The Impact of Complicated Grief on Diurnal Cortisol Levels Two Years After Loss: A Population-Based Study

Objective Few studies have focused on the effect of complicated grief—unresolved and prolonged grief—on the neuroendocrine systems. The present study examined the association of complicated grief and normal grief with the diurnal cortisol patterns in a large population-based study. Methods This study was set in the Rotterdam Study and comprised 2084 persons aged older than 55 years (mean [SD] age, 64.9 [5.5] years). Participants were assessed with the Complicated Grief Inventory and classified into no grief (n = 1922), normal grief (n = 131), or complicated grief (n = 31) if they experienced the loss in the past 2 years. Saliva samples were collected to measure cortisol levels. Morning cortisol and summary measures (area under the curve and the slope) were studied to account for the diurnal pattern of cortisol. Persons with depressive disorders were excluded, and analyses were additionally adjusted for depressive symptoms. Results Compared to normal grievers, participants with complicated grief showed lower levels of morning cortisol (11.26 vs 15.51 nmol/L; difference, −4.24; 95% confidence interval [CI] = −7.87 to −0.62; p = .022), and lower levels of overall diurnal cortisol (6.89 vs 8.98 nmol/L; difference, −2.09; 95% CI = −3.81 to −0.37; p = .017). No difference was observed in slope between both groups. Participants with complicated grief also showed lower levels of morning cortisol than the nongrievers (11.26 vs 14.71; difference, −3.46; 95% CI = −6.78 to −0.13; p = .042). In contrast, cortisol secretion patterns did not differ between persons with normal grief and nongrieving controls. Conclusions Participants with complicated grief showed low levels of morning cortisol and low overall diurnal cortisol levels characteristic for a chronic stress reaction.