中島 聡美

INTRODUCTION: 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). METHODS: 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. RESULTS: 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). CONCLUSION: Despite its palliative gain, avoidance relates to the maintenance of grief longitudinally through attenuated autonomic resilience to stress.

AIM: This study aimed to examine the impact of grief and depression on reduced productivity in and outside work among bereaved family members of individuals with cancer. METHODS: We used the data from the J-HOPE-4 study, a nationwide cross-sectional survey involving the bereaved families of individuals with cancer in inpatient hospices and palliative care units across Japan. We evaluated the participants' level of grief on the Brief Grief Questionnaire, their level of depression on the Patient Health Questionnaire, and their level of productivity loss on the Work Productivity and Activity Impairment Questionnaire. RESULTS: Of the participating 902 bereaved families, 98 individuals (10.9%) corresponded to probable prolonged grief disorder (PGD) and 367 (40.7%) to possible PGD. Of the 217 individuals (24.1%) corresponded to mild depression, 89 (9.9%) to moderate depression, and 44 (4.9%) to moderate-to-severe depression. The work-related productivity losses in possible and probable PGD samples were 12.6% and 15.7%, respectively. The work-related productivity losses due to mild, moderate, and moderate-to-severe depression were 8.8%, 19.4%, and 32.5%, respectively. The productivity losses outside work in individuals with possible and probable PGD were 21.6% and 30.9%, respectively. The productivity losses in mild, moderate, and moderate-to-severe depression were 22.6%, 32.8%, and 37.0%, respectively. CONCLUSION: The impact of grief on productivity loss was comparable with that of mild to moderate depression. Both the severity of grief and depression were significantly associated with productivity losses outside work, while only depression was significantly associated with work-related productivity loss.

Abstract Introduction Light information critically influences sleep and emotion regulation. Nighttime light exposure has been suggested to disrupt sleep and predict poor health outcomes. However, little is known about how sleep changes after bereavement and how sleep changes contribute to prolonged grief. We examined the association between nighttime light exposure and sleep continuity in bereaved adults. Methods In this cross-sectional study, 30 adults who had been bereaved for at least one year, wore a wrist actigraphy for seven consecutive nights. Bedroom light intensity from bedtime to rising time (BLI, lux) and sleep continuity variables were estimated from the wrist actigraphy. We tested the association between BLI and natural log-transformed sleep continuity measures and explored factors that modify this relationship in multivariable-adjusted generalized linear models. Results Nearly 40% of participants were diagnosed with current prolonged grief disorder (PGD), even after a median of 2.5 years since the loss. The mean BLI was 3.72 lux. Overall, higher BLI was associated with lower sleep continuity, independently of psychological, physical, and sleep covariates, including total sleep time, sleep midpoint, and season. This was particularly evident for sleep fragmentation index (B = 0.076; 95% CI, 0.029–0.122; exp[B] = 1.079), indicating that every 1-unit increase in BLI was associated with a 7.9% increase in sleep fragmentation index. Moreover, the association between BLI and sleep fragmentation was more robust in participants with current PGD, those who had lost a child or spouse, and those whose loss was violent or sudden than in those without each of these characteristics. Similarly, depressive symptoms, hypnotic use, and regular alcohol drinking also modified the relationship between BLI and sleep fragmentation. Conclusion These data strengthen the evidence for nighttime light exposure and sleep fragmentation. Our findings suggest that post-loss stress and vulnerability factors interact to disrupt sleep through increased light sensitivity at night. Further research is needed to determine the role of sleep fragmentation in the maintenance of and recovery from grief. Support (if any) This work was supported by the Intramural Research Grant for Neurological and Psychiatric Disorders of NCNP (Grant numbers #3-1 and #6-1) and KAKENHI (Grant numbers #20H01774 and #23H01045).