Prolonged Grief Disorder: Psychometric Validation of Criteria Proposed for DSM-V and ICD-11

Abstract

Holly Prigerson and colleagues tested the psychometric validity of criteria for prolonged grief disorder (PGD) to enhance the detection and care of bereaved individuals at heightened risk of persistent distress and dysfunction.

Abstract

Background

Bereavement is a universal experience, and its association with excess morbidity and mortality is well established. Nevertheless, grief becomes a serious health concern for a relative few. For such individuals, intense grief persists, is distressing and disabling, and may meet criteria as a distinct mental disorder. At present, grief is not recognized as a mental disorder in the DSM-IV or ICD-10. The goal of this study was to determine the psychometric validity of criteria for prolonged grief disorder (PGD) to enhance the detection and potential treatment of bereaved individuals at heightened risk of persistent distress and dysfunction.

Methods and Findings

A total of 291 bereaved respondents were interviewed three times, grouped as 0–6, 6–12, and 12–24 mo post-loss. Item response theory (IRT) analyses derived the most informative, unbiased PGD symptoms. Combinatoric analyses identified the most sensitive and specific PGD algorithm that was then tested to evaluate its psychometric validity. Criteria require reactions to a significant loss that involve the experience of yearning (e.g., physical or emotional suffering as a result of the desired, but unfulfilled, reunion with the deceased) and at least five of the following nine symptoms experienced at least daily or to a disabling degree: feeling emotionally numb, stunned, or that life is meaningless; experiencing mistrust; bitterness over the loss; difficulty accepting the loss; identity confusion; avoidance of the reality of the loss; or difficulty moving on with life. Symptoms must be present at sufficiently high levels at least six mo from the death and be associated with functional impairment.

Conclusions

The criteria set for PGD appear able to identify bereaved persons at heightened risk for enduring distress and dysfunction. The results support the psychometric validity of the criteria for PGD that we propose for inclusion in DSM-V and ICD-11.

Please see later in the article for Editors' Summary

Editors' Summary

Background

Virtually everyone loses someone they love during their lifetime. Grief is an unavoidable and normal reaction to this loss. After the death of a loved one, bereaved people may feel sadness, anger, guilt, anxiety, and despair. They may think constantly about the deceased person and about the events that led up to the person's death. They often have physical reactions to their loss—problems sleeping, for example—and they may become ill. Socially, they may find it difficult to return to work or to see friends and family. For most people, these painful emotions and thoughts gradually diminish, usually within 6 months or so of the death. But for a few people, the normal grief reaction lingers and becomes increasingly debilitating. Experts call this complicated grief or prolonged grief disorder (PGD). Characteristically, people with PGD have intrusive thoughts and images of the deceased person and a painful yearning for his or her presence. They may also deny their loss, feel desperately lonely and adrift, and want to die themselves.

Why Was This Study Done?

PGD is not currently recognized as a mental disorder although it meets the requirements for one given in the American Psychiatric Association's Diagnostic and Statistical Manual of Mental Disorders, 4 ^th Edition (DSM-IV) and in the World Health Organization's International Statistical Classification of Diseases and Related Health Problems, 10 ^thEdition (ICD-10) . Before PGD can be recognized as a mental disorder (and included in DSM-V and ICD-11), bereavement and mental-health experts need to agree on standardized criteria for PGD. Such criteria would be useful because they would allow researchers and clinicians to identify risk factors for PGD and to find ways to prevent PGD. They would also help to ensure that people with PGD get appropriate treatments such as psychotherapy to help them change their way of thinking about their loss and re-engage with the world. Recently, a panel of experts agreed on a consensus list of symptoms for PGD. In this study, the researchers undertake a field trial to develop and evaluate algorithms (sets of rules) for diagnosing PGD based on these symptoms.

What Did the Researchers Do and Find?

The researchers used “item response theory” (IRT) to derive the most informative PGD symptoms from structured interviews of nearly 300 people who had recently lost a close family member. These interviews contained questions about the consensus list of symptoms; each participant was interviewed two or three times during the two years after their spouse's death. The researchers then used “combinatoric” analysis to identify the most sensitive and specific algorithm for the diagnosis of PGD. This algorithm specifies that a bereaved person with PGD must experience yearning (physical or emotional suffering because of an unfulfilled desire for reunion with the deceased) and at least five of nine additional symptoms. These symptoms (which include emotional numbness, feeling that life is meaningless, and avoidance of the reality of the loss) must persist for at least 6 months after the bereavement and must be associated with functional impairment. Finally, the researchers show that individuals given a diagnosis of PGD 6–12 months after a death have a higher subsequent risk of mental health and functional impairment than people not diagnosed with PGD.

What Do These Findings Mean?

These findings validate a set of symptoms and a diagnostic algorithm for PGD. Because most of the study participants were elderly women who had lost their husband, further validation is needed to check that these symptoms and algorithm also apply to other types of bereaved people such as individuals who have lost a child. For now, though, these findings support the inclusion of PGD in DSM-V and ICD-11 as a recognized mental disorder. Furthermore, the availability of a standardized way to diagnose PGD will help clinicians identify the minority of people who fail to adjust successfully to the loss of a loved one. Hopefully, by identifying these people and helping them to avoid the onset of PGD (perhaps by providing psychotherapy soon after a death) and/or providing better treatment for PGD, it should now be possible to reduce the considerable personal and societal costs associated with prolonged grief.

Additional Information

Please access these Web sites via the online version of this summary at http://dx.doi.org/10.1371/journal.pmed.1000121.

• This study is further discussed in a PLoS Medicine Perspective by Stephen Workman

• The Dana Farber Cancer Institute has a page describing its Center for Psycho-oncology and Palliative Care Research

• The UK Royal College of Psychiatrists has a leaflet on bereavement (in English, Welsh, Urdu, and Chinese)

• The US National Cancer Institute also has information about coping with bereavement for patients and health professionals (in English and Spanish)

• MedlinePlus has links to other information about bereavement (in English and Spanish)

• The Journal of the American Medical Association has a patient page on abnormal grief

• Harvard Medical School provides a short family health guide about complicated grief

• Information on DSM-IV and ICD-10 is available