Short duration of untreated psychosis enhances negative symptom remission in extended early intervention service for psychosis.

Abstract

To test whether duration of untreated psychosis (DUP)<3months, recommended by the World Health Organization/International Early Psychosis Association, enhances the effects of an extended early intervention service (EEIS) on symptom remission. We examined data from a randomized controlled trial in which patients who received 2years of treatment in EIS for psychosis were subsequently randomized to either 3years of EEIS or 3years of regular care (RC). Using a DUP cut-off≤12weeks (approximately<3months), patients were split into two groups. Length of positive, negative and total symptom remission were the outcomes. Patients (N=217) were mostly male (68%) with schizophrenia spectrum disorder (65%); 108 (50%) received EEIS (58 had DUP ≤12weeks; 50 had DUP >12weeks). Interaction between treatment condition (EEIS vs. RC) and DUP cut-off≤12weeks was only significant in multiple linear regression model examining length of negative symptom remission as the outcome (adjusted β=36.88 [SE=15.88], t=2.32, P=0.02). EEIS patients with DUP ≤12weeks achieved 25 more weeks of negative symptom remission than EEIS patients with DUP >12weeks. Having a short DUP may be critical in deriving long-term benefits from EIS for psychosis, including EEIS settings. This work empirically supports policy recommendations of reducing DUP <3months.