Duration of untreated psychosis (DUP) and the course of schizophrenia in a 20-year follow-up study.

Our aims were to analyze the relationship between the duration of psychosis (DUP) and short- and long-term outcomes of treatment, and to determine the cut-off point between short and long DUP at which differences in treatment outcomes are most significant. We assessed 80 participants with schizophrenia at the point of their first hospitalization. Fifty participated in all four follow-ups over 20 years. DUP was divided into short (up to 6 months) and long (over 6 months). ANOVA and Chi-square tests were employed to identify significant differences in both clinical and social indicators of functioning. ROC curves were used to estimate the best DUP division point. Significant differences favoring the short-DUP group were found for: GAF, total severity of symptoms and severity of positive symptoms, social functioning measured according to DSM-III criteria, employment, and social contacts. The optimal cut-off point for DUP was the 23rd week. We concluded that: (1) the relationship between longer DUP and worse overall treatment outcomes was sustained throughout the 20 years, (2) a positive correlation between DUP and the severity of psychopathological symptoms was observed over the first 12 years of illness, (3) the results indicate the efficacy of early therapeutic interventions in psychosis.