This disorder is similar to but milder than schizophrenia. Symptoms (positive or negative) last between one and six months, and patients are able to function socially and at work during this time. When symptoms persist beyond six months in duration, the diagnosis is changed to schizophrenia. Not surprisingly, individuals with schizophreniform disorder are at increased risk for developing schizophrenia.
The following diagnostic criteria must be met before a diagnosis of Schizophreniform Disorder is warranted, according to the DSM-IV-TR:
A) Criterion A, D, and E of Schizophrenia are met.
B) An episode of the disorder (including prodromal, active and residual phases) lasts at least 1 month but less than 6 months. (When the diagnosis must be made without waiting for recovery, it should be qualified as "Provisional").
Psychotic Disorder NOS
A final diagnostic category also exists so that "miscellaneous psychoses" which cannot yet find better diagnostic homes elsewhere can be recognized. The NOS category (Not Otherwise Specified), is often used to describe patient's psychotic states early on in the diagnostic process, when it is not clear how best to classify symptoms. As patients' conditions become better understood (with the passage of time, diagnostic testing, and history gathering) the NOS classification is often removed and a more precise diagnosis is made.