The N-3 polyunsaturated fatty acids supplementation to prevent depression recurrence in patients with late-life depression: A 52-week double-blind, placebo-controlled trial

Background: Reports on the efficacy of omega-3 fatty acids (n-3 PUFAs) for the treatment of late-life depression (LLD) are mixed, and most studies focus on the modification of depressive symptoms rather than depression prevention. The aim of the present study was to investigate the efficacy of n-3 PUFAs in preventing depressive recurrence in patients with late-life depression. In addition, we investigated the effects of n-3 PUFAs on changes in depressive and anxiety symptoms and inflammatory markers in LLD. Methods: A 52-week, double-blind, randomized, controlled trial was conducted. We enrolled a total of 39 euthymic patients with LLD. They were randomized to receive either n-3 PUFAs (1.2 g per day of eicosapentaenoic acid and 1 g of docosahexaenoic acid) or placebo for 52 weeks. Recurrence of depression and severity of depression symptoms were assessed at baseline and weeks 4, 8, 16, 24, 32, 40, and 52. Results: A total of 39 patients completed the trial with 19 in the n-3 PUFAs group and 20 in the placebo group. Cox proportional hazard regression indicated that n-3 PUFAs had significant protective effect on depression recurrence (Hazard Ratio: 0.295, 95 % Confidence Interval: 0.093-0.931, p value =0.037). But n-3 PUFAs intervention had no significant effect in reducing depressive or anxiety symptoms, inflammatory markers over the placebo group. Limitation: The results should be interpreted with consideration of the modest sample size. Conclusion: These findings suggest that n-3 PUFAs may have a prophylactic effect in currently euthymic patients with LLD.