Fish oils may prevent some forms of depression

A study, led by King’s College London, has found that omega-3 fatty acids reduce the rates of depression among patients with high levels of inflammation. Patients with increased inflammation have a greatly increased risk of depression. The study involved patients who were receiving medical treatment (interferon-alpha therapy) over 6 months for chronic hepatitis C.
Approximately 30% of patients receiving this type of treatment become depressed, and it is a commonly-used model of inflammation-induced depression. Omega-3 fatty acids, more commonly known as fish oils, have a long list of health benefits, including lowering the risk of heart disease and reducing triglyceride levels. Omega-3s are of high interest to the depression field, where several studies have suggested benefits for depression and other psychiatric disorders. The two main omega-3 fatty acids in fish oil supplements are EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid).
In the study, 152 patients with hepatitis C were randomised to receive two weeks of treatment with EPA, DHA, or placebo. Following the two-week treatment, the patients received a 24-week course of interferon-alpha treatment and were evaluated repeatedly for depression. The researchers found that treatment with EPA, but not DHA or placebo, decreased the incidence of interferon-alpha-induced depression in patients being treated for hepatitis C. In addition, both EPA and DHA delayed the onset of depression, and both treatments were well tolerated, with no serious side effects.