Diagnostic stability in patients with first-episode psychosis.

Objective: To examine the short-term stability of Diagnostic and Statistical Manual of Mental Disorders (4th edn; DSM-IV) and International Classification of Diseases (10th revision; ICD-10) diagnoses in a group of patients with first-episode psychosis.

Method: Sixty patients with first-episode psychosis admitted consecutively to Roozbeh Hospital, Tehran, were sampled; their illnesses could not be attributed to any medical or substance-induced conditions. Patients were assessed at the time of discharge from the hospital, and at 3, 6 and 12 month intervals following admission. At each visit, two psychiatrists made consensus DSM-IV and ICD-10 diagnoses, based on all available information. Stability was discerned as the consistency between diagnoses at the time of discharge and at 12 month follow up.

Results: Forty-eight patients completed follow up. Affective psychotic disorders and schizophrenia in both classification systems were highly stable. In addition, all patients with DSM-IV brief psychotic disorder and ICD-10 acute and transient psychotic disorders remained the same at follow up.

Conclusions: Affective psychoses and schizophrenia, in line with previous findings, remained stable. Diagnoses of brief psychoses were highly stable as well; this could reflect a non-relapsing course of acute brief psychoses, especially in developing countries.