Association between polypharmacy and depression: a systematic review and meta‐analysis

Aims Polypharmacy is associated with multiple adverse health outcomes. The objective of this systematic review and meta‐analysis was to explore the association between polypharmacy and depression. Methods and results A systematic literature review was conducted by searching MEDLINE, Scopus, Science Direct, and CINAHL Complete to identify studies assessing the association between polypharmacy and depression published until November 2020. A meta‐analysis was performed using random effect models. Heterogeneity was assessed using the I 2 ‐statistic. Nineteen studies were included in the meta‐analysis. We found that an increase in the number of drugs was associated with an increased risk of depression (OR = 1.55 [95% CI: 1.01, 2.36; I 2 = 62%, n = 2]). Further, polypharmacy defined as the concurrent use of five or more medications was associated with an increased risk of depression (OR = 1.73 [95% CI: 1.39, 2.14], I 2 = 83%, n = 8). Conclusion This meta‐analysis revealed that polypharmacy, both discretely and categorically defined, was associated with an increased risk of depression.