Surrogate caregivers for bereaved patients in the intensive care unit (ICU) may suffer from prolonged grief disorder (PGD), posttraumatic stress disorder (PTSD), and depression. Given the duration criterion for PGD, there is a dearth of relevant studies and a wide variety of assessment time frames that are either insufficient or inappropriate. With an evaluation time frame reflecting the PGD duration criterion, researchers sought to identify the temporal reciprocal associations between PGD, PTSD, and depressive symptoms among family surrogates of ICU decedents’ throughout the first 2 years following death. At 6, 13, 18, and 24 months after the loss, 303 family surrogates of ICU decedents from 2 research hospitals were assessed for PGD, PTSD, and depressive symptoms using 11 items from the Prolonged Grief Disorder-13, the Impact of Event Scale—Revised, and the depression subscale of the Hospital Anxiety and Depression Scale.

They used cross-lagged panel modeling, where autoregressive coefficients show that variables are consistent across time, and cross-lagged coefficients show how strong the inverse correlations are between variables over time. Depressive, post-traumatic stress disorder, and borderline personality disorder symptoms did not change over time (autoregressive coefficients ranged from 0.570 to 0.673, 0.375 to 0.687, and 0.591 to 0.655, respectively). Predicting PGD (0.146) and PTSD (0.208) symptoms 13 months after the loss was shown by depressed symptoms measured 6 months after the loss. PGD symptoms did not predict depressive symptoms. Posttraumatic stress disorder symptoms were a predictor of major depressive disorder in the year following a death in the family (0.175–0.278). Symptoms of PGD were a reliable predictor of future PTSD symptoms in the first 2 years after death (0.180-0.263), while PTSD symptoms were a reliable predictor of future PGD symptoms only in the second year after death (0.190–0.214). In the second year following a loss, there is a reciprocal relationship between PGD and PTSD symptoms.

The effects of PTSD, major depression, and PGD might last up to 2 years after a loss. Long-lasting PTSD symptoms were associated with extended depression and PGD symptoms beyond the first bereavement year, and higher PGD symptoms at 6 months post-loss contributed to the worsening of PTSD symptoms over time. Bereaved surrogates are better able to grieve well and prevent PGD, PTSD, and depression from developing if their symptoms are identified and treated as early as 6 months after the bereavement.