Long-acting antipsychotic medication as first-line treatment of first-episode psychosis with comorbid substance use disorder

Aim: Substance use disorder (SUD) is highly prevalent among patients with first-episode psychosis (FEP) and associated with poor adherence and worst treatment outcomes. Although relapses are frequent in FEP, current literature on long-acting injectable antipsychotics (LAI-AP) use in FEP is scarce and studies often exclude patients with SUD. Objectives: To determine the impact of LAI-AP as first-line treatment on psychotic relapses or rehospitalizations in FEP patients with comorbid SUD (FEP-SUD). Methods: This is a naturalistic, longitudinal, 3-year prospective and retrospective study on 237 FEP-SUD admitted in two EIS in Montreal, between 2005 and 2012. The patients were divided on the basis of first-line medication introduced, either oral antipsychotics (OAP, n = 206) or LAI-AP (n = 31). Baseline characteristics were compared using χ² test and analysis of variance, and Kaplan-Meier survival analysis was performed on relapse and rehospitalization. Results: Compared to the OAP group, patients in the LAI-AP group presented worse prognostic factors (eg, history of homelessness). Despite this, the LAI-AP group presented a lower relapse rate (67.7% vs 76.7%), higher relapse-free survival time (694 vs 447 days, P = 0.008 in Kaplan-Meier analysis), and trends for reduced rehospitalization rates (48.4% vs 57.3%) and hospitalization-free survival time (813 vs 619 days, P = 0.065 Kaplan-Meier analysis). Of those receiving OAP as first-line, 41.3% were eventually switched to LAI-AP and displayed worst outcome in relapse and rehospitalization. Conclusion: LAI-AP should be strongly considered as first-line treatment of FEP-SUD patients since this pharmacological option reduces the risk of relapse and rehospitalization even in the individuals with poor prognostic factors.