Item Response Theory to Evaluate Prolonged Grief Disorder in the DSM-5-TR Among Young Adults.

Prolonged grief disorder (PGD) has been included in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition, Text Revision (DSM-5-TR). However, the factor structure of PGD has been contested and few studies have tested competing models or assessed the item-level fit of PGD symptoms included in the DSM-5-TR using Item Response Theory (IRT). Therefore, this study addressed these gaps using IRT. The results indicated that a modified three-factor model of the PGD criteria demonstrated the best model fit. IRT analyses identified items in the PGD criteria provided little information or peak information at low-to-average levels of PGD. These findings underscore the importance of assessing item-level information to improve the DSM-5-TR PGD criteria and the need to replicate study results using IRT in a representative sample. These findings and future studies are vital to improve our measurement of PGD and advance the field for future iterations of the DSM.