiden W, Schmidt M. The early course of schizophrenia and depression. Eur Arch Psychiatry Clin Neurosci. 2005;255:167–173. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/15995900)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Eur+Arch+Psychiatry+Clin+Neurosci&title=The+early+course+of+schizophrenia+and+depression&author=H+Hafner&author=K+Maurer&author=G+Trendler&author=W+an+der+Heiden&author=M+Schmidt&volume=255&publication_year=2005&pages=167-173&pmid=15995900&)\]

125\. Cannon TD, Cornblatt B, McGorry P. Editor's introduction: the empirical status of the ultra high-risk (prodromal) research paradigm. Schizophr Bull. 2007;33:661–664.\[ [PMC free article](/pmc/articles/PMC2526144/)\] \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17470445)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Bull&title=Editor's+introduction:+the+empirical+status+of+the+ultra+high-risk+(prodromal)+research+paradigm&author=TD+Cannon&author=B+Cornblatt&author=P+McGorry&volume=33&publication_year=2007&pages=661-664&pmid=17470445&)\]

126\. Huber G. Prodrome der Schizophrenie. Fortschr Neurol Psychiatr. 1995;63:131–138. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/7759051)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Fortschr+Neurol+Psychiatr&title=Prodrome+der+Schizophrenie&author=G+Huber&volume=63&publication_year=1995&pages=131-138&pmid=7759051&)\]

127\. Huber G. The psychopathology of K. Jaspers and K. Schneider as a fundamental method for psychiatry. World J Biol Psychiatry. 2002;3:50–57. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/12479088)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=World+J+Biol+Psychiatry&title=The+psychopathology+of+K.+Jaspers+and+K.+Schneider+as+a+fundamental+method+for+psychiatry&author=G+Huber&volume=3&publication_year=2002&pages=50-57&pmid=12479088&)\]

128\. Klosterkötter J. Basissymptome und Endphänomene der Schizophrenie. Berlin, Germany: Springer; 1988. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/3173370)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Basissymptome+und+Endphänomene+der+Schizophrenie&author=J+Klosterkötter&publication_year=1988&)\]

129\. Gross G, Huber G, Klosterkötter J, Linz M. Bonner Skala für die Beurteilung von Basissymptomen. Berlin, Germany: Springer; 1987. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Bonner+Skala+für+die+Beurteilung+von+Basissymptomen&author=G+Gross&author=G+Huber&author=J+Klosterkötter&author=M+Linz&publication_year=1987&)\]

130\. Klosterkötter J, Schultze-Lutter F, Gross G, Huber G, Steinmeyer EM. Early self-experienced neuropsychological deficits and subsequent schizophrenic diseases: an 8-year average follow-up prospective study. Acta Psychiatr Scand. 1997;95:396–404. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/9197904)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Acta+Psychiatr+Scand&title=Early+self-experienced+neuropsychological+deficits+and+subsequent+schizophrenic+diseases:+an+8-year+average+follow-up+prospective+study&author=J+Klosterkötter&author=F+Schultze-Lutter&author=G+Gross&author=G+Huber&author=EM+Steinmeyer&volume=95&publication_year=1997&pages=396-404&pmid=9197904&)\]

131\. Pukrop R, Ruhrmann S, Schultze-Lutter F, Bechdolf A, Brockhaus-Dumke A, Klosterkötter J. Neurocognitive indicators for a conversion to psychosis: comparison of patients in a potentially initial prodromal state who did or did not convert to a psychosis. Schizophr Res. 2007;92:116–125. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17344028)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Res&title=Neurocognitive+indicators+for+a+conversion+to+psychosis:+comparison+of+patients+in+a+potentially+initial+prodromal+state+who+did+or+did+not+convert+to+a+psychosis&author=R+Pukrop&author=S+Ruhrmann&author=F+Schultze-Lutter&author=A+Bechdolf&author=A+Brockhaus-Dumke&volume=92&publication_year=2007&pages=116-125&pmid=17344028&)\]

