From the Guidelines
Fish oil supplements containing omega-3 fatty acids, particularly those with high EPA content, may be considered as an adjunctive treatment for depression symptoms, but should not replace conventional treatments. The most recent and highest quality study, a systematic review and network meta-analysis published in 2023 in the Annals of Internal Medicine 1, found that nonpharmacologic treatments, including omega-3 fatty acids, had similar benefits to second-generation antidepressants as first-step treatments for major depressive disorder (MDD). However, the certainty of evidence for most comparisons is low, and findings should be interpreted cautiously.
Key points to consider when using omega-3 fatty acids for depression symptoms include:
- EPA (eicosapentaenoic acid) is more effective than DHA (docosahexaenoic acid) 1
- Supplements containing at least 60% EPA may show better results
- A typical recommended dosage is 1-2 grams daily of an omega-3 supplement with high EPA content
- Benefits typically emerge after 4-8 weeks of consistent use
- Side effects are generally mild and may include fishy aftertaste, bad breath, heartburn, or nausea
- People taking blood thinners should consult their doctor before starting omega-3 supplements due to potential increased bleeding risk
It is essential to note that omega-3 fatty acids should be used in conjunction with standard treatments like antidepressants and psychotherapy, rather than as a standalone solution for clinical depression. The International Society for Nutritional Psychiatry Research practice guidelines for omega-3 fatty acids in the treatment of MDD, published in 2019 in Psychotherapy and Psychosomatics 1, provide further guidance on the use of omega-3 fatty acids in depression treatment.
From the Research
Evidence for Using Fish Oils or Omega 3 Fatty Acids for Symptoms of Depression
- The use of omega-3 fatty acids, particularly those found in fish and seafood, has been studied as a potential adjunctive treatment for major depressive disorder 2.
- Studies have shown that omega-3 fatty acids may have antidepressant effects, although results are mixed and more research is needed to fully understand their efficacy 2, 3, 4, 5.
- Some studies have found significant benefits of omega-3 fatty acid supplementation in reducing depressive symptoms, including a study that found highly significant benefits of eicosapentaenoic acid (EPA) treatment compared to placebo in adult unipolar depression 3.
- However, other studies have found no significant differences between omega-3 fatty acid supplementation and placebo, including a randomized double-blind placebo-controlled trial that found no additional benefit of tuna fish oil supplementation compared to conventional treatment for major depression 6.
- The existing body of evidence suggests that omega-3 fatty acids, particularly EPA and docosahexaenoic acid (DHA), may have antidepressant effects due to their modulation of neuroinflammation, neurotransmitter function, and neuroplasticity 5.
- Factors such as dosage, the ratio of EPA to DHA, and baseline nutritional status may impact the results of omega-3 supplementation studies, and further research is needed to establish uniform guidelines for their use in the management of depressive disorders 5.