Inclusion of the other in the self as a potential risk factor for prolonged grief disorder: A comparison of patients with matched bereaved healthy controls

Pathological grief has received increasing attention in recent years, as about 10% of the bereaved suffer from one kind of it. Pathological grief in the form of prolonged grief disorder (PGD) is a relatively new diagnostic category which will be included into the upcoming ICD-11. To date, various risk and protective factors, as well as treatment options for pathological grief, have been proposed. Nevertheless, empirical evidence in that area is still scarce. Our aim was to identify the association of interpersonal closeness with the deceased and bereavement outcome. Interpersonal closeness with the deceased in 54 participants (27 patients suffering from PGD and 27 bereaved healthy controls) was assessed as the overlap of pictured identities via the inclusion of the other in the self scale (IOS scale). In addition to that, data on PGD symptomatology, general mental distress and depression were collected. Patients suffering from PGD reported higher inclusion of the deceased in the self. By contrast, they reported feeling less close towards another living close person. Results of the IOS scale were associated with PGD severity, general mental distress and depression. Inclusion of the deceased in the self is a significant statistical predictor for PGD caseness.