Interactions Between Depression, Autonomic Dysfunction, Inhibitory Control and Reaction Time: Insights From Heart Rate Variability During Continuous Performance Test

Objective This study investigates the relationship between depression, autonomic dysfunction, inhibitory control (IC), and reaction time by analyzing heart rate variability (HRV) during a cognitive task. Methods A total of 29 healthy males and 25 males diagnosed with depression (aged 20–35 years) participated. HRV data were recorded during the Conners Continuous Performance Test-II (CCPT-II) in each group. HRV parameters, including mean RR intervals, standard deviation of normal-to-normal heartbeats (SDNN), low-frequency power with logarithm (lnLF), and high-frequency power with logarithm (lnHF), were analyzed and correlated with IC (d’) and reaction time. Results The depression group exhibited significantly lower lnHF values compared to the healthy group. SDNN and lnLF decreased in both groups during CCPT-II. In the healthy group, d’ correlated significantly with SDNN, lnLF, and lnHF at t14 and across the test duration. However, in the depression group, only RR intervals correlated with d’. A significant correlation between reaction time and HRV was noted at t14 in the healthy group, suggesting autonomic nervous system (ANS) involvement in cognitive performance. Conclusion Reaction time in healthy individuals correlated with ANS function during later stages of CCPT-II, whereas depression disrupted this association. The lower d’ in the depression group was not due to a speed-accuracy trade-off but rather a more pronounced neural network impairment. These findings suggest that depression impairs both IC and autonomic regulation.