Clinical characteristics, 4-year course, and DSM-IV classification of patients with nonaffective acute remitting psychosis

Objective: The authors examined the clinical characteristics and 48-month illness course of cases of nonaffective acute remitting psychosis and described the classification of these cases in the DSM-IV system. Method: The data were derived from the Suffolk County (N.Y.) Mental Health Project, a study of first-admission patients with psychotic disorders admitted to psychiatric facilities between September 1989 and December 1995. The authors compared the demographic and clinical characteristics, 48-month course, and longitudinal research diagnoses of 16 patients with nonaffective acute remitting psychosis, defined by onset in 2 weeks or less and duration of less than 6 months, to those of 26 patients with other nonaffective remitting psychoses. Results: Nonaffective acute remitting psychosis had a distinctly benign course - 46% of the patients remained in full remission throughout the 48-month follow-up, compared with 14% of patients with other remitting psychoses. Nonaffective acute remitting psychosis was also associated with fewer negative symptoms than other remitting psychoses. By 24-month follow-up, only 6% of the patients with nonaffective acute remitting psychosis, compared with 77% of the patients with other remitting psychoses, received a research diagnosis of schizophrenia or schizoaffective disorder, whereas 44% of patients with nonaffective acute remitting psychosis, compared with 12% of patients with other remitting psychoses, were given the residual diagnosis of psychotic disorder not otherwise specified. Conclusions: Nonaffective acute remitting psychosis is a highly distinctive yet not adequately classified condition. Better delineation of nonaffective acute remitting psychosis in current diagnostic systems could lead to better understanding of this condition and improve the applicability of diagnostic systems in developing countries, where these conditions are more common than in industrialized countries.