Predictive factors for antipsychotic treatment adherence among first-episode psychosis patients in the first year after remission

Abstract

Abstract Background: Adherence rates to antipsychotic drugs in schizophrenia are low, while good adherence is important for achieving and maintaining remission. In patients with a ‘First Episode of Psychosis’ (FEP), early medication adherence can influence the further course of the illness. Identification of risk factors for non-adherence to antipsychotics in patients with an FEP in the first year after remission could prove useful. Methods: This study was conducted with patients aged 16 to 55 years old, using antipsychotic medication, and in symptomatic remission of their first psychotic episode for 3-6 months. Medication adherence was determined with the Medication Possession Ratio (MPR) and validated with self-reported adherence rates. Covariate adjustment was performed to determine the influence of overlapping prescriptions on the MPR. The relationship between several patient- and environment-related factors with treatment adherence was assessed with linear regression. Results: A total of 260 patients were included in the MPR calculation, of which 88,8% had a good treatment adherence. The MPR had a very weak correlation with the self-reported adherence rates (p = 0.005). Side effects (p = 0.013) were positively associated with treatment adherence while patients experiencing more self-stigma were less adherent (p = 0.030). Overlapping prescriptions accounted for 25% of the variance in the MPR. After covariate adjustment, only the duration of psychosis was associated with treatment adherence (p = 0.001). Conclusion: The MPR is sensitive to prescribing behavior, therefore correction for overlapping prescriptions is advised. Intervention strategies focused on lowering self-stigma among FEP patients could improve their adherence rates