Duration of untreated psychosis (DUP) is one of the few potentially modifiable predictors of outcome in schizophrenia. The long DUP and its relation to poor short-term outcome of schizophrenia has been studied in meta-analyses, but the conclusions remain unclear regarding the long-term effects of DUP.

To study the association between DUP and long-term outcome in a meta-analysis.

A systematic literature search of studies on DUP and long-term outcome in schizophrenia was performed using seven electronic databases. Studies were included if the follow-up was at least two years, the majority of subjects had a diagnosis of schizophrenia and DUP was studied with at least one of the following outcome categories: positive, negative, general and total symptoms, need of treatment, social functioning, employment, global outcome, quality of life and remission. Random effect methods were used to pool the effects of original studies.

2636 unique publications were identified of which 37 met our pre-defined selection criteria. Long DUP correlated with more severe positive (number of studies n=16; r=0.17), negative (n=17; r=0.14), general (n=4; r=0.29) and total symptoms (n=7; r=0.14) and with poor social functioning (n=13; r=0.13), poor global outcome (n=15; r=0.22) and less likely remission (n=16; r=0.14). The association between long DUP and decreased need of treatment was close to statistical significance (n=12; r=0.12). Employment (n=5) and quality of life (n=5) were not associated with DUP.

Severe symptoms and decreased functionality does not seem to increase the need of treatment or decrease the quality of life or employment.