Comparative Efficacy Of Exercise Training And Conventional Behavioral Therapies For Depression: A Network Meta-analysis

Abstract

PURPOSE: According to the World Health Organization (2018), depressive disorders affect over 300 million individuals worldwide. Exercise training (ET) shows promise as a therapy for depression, but there lacks evidence of its efficacy compared to conventional behavioral therapies. This Network Meta-Analysis (NMA) compares the efficacy of 3 evidenced-based therapies for depressive disorders and ET to assess ET as a potential evidence-based therapy for adults with depression. METHODS: A medical librarian conducted a literature search of the following databases from inception to March 10, 2020: PubMed (NLM), Embase (Elsevier), Scopus (Elsevier), Cochrane Central (Wiley), PsycInfo (EbscoHost), ClinicalTrials.gov, and PsychiatryOnline.org. Randomized controlled trials (RCTs) were included if they compared ET to cognitive behavioral therapy (CBT), behavioral activation therapy (BAT), non-directive supportive therapy (ST) and/or to waitlist (WL) or treatment as usual (TAU) for depressive disorders in adults. Primary outcomes were efficacy (i.e., change in depressive symptoms) using standardized mean differences (SMDs). RESULTS: From 28,716 studies, we included 134 RCTs (N = 14,812). All 4 behavioral interventions were superior to TAU (SMD range, -0.49 to -0.95) and WL (SMD range, -0.80 to -1.26) control conditions. In terms of efficacy, both BAT (-0.22; -0.68 to 0.24) and CBT (-0.12; -0.42 to 0.17) were slightly more efficacious than ET with ST slightly less efficacious (0.24; -0.25 to 0.73). Overall, these effect sizes are at or below the suggested cut-off of 0.24, which suggests a minimally important clinical difference. Heterogeneity estimates using a common estimate showed significant inconsistency in 1 of the 10 loops indicating that only one loop had significant differences between direct and indirect estimates. Loop-specific estimates, however, suggested that none of the loops had significant heterogeneity. BAT had the highest mean ranking (1.6) followed by CBT (1.9), ET (2.8), and ST (3.8). CONCLUSION: Findings suggest that ET, CBT, BAT, and ST have comparable efficacy as therapies for depression. Our findings support exercise as an evidence-based therapy for adults with depression. This has important implications for clinicians when discussing therapy options with patients.