Characteristics in Heart Rate Variability associated with Early Life Stress in Patients with Major Depressive Disorder

주요우울장애 환자에서 생애초기스트레스와 연관된 심박변이도의 특성

Objectives : Early life stress (ELS) may have impact on functions of the autonomic nervous system. Heart rate variability (HRV) is a reliable psychophysiological marker for functions of the autonomic nervous system. The purpose of this study was to investigate characteristics of HRV associated with ELS in patients with major depressive disorder (MDD). Methods : We compared HRV measures of MDD patients with ELS and without ELS in a 5-minute resting-state electrocardiogram recoding. Forty subjects participated in the study (25 with ELS, 15 without ELS). The Mann-Whitney test was conducted to identify group differences. Results : We found significant group differences in standard deviation of the NN interval (SDNN) and total power (TP). SDNN was lower in the ELS group (M=38.80 ms, SD=13.05 ms) than in the Non-ELS group (M=53.53 ms, SD=19.47 ms). TP was lower in the ELS group ($M=7.07ms^2$, $SD=0.69ms^2$) than in the Non-ELS group ($M=7.72ms^2$, $SD=0.77ms^2$). Conclusion : ELS may have a negative impact on the autonomic nervous system function in patients with MDD. ELS and dysfunction of autonomic nervous system should be considered in treatment for patients with MDD.