Effectiveness of antipsychotics used in first-episode psychosis: a naturalistic cohort study.

Background: One year of antipsychotic treatment from symptom remission is recommended following a first episode of psychosis (FEP). Aims: To investigate the effectiveness of commonly used antipsychotic medications in FEP. Method: A retrospective cohort study of naturalistic treatment of patients (N=460) accepted by FEP services across seven UK sites. Treatment initiation to all-cause discontinuation determined from case files. Results: Risk of treatment discontinuation is greatest within 3 months of treatment initiation. Risperidone had longest median survival time. No significant differences were observed in time to discontinuation between commonly used antipsychotics on multivariable Cox regression analysis. Poor adherence and efficacy failure were the most common reasons for discontinuation. Conclusions: Effectiveness differences appear not to be a current reason for antipsychotic choice in FEP. Adherence strategies and weighing up likely adverse effects should be the clinical focus.