Prevalence and risk factors of non-adherence to antipsychotic medications in Saudi Arabia.

Purpose: To evaluate the rate and determinants of non-adherence to antipsychotic medications in Saudi Arabia.

Materials and methods: This was a cross-sectional study that included a questionnaire, interview, and data extraction from medical records of adult patients on antipsychotic medications. The study was conducted at outpatient clinics at the psychological care department at King Fahad Medical City, Riyadh, Saudi Arabia, between October 25 and November 26, 2020. Data collection included three parts: patients' sociodemographic characteristics; antipsychotic medications used and patients' clinical characteristics; and adherence to antipsychotic medications measured by the Medication Adherence Rating Scale (MARS).

Results: Out of 220 patients, 122 (55.5%) were considered non-adherent (MARS scores 6 or less). The MARS items contributing most to non-adherence were "the medication makes me feel tired and sluggish" and "forget to take the medication", 55 and 40.9%, respectively. Additionally, adverse drug effect significantly increased the risk of poor adherence in regression analysis (odds ratio = 1.97, p = 0.028). The model also showed that female sex, low income, cigarette smoking, substance abuse, uncontrolled disease, comorbidity, and use of Ruqyah religious therapy were associated with increased risk of poor adherence, but were however not statistically significant (p < 0.05).

Conclusion: This study showed high non-adherence rate to antipsychotic medications. Adverse drug effects and forgetting to take medications were the main patient-reported barriers to adherence. Likewise, sociodemographic, clinical, and spiritual factors affected medication adherence. Knowing these predictors helps in early identification of patients who are predisposed to medication non-adherence and allows personalized interventions that improve adherence and treatment outcomes.