Fish consumption and depression: the Northern Finland 1966 birth cohort study

Background: Since low fish consumption and omega-3 fatty acids have recently been linked with depression, we investigated by means of a large, general population database, whether a low fish consumption is associated with increased risk of developing depression. Methods: The Northern Finland 1966 Birth Cohort was followed up prospectively from pregnancy up to the age of 31 years. The data on HSCL-25 depression subscale, doctor-diagnosed life-time depression and fish consumption (during the previous 6 months) of cohort members were obtained by postal questionnaires at the age of 31. The final number of cohort members, whose completed variable information was available in multivariate logistic analyses, was 2721 males and 2968 females. Results: After adjusting for body mass index, serum total cholesterol level and socioeconomic situation, logistic regression analyses showed that among females the risk of developing depression increased up to 2.6-fold (95%CI 1.4–5.1) among rare fish eaters when compared with regular eaters. In males, there were no significant differences between rare and regular fish eaters for any of the estimates of depression. Limitations: The data on life-time fish consumption of cohort members were not available. Conclusions: A low frequency of fish consumption was statistically significantly associated with depression in women, but not in men. Possible background-theories behind the gender difference are discussed.