Many people take fish oil supplements in an effort to boost their mood and ease symptoms of depression. Typically made from fatty fish like salmon and mackerel, fish oil supplements are rich in omega-3 fatty acids called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Known to help regulate brain function, DHA and EPA are often found at low levels in people with depression.
Research on Fish Oil for Depression
The National Institutes of Health (NIH) classify fish oil as "possibly effective" as treatment of depression. Indeed, a 2009 report published in The Journal of Clinical Psychiatry found that adding fish oil supplements to standard care appears to benefit people with major depression. However, the report's authors caution that more research is needed before fish oil supplements can be recommended as a sole treatment for major depression.
In another 2009 report, published in the Journal of the American College of Nutrition, investigators reviewed 28 studies and found that use of fish oil supplements was linked to significant improvement in major depression and bipolar disorder (but not in mild-to-moderate depression). The review also revealed that omega-3 supplements were more effective as a depression therapy (as opposed to a depression prevention strategy), and that EPA may be more effective than DHA in treating depression.
Other research suggests that fish oil may help treat depression related to specific health issues. For instance, in a 2009 study from the American Journal of Clinical Nutrition, scientists discovered that taking EPA supplements for eight weeks helped lessen depressive symptoms among women undergoing menopause.
It should be noted that several studies have also found that fish oil failed to fight depression. In a 2005 report from the journal Prostaglandins, Leukotrienes, and Essential Fatty Acids, for instance, patients who added fish oil supplements to their standard depression treatment experienced no greater mood-related benefits (compared to patients given a placebo supplement containing olive oil).
When left untreated, depression can lead to a number of serious problems (including alcohol abuse and heart disease). Therefore, it's important to work closely with a mental-health professional rather than using fish oil (or any other natural remedy or alternative therapy) to self-treat depression. In no case should fish oil be considered a substitute for medical treatment of depression (or any other mood disorder).
Although fish oil is likely safe for most people, it can cause certain adverse effects (such as increased cholesterol levels) when taken in large amounts. Fish oil may also interact with some medications (including birth control pills and medications for high blood pressure) and herbs and supplements that can slow blood clotting (including garlic, ginger, and ginkgo biloba).
Using Fish Oil for Depression
Increasing your consumption of oily fish (including sardines, herring, and tuna, in addition to salmon and mackerel) can boost your omega-3 intake and possibly protect against depression. If you're not eating at least four servings of oily fish per week, talk to your doctor about using fish oil supplements to help prevent or manage depression.
Ali S, Garg SK, Cohen BE, Bhave P, Harris WS, Whooley MA. "Association between omega-3 fatty acids and depressive symptoms among patients with established coronary artery disease: data from the Heart and Soul Study." Psychother Psychosom. 2009;78(2):125-7.
Freeman MP. "Omega-3 fatty acids in major depressive disorder." J Clin Psychiatry. 2009;70 Suppl 5:7-11.
Lucas M, Asselin G, Mérette C, Poulin MJ, Dodin S. "Ethyl-eicosapentaenoic acid for the treatment of psychological distress and depressive symptoms in middle-aged women: a double-blind, placebo-controlled, randomized clinical trial." Am J Clin Nutr. 2009 Feb;89(2):641-51.
Martins JG. "EPA but not DHA appears to be responsible for the efficacy of omega-3 long chain polyunsaturated fatty acid supplementation in depression: evidence from a meta-analysis of randomized controlled trials." J Am Coll Nutr. 2009 Oct;28(5):525-42.
National Institutes of Health. "Fish oil: MedlinePlus Supplements". September 2010.
Silvers KM, Woolley CC, Hamilton FC, Watts PM, Watson RA. "Randomised double-blind placebo-controlled trial of fish oil in the treatment of depression." Prostaglandins Leukot Essent Fatty Acids. 2005 Mar;72(3):211-8.