EPA and DHA as markers of nutraceutical treatment response in major depressive disorder

Purpose: Depression clinical trials are increasingly studying biomarkers to predict and monitor response to treatment. Assessment of biomarkers may reveal subsets of patients who are responsive to nutraceutical treatment, which may facilitate a personalized approach to treating depression. Methods: This is a post hoc analysis of an 8-week, double-blind, randomized, controlled trial (n = 158) investigating a combination nutraceutical comprising Omega-3 (EPA 1 g/DHA 656 mg), SAMe, zinc, 5-HTP, folinic acid, and co-factors versus placebo for the treatment of Major Depressive Disorder. The study explored levels of polyunsaturated fatty acids, folate, vitamin B12, zinc, homocysteine, and BDNF as possible predictors and correlates of response to nutraceutical supplementation. Results: Concentrations of EPA and DHA in red cell membranes increased in response to treatment and were significantly correlated with a decrease in depressive symptoms during active treatment (p = 0.003 and p = 0.029; respectively). Higher baseline levels of omega-6 fatty acid also correlated with depression reduction in the active treatment group (p = 0.011). No other biomarkers were associated with a lessening of depressive symptoms. Conclusion: Changes in fatty acid levels resulting from a nutraceutical combination containing EPA and DHA provide a response biomarker in treating depression.