An acute major depressive episode in unmedicated men was associated with significantly lower complexity of heart rate dynamics during sleep compared to healthy controls (adjusted difference 1.8, p=0.02).
Case-Control (n=45)
No
Does an acute major depressive episode reduce the neuroautonomic complexity of heart rate dynamics during sleep in unmedicated men compared to healthy controls?
Acute major depressive episodes are associated with a significant decrease in the neuroautonomic complexity of heart rate dynamics during sleep, suggesting degraded autonomic adaptability.
Mean Difference: 1.8 (95% CI 0.3–3.3)
Absolute Event Rate: 15.4% vs 17.6%
p-value: p=0.02
Major depression affects multiple physiologic systems. Therefore, analysis of signals that reflect integrated function may be useful in probing dynamical changes in this syndrome. Increasing evidence supports the conceptual framework that complex variability is a marker of healthy, adaptive control mechanisms and that dynamical complexity decreases with aging and disease. We tested the hypothesis that heart rate (HR) dynamics in non-medicated, young to middle-aged males during an acute major depressive episode would exhibit lower complexity compared with healthy counterparts. We analyzed HR time series, a neuroautonomically regulated signal, during sleep, using the multiscale entropy method. Our results show that the complexity of the HR dynamics is significantly lower for depressed than for non-depressed subjects for the entire night (P<0.02) and combined sleep stages 1 and 2 (P<0.02). These findings raise the possibility of using the complexity of physiologic signals as the basis of novel dynamical biomarkers of depression.
Leistedt et al. (Tue,) conducted a case-control in Major depressive episode (n=45). Acute major depressive episode vs. Healthy controls was evaluated on Short-term complexity index (scales 1-8) of heart rate dynamics during sleep (MD 1.8, 95% CI 0.3-3.3, p=0.02). An acute major depressive episode in unmedicated men was associated with significantly lower complexity of heart rate dynamics during sleep compared to healthy controls (adjusted difference 1.8, p=0.02).