Despite intriguing findings that omega-3 fatty acid supplements could alleviate depression symptoms, there is still not enough evidence to say whether omega-3s are useful treatments for people with bipolar disorder, according to a review of recent studies.
Nevertheless, omega-3s deserve further study, since they seem to have no serious side effects and most experts recommend the supplements for people with heart disease and some immune disorders, said authors Paul Montgomery, Ph.D., and Alex Richardson, Ph.D., of the University of Oxford.
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 the therapy’s outcomes for the researchers to analyze. Patients in the study had less severe depression symptoms while taking the supplements, but omega-3s did not affect their mania symptoms. Patients with bipolar disorder can cycle between periods of mania elevated mood and energy and depression.
The review of studies appears in the latest issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews like this one draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
Montgomery said the review makes it clear that there is not enough evidence yet to determine how omega-3s affect bipolar disorder, "and what evidence is currently available is of such a varied and oftentimes questionable nature that no reliable conclusions may be drawn."
Bipolar disorder is among the top 30 causes of disability worldwide. Clinicians prescribe a variety of mood-stabilizing drugs to treat the complex psychiatric disorder, but the medications rarely cause symptoms to disappear completely and they can have serious side effects.
Recently, a growing handful of studies have suggested that omega-3s 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 omega-3s 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 omega-3s along with prescribed mood stabilizers, Montgomery said.
Joseph Hibbeln, M.D., 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."
Companies that manufacture the supplements, along with government and charity funding, supported some of the studies considered for the review. Montgomery and Richardson have worked as consultants to several fatty acid supplement companies, the review disclosed.
Montgomery P, Richardson AJ. Omega-3 fatty acids for bipolar disorder. The Cochrane Database of Systematic Reviews 2008, Issue 2.
The Cochrane Collaboration is an international nonprofit, independent organization that produces and disseminates systematic reviews of health care interventions and promotes the search for evidence in the form of clinical trials and other studies of interventions. Visit http://www.cochrane.org for more information.