Duration of untreated psychosis and response to treatment: an analysis of response in the OPTiMiSE cohort.

Some, but not all, studies have found longer duration of untreated psychosis (DUP) to be associated with poor response to treatment and more severe negative symptoms in schizophrenia. The aim of the current analysis was to investigate these parameters in a large cohort of patients in their first psychotic episode. The OPTiMiSE cohort included 446 patients with DUP up to two years, who were administered amisulpride for 4 weeks (Phase I). Patients who did not meet Andreasen remission criteria were randomized to double-blind continuation of amisulpride or olanzapine for 6 additional weeks in a blinded study (Phase II). Analyses showed that shorter DUP was associated with lower baseline CGI scores (p<0.001, r = 0.184), PANSS total (p = 0.025, r = 0.106) and PANSS negative subscale scores (p = 0.023, r = 0.107). Remitters had a significantly shorter mean DUP compared to non-remitters both in Phase I (24.5 weeks ±24.3 vs. 35 weeks ± 32.2, p = 0.01, t=-2.521) and in Phase II (24.3 weeks ± 26.4 vs. 38.3 weeks ± 31.3, p = 0.031, t=-2.194). Logistic regression analyses showed a significant effect of DUP on treatment response both in phase I (p = 0.008) and phase II (p = 0.041). Linear regression analyses found that DUP significantly affects PANSS Total change at the end of phase I (p = 0.028) but not at the end of phase II (p = 0.236). Based on these findings, it is possible to conclude that shorter DUP is associated with better response to treatment, particularly during the first weeks after treatment initiation. These findings highlight the need for early identification of the first psychotic episode.