|Classification and external resources|
Ganser syndrome is a rare dissociative disorder previously classified as a factitious disorder. It is characterized by nonsensical or wrong answers to questions or doing things incorrectly, other dissociative symptoms such as fugue, amnesia or conversion disorder, often with visual pseudohallucinations and a decreased state of consciousness. It is also sometimes called nonsense syndrome, balderdash syndrome, syndrome of approximate answers, pseudodementia, hysterical pseudodementia or prison psychosis. This last name, prison psychosis, is sometimes used because the syndrome occurs most frequently in prison inmates, where it may represent an attempt to gain leniency from prison or court officials.
Ganser is an extremely rare variation of dissociative disorder. It is a reaction to extreme stress and the patient thereby suffers from approximation or giving absurd answers to simple questions. The syndrome can sometimes be diagnosed as merely malingering, but it is more often defined as dissociative disorder.
Symptoms include a clouding of consciousness, somatic conversion symptoms, confusion, stress, loss of personal identity, echolalia, and echopraxia. The psychological symptoms generally resemble the patient's sense of mental illness rather than any recognized category. Individuals also give approximate answers to simple questions. For example, "How many legs are on a cat?", to which the subject may respond 'Three'.
The syndrome may occur in persons with other mental disorders such as schizophrenia, depressive disorders, toxic states, paresis, alcohol use disorders and factitious disorders. EEG data does not suggest any specific organic cause.
The original description by Sigbert Josef Maria Ganser in 1898 pointed out their hysterical twilight state. They may also describe hallucinations which are usually more florid than those in schizophrenia. They may also have disorders of sensation similar to those in conversion disorder. They may be inattentive or drowsy.
Some workers believe there is a genuine psychosis underlying this, others believe it is a dissociative disorder, while still others believe it is the result of malingering. Over the years, opinions have seemed to move from the last view more towards the first.
Ganser syndrome is currently classified under dissociative disorders, to which it moved in the DSM IV from the factitious disorders.
According to the DSM-IV-TR, which classifies Ganser syndrome as a dissociative disorder, it is "the giving of approximate answers to questions (e.g. '2 plus 2 equals 5' when not associated with dissociative amnesia or dissociative fugue)."
Diagnosing Ganser syndrome is very challenging, not only because some measure of dishonesty is involved but also because it is very rare.
Usually when giving wrong answers, they 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." Also, although subjects appear confused in their answers, in other respects they appear to understand their surroundings.
Hospitalization may be necessary during the acute phase of symptoms, and psychiatric care if the patient is a danger to self or others. A neurological consult is advised to rule out any organic cause. 
The disorder is extraordinarily rare. While individuals of all backgrounds have been reported with the disorder, there is a higher inclination towards males (75% or more). The average age of those with Ganser syndrome is 32 and it stretches from ages 15–62 years old. It has been reported in children.
The disorder is apparently most common in men and prisoners although prevalence data and familial patterns are not established.
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