The relationship between duration of untreated psychosis and outcome: an eight-year prospective study

Longer duration of untreated psychosis (DUP) prior to the initiation of treatment has been found to predict poorer short-term clinical and functional outcomes in patients with first-episode psychosis (FEP). The extent to which the relationship between DUP and outcome is maintained in the medium-to-long term however remains unclear. We examined the influence of DUP on clinical and functional outcomes in a prospective, naturalistic study of 318 FEP patients followed up 8 years after initial treatment at a specialist early psychosis service. Quality of life, social and occupational functioning, positive and negative symptoms at 8 years were assessed using standardized instruments. Multiple linear regression analyses indicated that, after controlling for the effects of other factors, shorter DUP correlated moderately with decreased severity of positive symptoms, and enhanced social and occupational functioning and quality of life. There was no uniform point associated with medium-to-long term impairment, with some domains of outcome more sensitive to treatment delay than others. However a consistent finding was that outcomes for these domains were significantly worse when DUP exceeded 3 months. Among those with a schizophrenia-spectrum diagnosis, DUP exceeding 1 year was associated with poorer outcome. No association was found between DUP and negative symptoms in either diagnostic group. As with short-term prognosis, DUP appears to be an independent predictor of prognosis in the medium-to-long term. Results support the need for assertive early detection strategies to facilitate the timely delivery of effective intervention programs to those with emerging psychotic illness in order to reduce the risk of long term deleterious outcomes.