Autonomic evidence that avoidance matters in the mourning process: A prospective observational study in Japan

Evidence provides support for the therapeutic benefits of targeting avoidance in prolonged grief. However, it is not clear whether avoidance interferes with mourning through altered resilience to stress, as measured by heart rate variability (HRV).

Thirty-five adults (30 female; mean age: 39.2 years), who had been bereaved for more than one year, participated in this prospective, observational study. At each of the initial assessments and up to six-month follow-ups, grief symptoms were assessed using the Complicated Grief Questionnaire, and a resting electrocardiogram was recorded to extract the high-frequency component of HRV (HF-HRV). To differentiate avoidance from grief itself, principal component analysis was used.

A nonlinear cross-sectional relationship was observed between avoidance and HF-HRV (coefficient = 0.29, p = .003); the lower the avoidance, the lower the HF-HRV in the low avoidance group. Grief improved only in the low avoidance group longitudinally. The observed relationship between increased HF-HRV and decreased grief was modified by the avoidance group, such that the low-avoidance group drove this association (estimate -0.53, 95% CI -0.86, -0.21, p = .001), while the high-avoidance group did not (estimate 0.44, 95% CI -0.32, 1.20, p = .26).

Despite its palliative gain, avoidance relates to the maintenance of grief longitudinally through attenuated autonomic resilience to stress.