Relationship between major depression and heart rate variability.: Clinical consequences and implications for antidepressive treatment

A high sympathetic and/or a low cardiovagal activity in patients with major depression (MD) may contribute to the higher cardiac morbidity and mortality of MD patients. Standardized tests of heart rate variability (HRV) allow a quantitative estimation of autonomic nervous system function. However, previous studies on the relationship between HRV and MD have revealed conflicting results. Our study compared time and frequency domain HRV indices (5-min resting study, deep breathing test, Valsalva test) between 32 patients with MD (DSM-III-R) and 64 non-depressed controls. The severity of depressive symptoms was assessed by the Hamilton Depression Scale (HAM-D); patients were divided into subgroups with moderate (M-HAM-D