Troubled Hearts: Association Between Heart Rate Variability and Depressive Symptoms in Healthy Children.

Heart rate variability (HRV) captures the change in timing of consecutive heart beats and is reduced in individuals with depression and anxiety. The present study investigated whether typically-developing children without clinically recognized signs of depression or anxiety showed a relationship between HRV and depressive or anxiety symptoms. Children aged 9-14 years (N = 104) provided three minutes of cardiac signal during eyes closed rest and eyes open rest. The association between high frequency HRV, low frequency HRV, root mean square of the successive differences (RMSSD), and pNN20 versus depressive symptoms (NIH Toolbox and Child Behavior Checklist) was investigated. Results partially confirm our hypothesis, with pNN20 positively correlated with the self-reported depression measure of loneliness while controlling for age, sex, social status, and physical activity. The association was stronger in male participants. However, there is no consensus in the literature about which HRV measures are associated with depressive symptoms in healthy children. Additional studies are needed which reliably account for variables that influence HRV to establish whether certain HRV measures can be used as an early marker for depression risk in children.