132\. Pukrop R, Schultze-Lutter F, Ruhrmann S, et al. Neurocognitive functioning in subjects at risk for a first episode of psychosis compared with first- and multiple-episode schizophrenia. J Clin Exp Neuropsychol. 2006;28:1388–1407. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17050266)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=J+Clin+Exp+Neuropsychol&title=Neurocognitive+functioning+in+subjects+at+risk+for+a+first+episode+of+psychosis+compared+with+first-+and+multiple-episode+schizophrenia&author=R+Pukrop&author=F+Schultze-Lutter&author=S+Ruhrmann&volume=28&publication_year=2006&pages=1388-1407&pmid=17050266&)\]

133\. Keefe RS, Perkins DO, Gu H, Zipursky RB, Christensen BK, Lieberman JA. A longitudinal study of neurocognitive function in individuals at-risk for psychosis. Schizophr Res. 2006;88:26–35. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/16930949)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Res&title=A+longitudinal+study+of+neurocognitive+function+in+individuals+at-risk+for+psychosis&author=RS+Keefe&author=DO+Perkins&author=H+Gu&author=RB+Zipursky&author=BK+Christensen&volume=88&publication_year=2006&pages=26-35&pmid=16930949&)\]

134\. Eastvold AD, Heaton RK, Cadenhead KS. Neurocognitive deficits in the (putative) prodrome and first episode of psychosis. Schizophr Res. 2007;93:266–277.\[ [PMC free article](/pmc/articles/PMC2080673/)\] \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17467955)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Schizophr+Res&title=Neurocognitive+deficits+in+the+(putative)+prodrome+and+first+episode+of+psychosis&author=AD+Eastvold&author=RK+Heaton&author=KS+Cadenhead&volume=93&publication_year=2007&pages=266-277&pmid=17467955&)\]

135\. Parnas J, Zahavi D. The role of phenomenology in psychiatric classification and diagnosis. In: Maj M, Gaebel W, Lobez-Ibor JJ, Sartorius N, editors. World Psychiatric Association Series: Psychiatric Diagnosis and Classification. Chichester, UK: Wiley; 2002. pp. 137–162. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=World+Psychiatric+Association+Series:+Psychiatric+Diagnosis+and+Classification&author=J+Parnas&author=D+Zahavi&publication_year=2002&)\]

136\. Bürgy M. Psychopathology of obsessive-compulsive disorder: a phenomenological approach. Psychopathology. 2005;38:291–300. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/16224202)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychopathology&title=Psychopathology+of+obsessive-compulsive+disorder:+a+phenomenological+approach&author=M+Bürgy&volume=38&publication_year=2005&pages=291-300&pmid=16224202&)\]

137\. Bürgy M. Obsession in the strict sense: a helpful psychopathological phenomenon in the differential diagnosis between obsessive-compulsive disorder and schizophrenia. Psychopathology. 2007;40:102–110. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/17215596)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychopathology&title=Obsession+in+the+strict+sense:+a+helpful+psychopathological+phenomenon+in+the+differential+diagnosis+between+obsessive-compulsive+disorder+and+schizophrenia&author=M+Bürgy&volume=40&publication_year=2007&pages=102-110&pmid=17215596&)\]

138\. Kisker KP. Der Erlebniswandel des Schizophrenen. Ein psychopathologischer Beitrag zur Psychonomie schizophrener Grundsituationen. Berlin, Germany: Springer; 1960. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Der+Erlebniswandel+des+Schizophrenen.+Ein+psychopathologischer+Beitrag+zur+Psychonomie+schizophrener+Grundsituationen&author=KP+Kisker&publication_year=1960&)\]

139\. Bleuler M. Lehrbuch der Psychiatrie. 13th ed. Berlin, Germany: Springer; 1975. \[ [Google Scholar](https://scholar.google.com/scholar_lookup?title=Lehrbuch+der+Psychiatrie&author=M+Bleuler&publication_year=1975&)\]

140\. Parnas J, Handest P. Phenomenology of anomalous self-experience in early schizophrenia. Compr Psychiatry. 2003;44:121–134. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/12658621)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Compr+Psychiatry&title=Phenomenology+of+anomalous+self-experience+in+early+schizophrenia&author=J+Parnas&author=P+Handest&volume=44&publication_year=2003&pages=121-134&pmid=12658621&)\]

