A comprehensive investigation of comorbidities of prolonged grief disorder in a bereaved inpatient psychiatric sample.

Prolonged Grief Disorder (PGD) was recently added to ICD-11 and DSM-5-TR. Depression and Posttraumatic Stress Disorder (PTSD) are frequent comorbidities, but findings regarding comorbid somatoform disorder and personality disorders remain mixed and studies with severely impaired patients are scarce. It was therefore the objective of the present study to examine comorbidities of PGD in a bereaved inpatient psychiatric sample. We assessed N = 101 bereaved inpatients in a psychiatric hospital with clinical interviews and self-report questionnaires. We calculated differences between patients with and without a PGD-diagnosis in number and type of comorbid disorders as well as associations between the severity of PGD and comorbid disorders. On average, patients had 2.53 comorbid psychiatric diagnoses. Patients with and without a PGD-diagnosis did not differ in their number of comorbid diagnoses, and there was no association between number of comorbid diagnoses and PGD-severity. However, patients with PGD, had significantly more comorbid diagnoses belonging to neurotic-, stress-related and somatoform disorders of the ICD-10. Patients with PGD also had significantly higher scores in self-reported depressive, PTSD-, and somatoform symptoms, as well as the negative affectivity personality domain than those without a PGD diagnosis. To the best of our knowledge, this is the first study to provide insights into comorbidities of PGD in a bereaved inpatient psychiatric sample. It highlights the importance of considering PGD symptoms as part of the complaints of bereaved patients to achieve a tailored treatment approach. Future longitudinal studies are needed to unveil relationships between pre-existing mental disorders and PGD.