Autonomic and respiratory changes in young and old adults with non-clinical depression and anxiety

Abstract

Previous research has found that good health is tied to flexibility in multiple bodily systems, with reduced variability signalling poor health. Depression and anxiety are found to correlate with lower heart rate variability (HRV), suggesting reduced respiratory rate variability (RRV) due to linked heartbeat-respiration dynamics. However, few studies have explored HRV in non-clinical samples of young and old adults with reported depression and anxiety symptoms, and none have examined their relationship with RRV. We predict that across both young and old subjects, there will be decreased HRV and RRV indices in individuals with higher depression and anxiety scores. Participants were administered the GAD-7 and PHQ-9, while respiratory sinus arrhythmia (RSA), respiration rate, and indices of HRV and RRV were extracted from collected ECG data. Significant relationships were found in young subjects, with depression scores negatively associated with HF-HRV, in line with results found in clinical populations. Novel findings suggest lowered RRV in young subjects with higher levels of anxiety, indicating reduced flexibility and short-term ANS dysregulation, which is consistent with previous studies examining other indices of respiratory variability and anxiety. Our results suggest that in young subjects with affective symptoms, a decrease in parasympathetic activity is a typical physiological response. However, given effects reduced parasympathetic activity has on resultant physiological responses, findings could suggest that reductions in HRV could be a risk marker for depression.