Depressive symptoms are associated with increased systemic vascular resistance to stress

Objective: The deleterious effects of major depressive disorder on cardiovascular (CV) functioning are well known. However, the etiologic mechanisms underlying this association are incompletely understood. In the current study, subjects with varying degrees of depressive symptoms performed a stress task while CV reactivity was measured. We hypothesized that high levels of depressive symptoms would be associated with altered CV reactivity. Methods: Ninety-one healthy volunteer subjects performed reactivity testing while measures of impedance cardiography and autonomic nervous system function were obtained. Subjects completed the Center for Epidemiological Studies Depression Scale (CES-D) and were categorized into either the high depressive (i.e., CES-D >= 16) or low depressive (i.e., CES-D < 16) symptoms group. Results: Task performance was associated with increases in systemic vascular resistance (SVR) (p =.001), mean arterial pressure (p = .001), and heart rate (p = .005), and decreases in cardiac output (p =.001), heather index (p =.001), and stroke volume (p = .05). After controlling for screening mean arterial pressure, an interaction effect of stress by mood group on SVR (p = .01) was observed; subjects with high amounts of depressive symptoms manifested significantly greater SVR at baseline and in response to a stressor task than did subjects with low amounts of depressive symptoms. Conclusions: These results suggest a mechanism that may partially explain the increased CV morbidity associated with depressive symptoms. In future studies, it may be useful to examine if treatment of depressive symptoms alters CV reactivity.