Long-chain n-3 fatty acid levels in baseline serum phospholipids do not predict later occurrence of depressive episodes: a nested case-control study within a cohort of middle-aged French men and women.

The goal of this study was to seek the relations between baseline n-3 PUFA status and the later occurrence of depressive episodes in a French cohort of middle-aged men and women, the SU.VI.MAX study. A nested case-control study was designed within the cohort: cases with at least two depressive episodes during the 8-year follow-up were paired to non-depressed controls, antidepressant prescriptions being taken as markers of depressive episodes. The fatty acid profiles of baseline serum phospholipids have been determined. Results were analyzed using logistic regression and principal component analysis, taking into account depression history and demographic and lifestyle confounders. There was no consistent association of depression risk with any serum fatty acid, and in particular there was no association of depression risk with the long-chain n-3 PUFA eicosapentaenoic, docosapentaenoic and docosahexaenoic acids. This study does not support the hypothesis of a predictive value of n-3 PUFA status for depression in population settings.