Content overlap analyses of ICD-11 and DSM-5 prolonged grief disorder and prior criteria-sets

The International Classification of Diseases eleventh edition (ICD-11) has recently included prolonged grief disorder (PGD), a diagnosis characterized by severe, persistent, and disabling grief. The text revision of the Diagnostic and Statistical Manual of Mental Disorders 5 (DSM-5-TR) is scheduled to include a similar but distinct diagnosis, also termed PGD. Concerns have been raised that these new diagnoses are qualitatively different from both prior proposed diagnoses for pathological grief and each other, which may affect the generalizability of findings obtained with different criteria sets.

We conducted a content overlap analysis of PGD_ICD-11, PGD_DSM-5-TR, and previous proposals for pathological grief diagnoses (i.e. PGD 2009; complicated grief (CG), PGD ICD-11 beta draft, persistent complex bereavement disorder (PCBD) per DSM-5).

Using the Jaccard's Index, we established the degree of content overlap between core and accessory symptoms of PGD_ICD-11, PGD_DSM-5-TR, and prior proposals for pathological grief diagnoses.

Main findings are that PGD_ICD-11 and PGD_DSM-5-TR showed moderate content overlap with each other and with most prior proposed diagnoses for pathological grief. PGD_ICD-11 and PGD_DSM-5-TR showed the strongest content overlap with their direct predecessors, PGD_{ICD-11 beta draft} and PCBD, respectively.

Limited content overlap between PGD_ICD-11 and PGD_DSM-5-TR and preceding criteria sets may threaten generalizability of past research on phenomenological characteristics of pathological grief to current criteria sets. Similarly, findings obtained with instruments to assess PGD_ICD-11 may not generalize to PGD_DSM-5-TR and vice versa. Researchers should aim to determine under which circumstances criteria sets for PGD yield similar or distinct characteristics. Convergence of criteria sets for PGD remains an important goal for the future.