UNASSIGNED: Prolonged grief disorder (PGD) is a new disorder included in the 11th edition of the International classification of diseases (ICD-11). An important remit of the new ICD-11 is the global applicability of the mental health disorder guidelines or definitions. Although previous definitions and descriptions of disordered grief have been assessed worldwide, this new definition has not yet been systematically validated.
UNASSIGNED: Here we assess the validity and applicability of core items of the ICD-11 PGD across five international samples of bereaved persons from Switzerland (N = 214), China (N = 325); Israel (N = 544), Portugal (N = 218) and Ireland (N = 830).
UNASSIGNED: The results confirm that variation in the diagnostic algorithm for PGD can greatly impact the rates of disorder within and between international samples. Different predictors of PGD severity may be related to sample differences. Finally, a threshold for diagnosis of clinically relevant PGD symptoms using a new scale, the International Prolonged Grief Disorder Scale (IPGDS), in three samples was confirmed.
UNASSIGNED: Although this study was limited by lack of questionnaire data points across all five samples, the findings for the diagnostic threshold and algorithm iterations have implications for clinical use of the new ICD-11 PGD criteria worldwide.

Prolonged grief disorder (PGD) is a new mental health disorder, recently introduced in the International Classification of Diseases (ICD-11), World Health Organization Classification of Diseases (WHO). The new ICD-11 guidelines reflect an emerging wave of interest in the global applicability of mental disorders. However, the selection of diagnostic core features in different cultural contexts has yet to be determined. Currently, there is debate in the field over the global applicability of these guidelines. Using semi-structured interviews with 14 key informants, we explored the acceptability of ICD-11 guidelines for PGD according to Japanese health professionals as key informants. The interviews revealed symptoms of grief possibly missing in the ICD-11 PGD guidelines including somatization and concepts such as hole in the heart. Additionally, sociocultural barriers such as stigma and beliefs about the social desirability of emotions may challenge patients\' and clinicians\' acceptance of the new ICD-11 criteria.

The World Health Organization (WHO) International Classification of Disease (ICD-11) is expected to include a new diagnosis for prolonged grief disorder (ICD-11PGD). This study examines the validity and clinical utility of the ICD-11PGD guideline by testing its performance in a well-characterized clinical sample and contrasting it with a very different criteria set with the same name (PGDPLOS).
We examined data from 261 treatment-seeking participants in the National Institute of Mental Health (NIMH)-sponsored multicenter clinical trial to determine the rates of diagnosis using the ICD-11PGD guideline and compared these with diagnosis using PGDPLOS criteria.
The ICD-11PGD guideline identified 95.8% [95% confidence interval (CI) 93.3-98.2%] of a treatment-responsive cohort of patients with distressing and impairing grief. PGDPLOS criteria identified only 59.0% (95% CI 53.0-65.0%) and were more likely to omit those who lost someone other than a spouse, were currently married, bereaved by violent means, or not diagnosed with co-occurring depression. Those not diagnosed by PGDPLOS criteria showed the same rate of treatment response as those who were diagnosed.
The ICD-11PGD diagnostic guideline showed good performance characteristics in this sample, while PGDPLOS criteria did not. Limitations of the research sample used to derive PGDPLOS criteria may partly explain their poor performance in a more diverse clinical sample. Clinicians and researchers need to be aware of the important difference between these two identically named diagnostic methods.