Experiential avoidance moderates the association between motivational sensitivity and prolonged grief but not posttraumatic stress symptoms.

Within the current theoretical frameworks used in grief and bereavement research, it remains unclear which individual factors confer risk for specific bereavement-related mental health problems, such as posttraumatic stress disorder (PTSD) and prolonged grief disorder. The present study investigated individual differences in motivational sensitivity and self-regulatory processes in a sample of 326 bereaved individuals who experienced sudden and/or unexpected death losses. We (1) examined associations between behavioral activation system (i.e., orientation to rewarding stimuli) and behavioral inhibition system (i.e., orientation to aversive stimuli) sensitivity and bereavement-related mental health problems (i.e., PTSD and prolonged grief symptoms), and (2) explored whether experiential avoidance (i.e., effortful avoidance of internal stimuli) would moderate such associations. Results revealed PTSD was more strongly associated with behavioral inhibition system sensitivity, while prolonged grief symptoms more strongly associated with behavioral activation system sensitivity. In particular, drive sensitivity - a dimension of the behavioral activation system - appeared uniquely associated with prolonged grief symptoms, especially in those who endorsed high experiential avoidance. Findings support a theoretical reconceptualization of prolonged grief as a reward system disorder. This reconceptualization may aid in further understanding mechanisms of bereavement-related mental health problems and related risk factors.