The evaluation and treatment of first-episode psychosis.

A first episode of psychosis is a traumatic experience for patients and families. At the time of initial evaluation, the differential diagnosis should include a broad range of neurological, general medical, and psychiatric conditions. Methodological advances in operationally defining illness onset, "offset," and remission have allowed more careful studies of treatment response in first-episode patients. These studies strongly support the efficacy of antipsychotic medication as both acute and maintenance treatment for patients with a first episode of psychosis. The optimal duration of maintenance treatment, however, has not been determined, and patients at low risk for relapse following medication withdrawal cannot be identified with specificity. First-episode psychotic patients typically experience 12 to 24 months of psychosis before receiving treatment, and a long duration of untreated psychosis may be associated with a poorer treatment response. Early intervention may improve outcome in first-episode psychosis, and the use of novel antipsychotics with improved efficacy and fewer side effects may improve medication compliance and reduce morbidity associated with repeated relapses.