Sixteen women with postpartum depression were randomly assigned to receive 0.5 g/day, 1.4 g/day, or 2.8 g/day of omega-3 fatty acids from fish oil for eight weeks. In the group as a whole, the mean score on the Hamilton Rating Scale for Depression decreased (improved) by 48.8% (from 19.1 to 10.0). None of the different fish oil doses was significantly more effective than the other doses. The lowest dose used in this study was equivalent to 4.7 g/day of fish oil.
Previous studies have suggested that consuming adequate amounts of long-chain omega-3 fatty acids (i.e., eicosapentaenoic acid and docosahexaenoic acid from fish oil) during pregnancy may reduce the incidence of preterm delivery and enhance the development of the brain and visual system of the fetus. The results of the present study suggest that fish oil may also be useful for treating (and presumably preventing) postpartum depression. It is important for pregnant and nursing women to use fish oil products that are low in mercury, so as not to expose the fetus and infant to excessive amounts of this toxic metal.
Supplementing with alpha-linolenic acid from flaxseed oil or other vegetable oils may not be as effective as using fish oil, because the capacity of the body to convert alpha-linolenic acid to eicosapentaenoic acid and docosahexaenoic acid is limited.
Other treatments that have been successful, in my experience, for treating postpartum depression include 1) intramuscular injections of vitamin B12 (1,000 mcg) and folic acid (2.5 mg) once or twice a week for several weeks and 2) low doses of thyroid hormone when the clinical or laboratory picture is suggestive of hypothyroidism.
Freeman MP, et al. Randomized dose-ranging pilot trial of omega-3 fatty acids for postpartum depression. Acta Psychialr Scand. 2006;113:31-35.
Reprinted with exclusive permission from The Townsend Letter, Oct. 2007.