A propensity score-adjusted HRV analysis of social avoidance and distress in patients with panic disorders

Panic disorder (PD) may accompany elevated social avoidance and distress (SAD). Higher SAD in patients with PD predicts a poorer prognosis and response to treatment. As heart rate variability (HRV) reflects the self-regulatory capacity underlying SAD, applying HRV to distinguish PD heterogeneity would be clinically beneficial in formulating personalized treatment strategies. We hypothesized that HRV would be lower in patients with PD and severe SAD (PD-SAD group) than in those without SAD (PD group). A total of 288 patients met the eligibility criteria, with complete collection of variables of interest and HRV. The inverse probability of treatment weighting (IPTW) method was used to balance the groups for the baseline characteristics of patients. Following IPTW adjustment, the average treatment effects were computed using inverse propensity weighting with regression adjustment (IPW-RA). All characteristics were similar in both groups after IPTW adjustment. The PD-SAD group showed a decreased tendency in time domain parameters, including mean heart rate, SDNN, RMSSD, and pNN50 with a nonlinear domain of SD1. However, no significant intergroup differences were observed in the frequency domain. Higher SAD in PD was associated with reduced HRV, mainly in the time domain, which may be attributed to the shared neural networks between dysfunctional self-regulation statuses, as indexed by reduced HRV. As respiratory sinus arrhythmia is mainly reflected in the frequency domain, the time domain may be more reliable for identifying heterogeneity within patients with PD, who are frequently associated with respiratory pattern abnormalities.