The purpose of this review was to examine the current level of evidence regarding the efficacy of omega-3 fatty acid supplementation in improving bipolar disorder symptoms.

Of 99 articles meeting initial search criteria, 5 randomized control trials and 2 quasi-experimental studies were selected for review.

Omega-3 fatty acid supplementation was effective in 4 of 7 studies. Those using an omega-3 combination of eicosapentaenoic acid and docosahexanoic acid demonstrated a statistically significant improvement in bipolar symptoms, whereas those using a single constituent did not. Dosage variations did not demonstrate statistically significant differences.

Due to its benign side effect profile and some evidence supporting its usefulness in bipolar illness, omega-3 may be a helpful adjunct in treatment of selected patients. Future studies are needed to conclusively confirm the efficacy of omega-3s in bipolar disorder, uncovering a new well-tolerated treatment option.