Same Name, Same Content? Evaluation of DSM-5-TR and ICD-11 Prolonged Grief Criteria

What is the public health significance of this article? This study identified differences in diagnostic rates between prolonged grief disorder (PGD) diagnosed according to DSM-5-TR and to ICD-11. The differences were mainly attributable to the time criterion and to the presentation of potential core symptoms (e.g., attachment disturbance symptoms). Both diagnoses are based on a unidimensional grief construct, which may challenge the distinction between the main and the additional symptoms. Given the possible increase in PGD prevalence rates due to the coronavirus disease (COVID-19) pandemic, our findings should remind practitioners to pay attention on which diagnostic rule the PGD diagnosis is based before initiating further treatment and to consider a stepped-care approach if there is doubt as to whether full-blown PGD is present. Objective: Investigating the concordance of prolonged grief disorder (PGD) criteria that have been recently introduced to the 5th text revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5-TR) and the International Classification of Diseases 11(th) Revision (ICD-11). Method: N = 193 treatment-seeking bereaved adults were assessed with the prolonged grief disorder 13 + 9 interview. Data were examined in terms of (a) diagnostic rates for PGD(DSM-5-TR) and PGD(ICD-11), including increases of the PGD(ICD-11) accessory symptom threshold (PGD(ICD-11-X+)) and time criterion (PGD(ICD-11-12 months)), (b) dimensionality, (c) the frequency with which single PGD symptoms occur, and (d) concurrent validity in terms of psychological symptoms and loss-related characteristics. Results: The diagnostic rate of PGD(DSM-5-TR) (52%) was significantly lower than that of PGD(ICD-11) (76%) and agreement between the two criteria sets was moderate, kappa = 0.51, 95% CI [0.47-0.55]. Increasing the PGD(ICD-11) accessory symptom threshold did not improve the diagnostic agreement. In contrast, increasing the ICD-11 time criterion led to almost perfect agreement between PGD(ICD-11-12 months) and PGD(DSM-5-TR), kappa = 0.91, 95% CI [0.89-0.93]. Confirmatory factor analysis results indicated a one-factor model fit best for both PGD(DSM-5-TR) and PGD(ICD-11.) Emotional pain symptoms (e.g., guilt) were predominantly reported by patients with a PGD(ICD-11) diagnosis, while attachment disturbance symptoms (e.g., identity disruption) were reported more often by patients with a PGD(DSM-5-TR) diagnosis. Conclusions: Despite methodological limitations of this study, results indicate discordance in PGD(DSM-5-TR) and PGD(ICD-11) regarding diagnostic rates and single symptom occurrence, while the factor structure is similar. Changes in the ICD-11 time criterion could reduce these differences.