ω-3 Fatty acids for major depressive disorder in adults: an abridged Cochrane review

Katherine M Appleton; Hannah M Sallis; Rachel Perry; Andrew R Ness; Rachel Churchill

doi:10.1136/bmjopen-2015-010172

ω-3 Fatty acids for major depressive disorder in adults: an abridged Cochrane review

BMJ Open. 2016 Mar 2;6(3):e010172. doi: 10.1136/bmjopen-2015-010172.

Authors

Katherine M Appleton¹, Hannah M Sallis², Rachel Perry³, Andrew R Ness³, Rachel Churchill⁴

Affiliations

¹ Department of Psychology, Faculty of Science and Technology, Bournemouth University, Poole, UK.
² Centre for Academic Mental Health, School of Social and Community Medicine, University of Bristol, Bristol, UK MRC Integrative Epidemiology Unit, School of Social and Community Medicine, University of Bristol, Bristol, UK.
³ National Institute for Health Research (NIHR) Biomedical Research Unit in Nutrition, Diet and Lifestyle at the University Hospitals Bristol NHS Foundation Trust and the University of Bristol, Bristol, UK School of Oral and Dental Sciences, University of Bristol, Bristol, UK.
⁴ Centre for Academic Mental Health, School of Social and Community Medicine, University of Bristol, Bristol, UK.

Abstract

Objective: To assess the effects of n-3 polyunsaturated fatty acids (n-3PUFAs; also known as ω-3 fatty acids) compared with comparator for major depressive disorder (MDD) in adults.

Design: Systematic review and meta-analyses.

Data sources: The Cochrane Depression, Anxiety and Neurosis Review Group's Specialised Registers (CCDANCTR) and International Trial Registries searched to May 2015. CINAHL searched to September 2013.

Inclusion criteria: a randomised controlled trial (RCT); that provided n-3PUFAs as an intervention; used a comparator; measured depressive symptomology as an outcome; and was conducted in adults with MDD.

Outcomes: Primary outcomes were depressive symptomology and adverse events.

Results: 20 trials encompassing 26 relevant studies were found. For n-3PUFAs versus placebo, n-3PUFA supplementation resulted in a small-to-modest benefit for depressive symptomology: SMD=-0.32 (95% CI -0.52 to -0.12; 25 studies, 1373 participants, very low-quality evidence), but this effect is unlikely to be clinically meaningful, is very imprecise and, based on funnel plot inspection, sensitivity analyses and comparison with large well-conducted trials, is likely to be biased. Considerable evidence of heterogeneity between studies was also found, and was not explained by subgroup or sensitivity analyses. Numbers of individuals experiencing adverse events were similar in intervention and placebo groups (OR=1.24, 95% CI 0.95 to 1.62; 19 studies, 1207 participants; very low-quality evidence). For n-3PUFAs versus antidepressants, no differences were found between treatments in depressive symptomology (MD=-0.70 (95% CI -5.88 to 4.48); 1 study, 40 participants, very low-quality evidence).

Conclusions: At present, we do not have sufficient evidence to determine the effects of n-3PUFAs as a treatment for MDD. Further research in the form of adequately powered RCTs is needed.

Keywords: EPIDEMIOLOGY; NUTRITION & DIETETICS; THERAPEUTICS.

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Publication types

Comparative Study
Research Support, Non-U.S. Gov't
Review
Systematic Review

MeSH terms

Adult
Antidepressive Agents / therapeutic use*
Depressive Disorder, Major / drug therapy*
Fatty Acids, Omega-3 / therapeutic use*
Humans
Treatment Outcome

Substances

Antidepressive Agents
Fatty Acids, Omega-3