Duration of untreated psychosis as predictor of long-term outcome in schizophrenia: systematic review and meta-analysis

Duration of untreated psychosis (DUP) is one of the few potentially modifiable predictors of outcomes of schizophrenia. Long DUP as a predictor of poor short-term outcome has been addressed in previous meta-analyses, but the long-term effects of DUP remain unclear. To analyse the associations between DUP and long-term outcomes of schizophrenia. A systematic literature search was performed using seven electronic databases and manual searches. Random effects weighted meta-analysis with correlation coefficients was used to pool the results. We identified 3493 unique publications, from which 33 samples met our predefined selection criteria. Long DUP correlated statistically significantly with poor general symptomatic outcome, more severe positive and negative symptoms, lesser likelihood of remission and poor social functioning and global outcome (correlations 0.13-0.18). Long DUP was not associated with employment, quality of life or hospital treatment. The small but mostly consistent correlation between long DUP and poor outcome indicates that early intervention in psychosis may have at least subtle positive effects on the long-term course of illness.