Medication Non-adherence in Schizophrenia and Bipolar Affective Disorder: A Cross-sectional Study from Two Tertiary Hospitals in South-South Nigeria

Abstract

Background: Symptoms remission and significant improvements in functionality is predicated on good medication adherence. Non-adherence to medication in persons with bipolar disorder and schizophrenia is the main reason for frequent relapses and poor treatment outcomes. Aims: This study was conducted to determine the prevalence of medication non-adherence in persons with schizophrenia and bipolar affective disorder and identify factors related to it. Methods: This was a cross-sectional study conducted on a sample of outpatients with schizophrenia and bipolar affective disorder. One hundred and seventy two participants were enrolled into the studies from March to June 2025.  Medication adherence was assessed on the basis of patients’ self-reports. Socio-demographic and selected clinical variables were collected and compared between adherent and non-adherent participants. Logistic regression analysis was done to determine predictors of treatment non-adherence. Results: The mean age was 35.47±10.6, and 47.7% of participants were males. 56.4% of the subjects were adherent to medication. Factors that independently predicted non adherence to treatment on multivariate analysis were: high cost of medication (OR=3.46, P=.005), non availability of supervised treatment (OR=0.159, P=.06) high dosing frequency of medication (OR=3.33,P=<.003), side effects profile (OR=0.10,P=.05) high pill burden (OR=1.13, P=.04) and a poor attitude to medication (OR=0.47,P=.005) Conclusion: A high prevalence of medication non-adherence was found amongst outpatients with schizophrenia and bipolar disorders in mental health services in South-South Nigeria. Interventional strategies are required to improve adherence to medication in these patients.