A recent double-blind, placebo-controlled trial of 30 patients with bipolar affective disorder demonstrated a significant benefit of ω3 fatty acid supplements on reducing episodes of severe mania and depression.1 ω3 Polyunsaturated fatty acids (PUFAs) are now regarded as a promising but untested treatment as mood stabilizers.2 Consistent with these observations, several studies of patients with depression have reported depletions of ω3 PUFAs in plasma or cell membranes.3 Previously, a cross-national comparison revealed a 50-fold lower annual prevalence of major depression, which was strongly predicted by higher fish consumption.4 Since fish is the major source of ω3 fatty acids in the human diet, the frequent consumption of fish could lead to a high intake of ω3 PUFAs, thus decreasing the risk of depression.
Tanskanen A, Hibbeln JR, Hintikka J, Haatainen K, Honkalampi K, Viinamäki H. Fish Consumption, Depression, and Suicidality in a General Population. Arch Gen Psychiatry. 2001;58(5):512–513. doi: