Fish consumption and severely depressed mood, findings from the first national nutrition follow-up study.

The evidence obtained from prospective studies to support the hypothesis that fish consumption may improve mental status remains limited. The current study prospectively assessed a low frequency of fish consumption as a risk factor for depressed mood. Included were 5068 adults aged 25-74 years examined in 1971-1975 as the baseline of the First National Health and Nutrition Examination Survey Follow-up Study. Frequency of eating fish at baseline was obtained using a 3-month food frequency questionnaire. Severely depressed mood (SDM) was defined as the Center for Epidemiologic Studies Depression Scale scores ≥22 or taking anti-depressants. After an average of 10.6 years of follow-up, among men (n=2039), the percentage of individuals with SDM was 11.7%. Compared with frequent consumers (more than once a week), the odds ratios (ORs) were 1.43 (95%CI=0.66-3.11) and 2.08 (1.08-4.09) respectively for the men eating fish once a week and less than once a week (p for trend=0.03). Among women (n=3029), the percentage of individuals with SDM was 17.89%. The ORs were 1 (reference), 0.91 (0.68-1.22) and 1.15 (0.83-1.59) respectively for the women eating fish more than once, once, and less than once a week. These estimates were obtained after adjustment for indicators of social deprivation and major physical diseases. The study concluded that independently from social deprivation and physical diseases, low fish consumption was a risk factor for SDM among men. Further studies are needed to confirm these findings and elucidate mechanisms for the difference between men and women.