I am wondering what kind of evidence there is between omega 3s and depression?
Chronic depression is a public health concern in numerous countries as indicated by statistics from the World Health Organization (WHO). The pioneering work of Dr. Joe Hibbeln from the NIH in Bethesda, Maryland showed an inverse relationship between DHA levels in breast milk of lactating women and the risk of postpartum depression. Other studies have shown inverse relationships between fish consumption (as a source of DHA+EPA) and various aspects of depressive illness although not all studies are consistent to date. In addition, supplementation with DHA/EPA omega-3 fatty acids has been found to reduce depression in some short-term intervention trials usually of short durations and with small numbers of subjects. A recent study from Israel by Nemets et al. (Am. J. Psychiatry, 163: 1098-1102 (2006)) showed a very pronounced reduction in childhood depression (measured by the Childhood Depression Rating Scale and other parameters) in newly-diagnosed subjects not yet on medication. The children (mean age of 10 years) referred to the depression clinic were assigned to a placebo (control) supplement or active capsules providing 600 mg per day of DHA/EPA over a 16 week period. By six weeks of supplementation, the omega-3 grouped showed a marked reduction in the depression rating as compared to controls and this benefit was maintained up to the 16 week time period when the study was terminated.
No official recommendations have been forthcoming to date with respect to the use of omega-3 fatty acids as DHA/EPA in depression per say due to the paucity of long-term and large-scale studies. Nonetheless, an increasing number of individuals are self-medicating with DHA/EPA supplementation and some medical personnel (particularly psychiatrists) are introducing the subject in private consultation with individual patients on a case by case basis. Of course, any one with a medical condition should seek advice through their physician, specialist, and appropriate qualified medical personnel.