Purpose of review: To overview the theoretical relevance of omega-3 and omega-6 fatty acids in the cause of mood disorders, and focus on evaluating the potential therapeutic role of omega-3 fatty acids.
Recent findings: Numerous studies have documented low omega-3 fatty acid levels in those with depressive disorders, and there are plausible biological explanations as to why reduced omega-3 status may predispose to mood disorders as well as to a range of other conditions. Although early studies evaluating the role of omega-3 preparations as treatments of depression were generally positive, the rate of negative or nondifferential studies has increased in recent years. Recent meta-analyses provide an explanation in suggesting that docosahexaenoic acid-weighted preparations may be ineffective while finding support for eicosapentaenoic acid (EPA)-weighted preparations.
Summary: There is sufficient indicative data favouring EPA-weighted omega-3 supplementation for those with a depressive mood disorder, particular when fish oil is viewed by patients as 'natural,' it has few side effects and is neuroprotective. Recent meta-analyses inform us that intervention studies should focus on EPA-weighted preparations.