Persistence of depressive symptoms and cardiovascular death among patients with affective disorder.

OBJECTIVE: Studies of both community and clinical samples have associated depressive symptoms with risks for subsequent cardiovascular morbidity and mortality. Because the physiological mechanisms thought to underlie this link would be cumulative in their effects, the following analyses tested the prediction that risks for cardiovascular death would increase in proportion to the persistence of depressive symptoms in a long-term follow-up.
METHODS: Baseline assessment was performed as patients sought treatment for major depressive disorder, mania, or schizo-affective disorder. Follow-up evaluations occurred semiannually for the next 5 years and annually thereafter. The 903 patients described, observed for a mean of 11.0 years (SD = 5.2 years), were divided into thirds according to the proportion of follow-up weeks in episodes of major depressive disorder, schizoaffective disorder, or intermittent depressive disorder. The resulting groups were then compared by cumulative risks of cardiovascular death.
RESULTS: Patients whose depressive symptoms were the most persistent were no more likely to die of cardiovascular causes than were those with the fewest weeks ill. A regression analysis showed that older age and the presence of cardiovascular disease at baseline, but not the subsequent chronicity of depressive symptoms, predicted cardiovascular death.
CONCLUSIONS: The physiological concomitants of depressive illness apparently do not promote cardiovascular mortality in a cumulative manner. Efforts should be directed toward identification of risk factors common to both lifetime depressive symptoms and cardiovascular morbidity.