Shared psychotic disorder

Schizophreniform disorder in DSM-FV is somewhat different from schizotypal disorder in ICD-10. The diagnosis of schizophreniform disorder requires the identical criteria of schizophrenia (criterion A), except for two differences the total duration of the illness is at least 1 month, but less than 6 months (criterion B), and impaired social or occupational functioning during some part of the illness is not required. The delusional disorder in DSM-IV corresponds more or less to the category persistent delusional disorder of ICD-10, and brief psychotic disorder (DSM-IV) is similar to the ICD-10 category acute and transient psychotic disorder, whereas the shared psychotic disorder of DSM-IV corresponds to induced delusional disorder of ICD-10. 

In shared psychotic disorder (e.g., folie a deux), a close friend or relative passively accepts the delusional belief system of the more dominant member. Thus, the symptoms may not necessarily be truly delusional, and often remit when the individual is separated from the inducer or primary case. ... 

Various other psychotic disorders, such as brief psychotic disorder, delusional disorder, shared psychotic disorder, substance-induced psychotic disorder, and psychotic disorder not otherwise specified (94)... 

Those disorders that require the presence of psychosis (Table 10—1) as a defining feature of the diagnosis include schizophrenia, substance-induced (i.e., drug-induced) psychotic disorder, schizophreniform disorder, schizoaffective disorder, delusional disorder, brief psychotic disorder, shared psychotic disorder, and psychotic disorder due to a general medical condition. Disorders that may or may not have psychotic symptoms (Table 10—2) as an associated feature include mania and depression as well as several cognitive disorders such as Alzheimer s dementia. 

Schizoaffective disorder Individuals who suffer from this disorder experience the signs and symptoms prevalent in both the schizophrenic disorder and the mood disorder. Shared psychotic disorder aka induced psychotic disorden This disorder is often found in rural areas and historically has been referred to as the folie a deux. In this disorder two people generally share the same delusional system. 

Antipsychotic drugs are also indicated for schizoaffective disorders, which share characteristics of both schizophrenia and affective disorders. No fundamental difference between these two diagnoses has been reliably demonstrated. They are part of a continuum with bipolar psychotic disorder. The psychotic aspects of the illness require treatment with antipsychotic drugs, which may be used with other drugs such as antidepressants, lithium, or valproic acid. The manic phase in bipolar affective disorder often requires treatment with antipsychotic agents, although lithium or valproic acid supplemented with high-potency benzodiazepines (eg, lorazepam or clonazepam) may suffice in milder cases. Recent controlled trials support the efficacy of monotherapy with atypical antipsychotics in the acute phase (up to 4 weeks) of mania, and olanzapine and quetiapine has been approved for this indication. 

Methylphenidate shares the pharmacological properties and the abuse potential of the amphetamines. When given intravenously, it activates psychotic symptoms in schizophrenic patients if administered during the active phase of their illness, but not after remission. It failed to produce a psychotic reaction in most manic or depressed patients or in healthy subjects (27). Adults with childhood-onset ADHD had an earlier onset of psychoactive substance use disorders, independent of any psychiatric co-morbidity (33). However, bipolar disorders conferred a significantly increased risk for early onset psychoactive substance use disorders independent of ADHD. The question arises as to the contribution of stimulant treatment to psychoactive substance use disorders. There were no differences in medicated versus unmedicated adolescents with ADHD in a review of eight outcome studies comprising 580 adolescents briefly treated with stimulants for six months to five years (34). 

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