Omega-3 supplementation may help decrease the depressive symptoms, researchers report in the Journal of Clinical Psychiatry.

Examples of omega-3 fatty acids include docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), and alpha-linolenic acid (ALA). Dietary sources of omega-3 fatty acids include fish oil and certain plant/nut oils.

The Canadian study included 432 adults who had been experiencing major depressive episodes for at least four weeks. About 40 percent of the patients were taking antidepressant medications at the beginning of the study.

The participants were randomly assigned to take either 1.05 grams of EPA plus 150 milligrams of DHA or a sunflower oil placebo containing two percent fish oil daily for eight weeks.

Overall, both groups experienced similar reductions in self-reported depression symptoms and clinician-rated depression scores.

However, a beneficial effect was observed in a subgroup of 204 patients who did not have any additional anxiety disorders. In this subgroup, patients who took omega-3 supplements experienced significant improvements in both self-reported depression symptoms and clinician-rated depression scores compared to those who took placebo.

Additional research is needed to confirm these findings. Earlier studies have reported conflicting results on the effects of omega-3 fatty acids on depression.

In the United States, EPA and DHA are commonly used to help lower triglycerides and reduce the risk of heart disease.

For more information about EPA or DHA, please visit Natural Standard's Foods, Herbs & Supplements database.

1. Lespérance F, Frasure-Smith N, St-André E, et al. The efficacy of omega-3 supplementation for major depression: a randomized controlled trial. J Clin Psychiatry. 2010 Jun 15. View Abstract
2. Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com