The long-chain omega-3 polyunsaturated fatty acids (LC-PUFA) have been shown to play a fundamental role in brain structure and function. Many studies indicate a link between adequate intake of LC-PUFA and lower incidence of depression.
Omega-3 polyunsaturated fatty acids from fish oil showed significant anti-depressant effect in 10 double-blind, placebo controlled studies in patients with mood disorders.
Countries whose citizens consume greater amounts of seafood and fish oil rich in omega-3 fatty acids seem to have lower prevalence of depression, post-partum depression and seasonal affective disorder.
Omega-3 fatty acids were well tolerated and improved the short-term course of illness in preliminary study of patients with bipolar disorder. These are the results from the famous bipolar disorder trial by Dr. Andrew Stoll.