Association Between Depression and Medication Adherence Among Post-myocardial Infarction Patients in a South Asian Clinical Setting

BACKGROUND: Medication adherence is vital for successful recovery after a myocardial infarction (MI). Unfortunately, many patients experience depression following an MI, which can negatively affect their ability to stick to prescribed medication plans. It is important to explore how depression influences medication adherence, especially in South Asian clinical environments where cultural factors can significantly impact health outcomes. METHODS: A cross-sectional study was carried out among 385 post-MI patients who attended outpatient clinics in Islamabad, Pakistan. The Patient Health Questionnaire-9 (PHQ-9) was used to measure depression, and the Morisky Medication Adherence Scale (MMAS-8) was used to quantify medication adherence. Statistical tests involved descriptive statistics, normality tests using Shapiro-Wilk, Spearman correlation, Kruskal-Wallis, chi-square, and linear regression. Data were collected between January and May 2025. RESULTS: There was also a weak, statistically significant positive relation between the PHQ-9 and the MMAS-8 scores (r = 0.124, p < 0.05). In a linear regression model, PHQ-9 scores were significantly predictive of MMAS-8 scores (B = 0.064, p = 0.002), which means that the higher the depressive symptoms, the more likely medication adherence was. Depression scores worsened over time since MI and heavier medication burden, whereas adherence was highest among patients taking moderate numbers of medications (three to five/day). The rates of adherence and psychological distress also differed significantly depending on the treatment type, with the best rates being in angioplasty patients. CONCLUSION: This study, unlike the majority of the previous findings, reported a minor positive correlation between self-reported medication adherence and depressive symptoms in post-MI patients. The findings indicate that, in particular, in the cultural backdrop, depressive symptoms can be present alongside more health conscientiousness or planned-out care use. Comorbidities and complexities of treatment should be assessed, and mental health screening and adherence support to medications should be a component of post-MI care strategies.