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