<unk>  was listed under Factitious Disorder with Psychological Symptoms in the DSM-III. The criteria of this category emphasized symptoms that cannot be explained by other mental disorders, psychological symptoms under the control of the individual, and the goal of assuming a patient role, not otherwise understandable given their circumstances. The DSM-IV-TR classified<unk>  as a dissociative disorder defined by the giving of approximate answers to questions (e.g. '2 plus 2 equals 5' when not associated with dissociative amnesia or dissociative fugue). The ICD-10 and DSM-IV do not specify any diagnostic criteria—apart from approximate answers—as a requirement for a<unk>  diagnosis. Most case studies of the syndrome also depend on the presence of approximate answers and at least one of the other symptoms described by<unk>  in his original paper. Usually when giving wrong answers, individuals are only slightly off, showing that the individual understood the question For instance, when asked how many legs a horse has, they might say, "five". Although subjects appear confused in their answers, in other respects they appear to understand their surroundings. Amnesia, loss of personal identity, and clouding of consciousness were among the most common symptoms apart from approximate answers. Although there is currently no uniform way to diagnose the syndrome, a full neurological and mental state examination is recommended to determine its presence as well as tests that assess malingering. In addition to mental examination, other investigations should be done to exclude other underlying causes. These include computer tomography scans (CT) or magnetic resonance imaging (MRI) scans to exclude structural pathology, lumbar puncture to exclude meningitis or encephalitis, and electroencephalography (EEG), to exclude delirium or seizure disorder. Diagnosing<unk>  is challenging because of its rarity and symptom variability. The manifested symptoms may be dependent on the individual's conception of what mental illness entails, creating the possibility of a wide range of combinations of symptoms present in an individual with<unk> .
Ganser syndrome
Leschke syndrome
Temple–Baraitser syndrome
Schimmelpenning syndrome
Antley–Bixler syndrome
Catel–Manzke syndrome
Eiken syndrome
Gleich's syndrome