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Effect of Long-term Supplementation With Marine Omega-3 Fatty Acids vs Placebo on Risk of Depression or Clinically Relevant Depressive Symptoms and on Change in Mood Scores: A Randomized Clinical Trial

O. Okereke, Chirag M. Vyas, D. Mischoulon, G. Chang, N. Cook, Alison Weinberg, V. Bubes, Trisha Copeland et al.

Journal of the American Medical Association (JAMA), 2021

25 participants · 108 citations

Abstract

Importance

Marine omega-3 fatty acid (omega-3) supplements have been used to treat depression but their ability to prevent depression in the general adult population is unknown.

Objective

To test effects of omega-3 supplementation on late-life depression risk and mood scores.

Design, Setting, and Participants

A total of 18 353 adults participated in the VITAL-DEP (Vitamin D and Omega-3 Trial-Depression Endpoint Prevention) ancillary study to VITAL, a randomized trial of cardiovascular disease and cancer prevention among 25 871 US adults. There were 16 657 at risk of incident depression (no previous depression) and 1696 at risk of recurrent depression (previous depression, but not for the past 2 years). Randomization occurred from November 2011 through March 2014; randomized treatment ended on December 31, 2017.

Interventions

Randomized 2 × 2 factorial assignment to vitamin D3 (2000 IU/d), marine omega-3 fatty acids (1 g/d of fish oil, including 465 mg of eicosapentaenoic acid and 375 mg of docosahexaenoic acid) or placebo; 9171 were randomized to omega-3 and 9182 were randomized to matching placebo.

Main Outcomes and Measures

Prespecified coprimary outcomes were risk of depression or clinically relevant depressive symptoms (total of incident + recurrent cases); mean difference in mood score (8-item Patient Health Questionnaire [PHQ-8] depression scale).

Results

Among 18 353 participants who were randomized (mean age, 67.5 [SD, 7.1] years; 49.2% women), 90.3% completed the…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 3 of 5 (Moderate · trial / cohort / secondary analysis). Trials without a large randomized design, cohorts and secondary analyses give moderate evidence. Reported size: 25 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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