Although current data support supplementation with omega-3 fatty acids as part of treatment for symptoms of depression, there is insufficient evidence to conclude whether supplementation is useful for patients with bipolar disorder, according to a review in Issue 2 (2008) of the Cochrane Database of Systematic Reviews.

Nevertheless, omega-3 supplementation deserve further study because it seems to have no serious side effects and most experts recommend supplements for people with heart disease and some immune disorders, said authors Paul Montgomery, PhD, and Alex Richardson, PhD, study authors and faculty at the University of Oxford, U.K.

Montgomery and Richardson found five studies on the effects of omega-3 supplements for bipolar disorder, but only one study of 75 patients provided enough data on outcomes for the researchers to analyze. Patients had less severe depression symptoms while taking the supplements, but supplementation did not affect symptoms associated with mania.

Montgomery said the review makes it clear that there is not enough evidence yet to determine how omega-3 supplementation affects symptoms of bipolar disorder, "and what evidence is currently available is of such a varied and oftentimes questionable nature that no reliable conclusions may be drawn."

Recently, a growing handful of studies have suggested that omega-3 fatty acid supplementation can be beneficial for other mood disturbance disorders such as clinical depression, personality disorders and schizophrenia

Different versions of the fatty acids are in vegetable oils such as flax seed oil and in fish oils. Researchers are still not clear how the fatty acids work in the body, but they might "play key roles in brain structure and function," Montgomery said.

For the moment, the few studies available suggest that patients should use a supplement together with prescribed mood stabilizers, Montgomery said.
Joseph Hibbeln, MD, who heads the nutritional neurochemistry division of the National Institute on Alcohol Abuse and Alcoholism, said he and his colleagues "strongly recommend" that patients with psychiatric disorders not take omega-3 supplements "in lieu of established psychiatric treatment options."