In that certain previous studies have suggested a link between omega-3 fatty acids and mood, Yaser Tajalizadekhoob, from Tehran University of Medical Sciences (Iran ), and colleagues have elucidated on the biological basis supporting the association. The team enrolled 66 men  and women, ages 65 years and over, in a six-month long study. Each subject received either an omega-3 supplement – containing one gram of fish oil per day, providing 300 mg of both EPA and DHA – or placebo, daily.  The researchers report  that: “After adjusting for cholesterol, [body mass index], and history of thyroid dysfunctions, a statistically significant difference was seen in scores [on a standardized depression test for seniors] between both groups. Furthermore, treatment with [omega-3 fatty acids] was clinically more effective in treating depression in comparison with the placebo.”  The team concludes that: Low-dose [omega-3 fatty acids] had some efficacy in the treatment of mild to moderate depression in elderly participants.”