The influence of dietary fatty acids (FAs) other than omega-3 FAs on mood has been largely overlooked. The authors prospectively assessed the association between dietary linoleic and oleic FAs and the risk of severe depressed mood (SDM) among 4856 adults aged 25-74 years who were examined in 1971-1975 as a part of a national survey. Intakes of FAs were obtained at baseline from a 24-hour recall and categorized into thirds. SDM was defined as Center for Epidemiologic Studies Depression Scale scores at follow-up survey >or=22 or taking anti-depression medication. After an average of 10.6 years of follow-up, the proportion of individuals with SDM were 11.45 (SE=0.96) % and 17.45(1.05) % respectively among 1947 men and 2909 women. The odds ratios (ORs) were 1 (reference), 1.64(95% CI=1.06, 2.54) and 2.34 (1.41, 3.87) respectively for men with lowest, middle and highest third of linoleic FA intake (p for trend=0.001); the ORs were 1 (reference), 0.88 (0.56, 1.38) and 0.48 (0.25, 0.95) respectively for women with lowest, middle and highest third of oleic FA intake (p for trend=0.0347). No association was observed from saturated FA. These estimates were adjusted for fish consumption at baseline and major physical diseases at follow-up. The authors concluded that increased intake of oleic FA was associated with reduced risk among women while increased intake of linoleic FA was associated with increased risk of SDM among men.