Nutritional antidepressants

Nutrition has been implicated as one of the causes and risk factors for depression, and accordingly, one approach to depression involves the use of nutritional supplements or changes in diet. A study of older adults found that poor nutrition was a strong predictor of depressive symptoms a year later. A few nutrients have been studied directly for their antidepressant properties, both to treat and prevent depression, as well as related conditions such as anxiety.

Omega-3

Omega 3 fatty acids have been proposed as a treatment for depression, often suggested to be combined with other treatments. One small pilot study of childhood depression (ages 6–12) suggested that omega 3 may have therapeutic benefits for treating childhood depression. A 2005 review of the scientific literature concluded that there were several different independent lines of evidence suggesting that omega-3 fatty acids play a role in depression, and that the theory of omega-3's role in depression was biologically plausible. The evidence includes a few double-blind randomized control trials, epidemiological studies linking low fish consumption (the primary source of omega-3) to increased rates of depression, and case-control and cohort studies of unipolar and postpartum depression indicating low blood levels of omega-3 in depressed patients.

Other essential nutrients

Folic acid and Vitamin B12 have also been proposed as a treatment for depression, especially when used in conjunction with other treatments. In particular, folic acid has been shown to improve the treatment response to other antidepressants.