Relationship between Heart Rate Variability and Major Depressive Disorder in Young Adults

Abstract

Objectives: Heart rate variability (HRV) is a cost-effective and convenient tool to assess autonomic dysfunction, which has been sparsely studied in patients with major depressive disorder (MDD) in India. Primary objective is to study the relationship between HRV measures and MDD in young adults with standard normal values. Secondary objective is to evaluate the changes in HRV measure with symptom severity. Methods: A total of 80 drug-naïve MDD patients, aged 18-45 years, without any major psychiatric or cardiovascular comorbidities, were enrolled in the study. Severity was determined using the Hamilton Depression Rating Scale. Time and frequency domain variables of HRV were analysed from electrocardiogram recordings. The time and frequency domain variables were compared with that of standard normal values using unpaired Student's t-test. These variables were also compared between mild, moderate, and severe MDD using analysis of variance (ANOVA). A p-value <0.05 was considered statistically significant. Results: Highly significant differences between patients and standard values were observed in mean interbeat interval (RR) of time domain variable (p <0.0001) and in low frequency (LF) power (p <0.0001), high frequency (HF) power (p <0.0001) and LF/HF ratio (p <0.0001) of frequency domain variables. Significant associations of HRV measures were also found in mean RR interval (F = 19.96, p <0.000), LF (F=7.53, p <0.001), HF (F = 4.62, p <0.0126), and LF/HF ratio (F = 140.21, p<0.000) among different symptom severity groups. Conclusion: This study provides evidence to implicate HRV as a cost-effective and convenient tool to assess autonomic dysfunction in MDD in young adults.