The effects of statin monotherapy on depressive symptoms: A systematic review and meta-analysis

Introduction: Statins have been proposed as a strategy for treating depression, but their benefit in the absence of concurrent antidepressant treatment is unclear. This meta-analysis investigated the antidepressant effects of statin monotherapy in the general population. Methods: We conducted a literature search of randomised controlled trials using any statin monotherapy versus any control condition for depressive symptoms. Our primary efficacy outcome was the mean value on any standardised scale for depression at study endpoint. We also measured efficacy at three further timepoints (< 6 months, 6-12 months, > 12 months), as well as acceptability, tolerability, and safety. Respectively, continuous and dichotomous outcomes were computed using standardised mean difference (SMD) or relative risk (RR) with 95% confidence intervals (CI) using a random-effect model. Results: Pooled analyses did not show that statin monotherapy improves depressive symptoms at endpoint (N = 2712 SMD =-0.18; 95% CI =-0.41 to 0.04), nor at any other specific timepoint. No difference between statins and control was identified for any of the other outcome measures. Discussion: These results differ from those of previous meta-analyses and, compounded by more recently available evidence, suggest that statins may not have intrinsic antidepressant properties, but may be useful for the management of depression in add-on to antidepressants. Limitations: Data from heterogeneous populations and using different statins were pooled, though several sensitivity and subgroup analyses were performed to account for that.