Acute and transient psychotic disorders: precursors, epidemiology, course and outcome.

BACKGROUND ICD-10 has introduced the diagnostic group acute and transient psychotic disorders (ATPDs; F23). AIMS To validate the nosological distinctiveness of ICD-10 ATPDs by following up an inception cohort with first-episode psychosis. METHOD All patients with first-episode psychosis identified in Nottingham between 1992 and 1994 and diagnosed using ICD-10 criteria were reassessed 3 years later. ATPD outcomes were compared with schizophrenia and affective psychosis. Multivariate analyses were conducted to determine whether acute onset and early remission predicted favourable 3-year outcome in first-episode psychosis. RESULTS Of 168 cases of first-episode psychosis, 32 (19%) received an intake diagnosis of ATPD. The diagnosis of ATPD was stable in women over 3 years, but not in men. Outcomes in ATPD were better than in schizophrenia and similar to affective psychosis. In non-affective psychoses, favourable outcomes were a function of gender and premorbid functioning rather than acute onset and early remission. CONCLUSIONS The ICD-10 criteria for ATPDs identify a diagnostically unstable group of disorders. Acute onset and early remission do not independently predict favourable outcome over 3 years in first-episode psychosis.