Association between depressive symptoms and changes in sleep condition in the grieving process.

Purpose: Bereaved families often suffer from insomnia and depression. However, the associations between depressive state and changes in sleep condition during the grieving process have not been investigated. This study aimed to clarify the prevalence of insomnia symptoms and to explore associations between present depressive state and changes in sleep condition in the grieving process in bereaved families of Japanese patients with cancer.
Methods: A cross-sectional, multicenter survey was conducted in 103 certified palliative care units. A questionnaire asking insomnia symptoms and depressive symptoms by the Center for Epidemiological Studies Depression Scale (CES-D) was mailed to bereaved families (N = 987). The association between present depressive state (CES-D ≥7) and sleep conditions in the grieving process were analyzed.
Results: A total of 561 families were enrolled for analysis. Fifty-three percent of family members were considered to be in a depressive state at the time of the investigation. Prevalence of past insomnia was 86.5% at "within a few weeks before the patient's death" (T1) and 84.5% at "within 6 months after the patient's death" (T2) in all bereaved family members. However, in contrast to decreased severity of insomnia between T1 and T2 in the non-depressive group (p < 0.05), severity of insomnia was unchanged in the depressive group during this period (p = 0.139).
Conclusions: Insomnia symptoms are highly prevalent and may be associated with posthumous depressive state in bereaved Japanese families. These results suggest the need for careful observation of changes in sleep condition during the grieving process.