Development and validation of first clinical diagnostic interview for assessing Prolonged Grief Disorder (PGD) with the ICD 11 and DSM 5 Tr criteria.

Development and validation of first clinical diagnostic interview for assessing Prolonged Grief Disorder (PGD) with the ICD 11 and DSM 5 Tr criteria.

Background: With WHO's introduction of PGD in the ICD 11, which will be implemented in Health Services worldwide from January 2022, there is a need to accurately diagnose people with ICD-11PGD (PGD caseness) with a valid structured clinical interview.

With ICD-11 a slightly different set of symptoms for PGD is defined as the gold standard for PGD. This standard will be used for diagnosing and understanding PGD in future research and health service. ICD-11 aims to be descriptive, e.g. provides a support for the clinicians to identify PGD by describing common reactions and symptoms of this disorder, but there is still a need to evaluate the validity of these criteria. Strict diagnostic criteria with defined numbers, combinations, and intensity of symptoms (e.g. for the use in research) are not yet defined in ICD-11 and no structured clinical interview that measure ICD-11 or the upcoming DSM 5 tr PGD has yet been developed and validated for this purpose. This means that the field currently stand without reliable ways to classify accurately who has PGD diagnosis and who has not. Without such constructs, PGD is not possible to identify, and ultimately to treat, in a validated and reliable way.

There is therefore a need to develop accurate tests that measure ICD 11 PGD, both in a structured clinical interview for use in direct meetings between patients and health service professionals and in relation to a self-report scale. The investigators already developed the Aarhus PGD scale but still need a structured clinical interview.

Aim: In this project we will

1. Develop and validate the first structured, clinical interview for ICD-11 PGD and DSM-5 Tr PGD
2. Identify a valid clinical cut-off for diagnostic PGD on The Aarhus PGD Scale.

Method:

Based on the ICD-11 and DSM 5 Tr PGD criteria and our work with the self-report scale above the investigators will develop a structured, clinical interview, The Aarhus PGD Interview, in line with the strategy used in SCID-I interviews [6]. This study will examine the content validity, the concurrent validity, the test-retest reliability and the inter-rater reliability of this interview.

After the Aarhus PGD Interview is validated, this study will compare the participant's scores on the Aarhus PGD Scale for ICD 11 and DSM 5 Tr PGD with the clinical interview as the gold standard. This will allow investigating the diagnostic test accuracy of the ICD-11 PGD scale, and to identify a valid clinical cut-off on this scale.

Perspectives: The main aim of this study is to develop and validate the first structured, clinical interview for ICD 11 and DSM 5 Tr PGD. It will provide reliable constructs to separate PGD from other, trans-diagnostic forms of complicated grief reactions such as PTSD, depression and anxiety following a loss. The ability to identify who actually has a diagnosis of PGD and are in need of treatment is crucial to be able to allocate health benefits as efficient and helpful as possible. It is also crucial in identifying the vast majority of bereaved people with normal grief reactions, and to reduce the risk of pathologizing healthy grief, which is a concern brought on by the introduction of PGD as a diagnostic entity

Inclusion Criteria:

• Bereaved by the loss a loved one to death minimum 6 month ago
• 18 years or above
• The grief is still (more or less) affecting function/everyday life

Exclusion Criteria:

• Bereaved by other losses than a loved person (e.g., pet, divorce)
• 17 years or younger
• Less than 6 month ago since the loss.

Bereaved (Danish) persons who lost a loved one minimum 6 month ago.