OBJECTIVE: Although it is possible that the association between depression and the metabolic syndrome is a "two-way street," the metabolic syndrome as a predictor of depression has been little investigated. We examined whether the metabolic syndrome is associated with the onset of depressive symptoms in a cohort of middle-aged British civil servants. RESEARCH DESIGN AND METHODS: Analyses included 5,232 participants (41-61 years of age) from the Whitehall II prospective cohort study. Depressive symptoms were assessed in 1991-1993 and again 6 years later using the depression subscale from the 30-item General Health Questionnaire. Metabolic syndrome was assessed in 1991-1993, according to National Cholesterol Education Program criteria. RESULTS: Presence of the metabolic syndrome was associated with an increased risk of future depressive symptoms, odds ratio 1.38 (95% CI 1.02-1.96) after adjustment for potential confounders. Of the five components, only central obesity, high triglyceride levels, and low HDL cholesterol levels predicted depressive symptoms. These components explained most of the association between the metabolic syndrome and the onset of depressive symptoms. CONCLUSIONS: Our results suggest that the metabolic syndrome, in particular the obesity and dyslipidemia components, is predictive of depressive symptoms.