141\. Zahavi D, Parnas J. Phenomenal consciousness and self-awareness: a phenomenological critique of representational theory. J Conscious Stud. 1998;5:687–705.\[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=J+Conscious+Stud&title=Phenomenal+consciousness+and+self-awareness:+a+phenomenological+critique+of+representational+theory&author=D+Zahavi&author=J+Parnas&volume=5&publication_year=1998&pages=687-705&)\]

142\. Parnas J, Handest P, Lennart J, Saebye D. Anomalous subjective experience among first-admitted schizophrenia spectrum patients: empirical investigation. Psychopathology. 2005;38:259–267. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/16179812)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychopathology&title=Anomalous+subjective+experience+among+first-admitted+schizophrenia+spectrum+patients:+empirical+investigation&author=J+Parnas&author=P+Handest&author=J+Lennart&author=D+Saebye&volume=38&publication_year=2005&pages=259-267&pmid=16179812&)\]

143\. Parnas J, Moller P, Kircher T, et al. EASE: Examination of Anomalous Self-Experience. Psychopathology. 2005;38:236–258. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/16179811)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Psychopathology&title=EASE:+Examination+of+Anomalous+Self-Experience&author=J+Parnas&author=P+Moller&author=T+Kircher&volume=38&publication_year=2005&pages=236-258&pmid=16179811&)\]

144\. Parnas J. Genetics and psychopathology of spectrum phenotypes. Acta Psychiatr Scand. 2000;101:413–415. \[ [PubMed](https://pubmed.ncbi.nlm.nih.gov/10868464)\] \[ [Google Scholar](https://scholar.google.com/scholar_lookup?journal=Acta+Psychiatr+Scand&title=Genetics+and+psychopathology+of+spectrum+phenotypes&author=J+Parnas&volume=101&publication_year=2000&pages=413-415&pmid=10868464&)\]

* * *

Articles from Schizophrenia Bulletin are provided here courtesy of **Oxford University Press**

* * *

###### Other Formats

- [PDF (114K)](/pmc/articles/PMC2632489/pdf/sbm136.pdf)

###### Actions

- Cite
- Collections





Add to Collections







- Create a new collection
- Add to an existing collection

Name your collection:


Name must be less than characters


Choose a collection:


Unable to load your collection due to an error

Please try again

Add

Cancel


###### Share

- Permalink




Copy


###### RESOURCES

- Similar articles


- Cited by other articles


- Links to NCBI Databases



\[x\]

Cite

Copy
Download .nbib.nbib

Format:
AMA

APA

MLA

NLM


Follow NCBI

[Twitter](https://twitter.com/ncbi) [Facebook](https://www.facebook.com/ncbi.nlm) [LinkedIn](https://www.linkedin.com/company/ncbinlm) [GitHub](https://github.com/ncbi) [Blog](https://ncbiinsights.ncbi.nlm.nih.gov/)

[Connect with NLM](https://www.nlm.nih.gov/socialmedia/index.html)

- [SM-Twitter](https://twitter.com/NLM_NIH)
- [SM-Facebook](https://www.facebook.com/nationallibraryofmedicine)
- [SM-Youtube](https://www.youtube.com/user/NLMNIH)

National Library of Medicine

[8600 Rockville Pike\
\
Bethesda, MD 20894](https://www.google.com/maps/place/8600+Rockville+Pike,+Bethesda,+MD+20894/@38.9959508,-77.101021,17z/data=!3m1!4b1!4m5!3m4!1s0x89b7c95e25765ddb:0x19156f88b27635b8!8m2!3d38.9959508!4d-77.0988323)

[Web Policies](https://www.nlm.nih.gov/web_policies.html)

[FOIA](https://www.nih.gov/institutes-nih/nih-office-director/office-communications-public-liaison/freedom-information-act-office)

[HHS Vulnerability Disclosure](https://www.hhs.gov/vulnerability-disclosure-policy/index.html)

[Help](https://support.nlm.nih.gov/)

[Accessibility](https://www.nlm.nih.gov/accessibility.html)

[Careers](https://www.nlm.nih.gov/careers/careers.html)

- [NLM](//www.nlm.nih.gov/)
- [NIH](https://www.nih.gov/)
- [HHS](https://www.hhs.gov/)
- [USA.gov](https://www.usa.gov/)