Chronic hallucinatory psychosis
Chronic hallucinatory psychosis is a psychosis subtype, classified under "Other nonorganic psychosis" by the ICD-10 Chapter V: Mental and behavioural disorders. Other abnormal mental symptoms in the early stages are, as a rule, absent. The patient is most usually quiet and orderly, with a good memory. First described by Ballet, during 1912, it has often been a matter of the greatest difficulty to decide under which heading of the recognized classifications individual members of this group should be placed. As the hallucinations give rise to slight depression, some might possibly be included under melancholia. In others, paranoia may develop. Others, again, might be swept into the widespread net of dementia praecox. This state of affairs cannot be regarded as satisfactory, for they are not truly cases of melancholia, paranoia, dementia praecox or any other described affection. This disease, as its name suggests, is a hallucinatory case, for it is its main feature. These may be of all senses, but auditory hallucinations are the most prominent. At the beginning, the patient may realize that the hallucination is a morbid phenomenon and unaccountable. They may claim to hear a "voice" speaking, though there is no one in the flesh actually doing so.