Omega-3 fatty acids for bipolar disorder

A Cochrane systematic review investigated the efficacy of omega-3 fatty acids for bipolar disorder. Only one trial out of 5 provided data that could be analysed, investigating ethyl-EPA(=eicosapentaenoic acid) as an adjunctive treatment in a mixed outpatient population. Some positive benefits were found for depressive symptoms but not for mania, and no adverse events were reported.

There is currently insufficient evidence on which to base any clear recommendations concerning omega-3 fatty acids for bipolar disorder. However, given the general health benefits and safety of omega-3, the preliminary evidence from this review provides a strong case for well-powered, high-quality trials in specific index populations.

What are omega-3 fatty acids?
From Medscape

the essential fatty acids omega-3 and omega-6 are taken in through diet and compete with each other for the same elongation enzymes. Omega-6 eventually leads to arachidonic acid and eicosanoids, which promote inflammation, platelet clotting, and the production of prostaglandins. Omega-3 also leads to the production of eicosanoids, but the eicosanoids that are derived from omega-3 — eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — actually possess anti-inflammatory properties and decrease platelet stickiness.

These two main omega-3 fatty acids in fish oil have important biological functions in the brain. DHA is a component of neuronal membranes, and changing the fatty acid composition of neuronal membranes leads to functional changes in the activity of receptors and other proteins embedded in the neuronal membranes. This is why researchers got interested in the use of omega-3 fatty acids in all kinds of psychiatric disorders, also in bipolar disorder. Stabilizing the membrane could possibly mean also stabilizing mood.

The only study used in this review was a 12 week, double-blind, randomised trial with 3 conditions.
Active treatment, receiving a total of 1g/day of EPA, active treatment, receiving a total of 2g/day of EPA, or control treatment, receiving a total of 2g/day of a placebo (liquid paraffin). There was no significant difference between 1 or 2 grams of EPA a day, the groups were combined for analysis.All participants were allowed to continue all associated psychotropic medication during the trial. Participants were recruited on the referral of their treating physicians or through advertisements in patient groups’ newsletters. 75 Patients participated which is a small group.

My opinion is that it is to early to speak of an additional effect, on the other hand no adverse effects were found.

Food rich in omega-3 fatty acids (thanks WHFoods)
Montgomery, P., Richardson, A., Montgomery, P. (2008). Omega-3 fatty acids for bipolar disorder. DOI: 10.1002/14651858.CD005169.pub2