Omega-3 fatty acids (fish-oil) and depression-related cognition in healthy volunteers

Omega-3 polyunsaturated fatty acid (n-3 PUFA) supplementation may be beneficial in the treatment of several psychiatric disorders, including depression. A small number of studies have suggested that there may also be cognitive and mood effects in healthy samples. The purpose of the present study was to investigate the effects of n-3 PUFA on depression-relevant cognitive functioning in healthy individuals. Fifty-four healthy university students were randomized to receive either n-3 PUFA supplements or placebo for 4 weeks in a double-blind design. The test battery included measures of cognitive reactivity, attention, response inhibition, facial emotion recognition, memory and risky decision-making. Results showed few effects of n-3 PUFAs on cognition and mood states. The n-3 PUFA group made fewer risk-averse decisions than the placebo group. This difference appeared only in non-normative trials of the decision-making test, and was not accompanied by increased impulsiveness. N-3 PUFAs improved scores on the control/perfectionism scale of the cognitive reactivity measure. No effects were found on the other cognitive tasks and no consistent effects on mood were observed. The present findings indicate that n-3 PUFA supplementation may have a selective effect on risky decision making in healthy volunteers, which is unrelated to impulsiveness.