ω-3 Fatty acids for major depressive disorder in adults: an abridged Cochrane review.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of randomized controlled trials
PubMed 26936905 · doi:10.1136/bmjopen-2015-010172
What was done
An abridged Cochrane systematic review and meta-analysis searched databases and trial registries up to May 2015 for randomized controlled trials evaluating omega-3 polyunsaturated fatty acid (n-3PUFA) supplementation compared with placebo or active comparators in adults with major depressive disorder (MDD). Primary outcomes assessed were depressive symptomology and adverse events.
What was found
Twenty trials covering 26 studies were included. Compared to placebo, n-3PUFAs showed a small reduction in depressive symptoms (standardized mean difference [SMD] = -0.32, 95% CI -0.52 to -0.12; 25 studies, 1373 participants; very low-quality evidence), with no significant difference in adverse events (OR = 1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence). Compared directly with antidepressants, n-3PUFAs showed no significant difference in depressive symptoms (mean difference [MD] = -0.70, 95% CI -5.88 to 4.48; 1 study, 40 participants; very low-quality evidence).
Why it matters
Despite widespread use, evidence supporting omega-3 supplementation for adult major depressive disorder remains insufficient and unlikely to be clinically meaningful based on existing trial data.
Limits
The entire body of evidence was rated as very low quality. Trials showed substantial unexplained heterogeneity, and funnel plot asymmetry alongside sensitivity analyses indicated a high likelihood of publication and reporting bias. Active comparator data versus standard antidepressants were limited to a single trial of 40 participants.
Cited by
- context Omega-3 fatty acids are equally effective as antidepressants in head-to-head comparisons for depression.