Effect of maternal docosahexaenoic acid supplementation on postpartum depression and information processing

OBJECTIVE: The purpose of this study was to determine the effect of docosahexaenoic acid supplementation on plasma phospholipid docosahexaenoic acid content and indices of depression and information processing for women who breast-feed. STUDY DESIGN: Mothers who planned to breast-feed their infants were assigned randomly in a double-masked fashion to receive either docosahexaenoic acid (approximate to 200 mg/d) or placebo for the first 4 months after the delivery. Major outcome variables included plasma phospholipid fatty acid patterns and scores on a self-rating questionnaire of current depression symptoms. A structured clinical interview of depression, scores on another self-rating questionnaire of depression symptoms, and a laboratory measure of information processing were obtained in subgroups of the total population. RESULTS: Plasma phospholipid contents of docosahexaenoic acid at baseline were 3.15 +/- 0.78 and 3.31 +/- 0.70 (mg/dL of total fatty acids) in the docosahexaenoic acid and placebo groups, respectively. After 4 months, the plasma phospholipid docosahexaenoic acid content of the docosahexaenoic acid group was 8% higher (3.40 +/- 0.97 mg/dL), whereas that of the placebo group was 31% lower (2.27 +/- 0.87 mg/dL). Despite the higher plasma phospholipid docosahexaenoic acid content of the supplemented group after 4 months, there was no difference between groups in either self-rating or diagnostic measures of depression; information processing scores of the two groups also did not differ. CONCLUSION: Docosahexaenoic acid supplementation (approximate to 200 mg/d) for 4 months after the delivery prevented the usual decline in plasma phospholipid docosahexaenoic acid content of women who breastfeed but did not influence self-ratings of depression, diagnostic measures of depression, or information processing.