Fish Oil for Mental Disorders? My cousin suffers from manic depression. Can fish-oil capsules help her? This is a very hot area of scientific research because fish-oil supplements may reduce the symptoms of manic depression (bipolar disorder) as well as other psychiatric conditions. In manic depression, it's thought that overactive cell signaling in the brain may be at least partly to blame and that omega-3s might curtail the overactivity. A recent study at Harvard Medical School followed 30 otherwise-healthy manic-depressives who were given pills with fish oil which contained omega-3 fatty acids or a placebo (olive oil). Researchers found that the patients taking fish oil were symptom-free for a significantly longer time. The only side effects were mild stomach upset and a "fishy" aftertaste. These findings are preliminary and must be confirmed by further studies, but they do suggest that low levels of essential fatty acids in brain cell membranes may underlie major psychiatric illness. In fact, there's some evidence suggesting that the rising levels of depression in the Western world in recent decades may be related to a low rate of fish consumption. Still, it's not clear how much omega-3 is needed. The Harvard study used a very high dose -- their supplements contained 6.2 grams of one omega-3 fatty acid (eicosapentaoic acid or EPA) and 3.4 grams of another, docosahexanoic acid (DHA). Until we know the most effective dose, I don't recommend that people take fish-oil supplements -- despite this study, it isn't clear if the isolated fish-oil supplements are as beneficial as actually eating fish. (Also, the oils used for commercial capsules may have toxic contaminants.) It would be much better to eat two to three servings of fish per week. Choose fish from cold, northern waters -- sardines, herring, mackerel, and wild salmon (which have much more omega-3 than farmed salmon). And if you are vegetarian (or don't want to eat fish), know that the best source of omega-3s is freshly ground flaxseed. In fact, some of the new omega-3 enriched eggs (available in most parts of the country) come from hens which are fed a special diet comprised of ground flaxseed.