Aarhus Prolonged Grief Disorder Scale (A-PGDs)

Abstract

The Aarhus Prolonged Grief Disorder Scale (A-PGDs) is a psychometrically validated self-report assessment instrument formulated to operationalize the diagnostic criteria for Prolonged Grief Disorder (PGD) as defined concurrently by the World Health Organization’s International Classification of Diseases, 11th Revision (ICD-11) and the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR). Developed by Maja O’Connor and colleagues in 2023, the instrument addresses a critical diagnostic challenge: reconciling the distinct yet overlapping symptom criteria, temporal benchmarks, and impairment parameters established by the two major psychiatric nosologies. Comprising 20 primary items and four secondary functional impairment domain queries, the scale utilizes a 5-point Likert scale (ranging from 1 = “Not at all” to 5 = “Overwhelmingly”) alongside dichotomous (Yes/No) clinical gating questions. Psychometric evaluation via exploratory structural equation modeling (ESEM) and confirmatory factor analysis (CFA) reveals robust structural validity, resolving into core separation distress and associated cognitive, emotional, and behavioral symptom dimensions. The scale exhibits exceptional internal consistency, with Cronbach’s alpha coefficients of α = .88 for the ICD-11 symptom set and α = .90 for the DSM-5-TR symptom set. Test-retest reliability across assessment intervals demonstrates temporal stability (r ≥ .59 to .72). The A-PGDs provides researchers and clinicians with a psychometrically sound, standardized tool for epidemiological surveillance, clinical diagnosis, and outcome monitoring in bereaved adult populations.

Keywords

Prolonged Grief Disorder, A-PGDs, Bereavement, ICD-11, DSM-5-TR, Complicated Grief, Psychometrics, Separation Distress, Functional Impairment, Exploratory Structural Equation Modeling

Authors

The Aarhus Prolonged Grief Disorder Scale was developed through a multi-institutional collaboration led by researchers specializing in trauma, bereavement, and quantitative psychometrics:

• Maja O’Connor, Ph.D. (Corresponding Author) — Professor and Head of the Unit for Bereavement Research, Department of Psychology, Aarhus University, Aarhus, Denmark. Email: [email protected].
• Maria Louison Vang, Ph.D. — National Center for Psychotraumatology, Department of Psychology, University of Southern Denmark, Odense, Denmark (ORCID: 0000-0001-7031-4070).
• Mark Shevlin, Ph.D. — Professor of Psychology, School of Psychology, Ulster University, Derry, Northern Ireland.
• Ask Elklit, Ph.D. — Professor of Clinical Psychology, National Center for Psychotraumatology, Department of Psychology, University of Southern Denmark, Odense, Denmark.
• Katrine B. Komischke-Konnerup, Ph.D. — Unit for Bereavement Research, Department of Psychology, Aarhus University, Aarhus, Denmark.
• Marie Lundorff, Ph.D. — Unit for Bereavement Research, Department of Psychology, Aarhus University, Aarhus, Denmark (ORCID: 0000-0003-0162-5750).
• Richard A. Bryant, Ph.D. — Scientia Professor of Psychology, School of Psychology, University of New South Wales, Sydney, Australia.

Purpose

The overarching objective of the Aarhus Prolonged Grief Disorder Scale (A-PGDs) is to establish a unified, standardized, and clinically actionable self-report instrument capable of operationalizing Prolonged Grief Disorder under both the ICD-11 and the DSM-5-TR diagnostic frameworks. Prior to the formal codification of PGD in these diagnostic systems, the bereavement research field relied upon a disparate array of instruments evaluating “complicated grief” or “traumatic grief,” such as the Inventory of Complicated Grief (ICG; Prigerson et al., 1995) and the Prolonged Grief-13 (PG-13; Prigerson et al., 2009). Although these early measures were instrumental in validating pathological grief as a discrete clinical entity, they do not align perfectly with the specific diagnostic thresholds, criterion structures, and exclusionary rules codified in the ICD-11 and DSM-5-TR.

The diagnostic criteria of ICD-11 and DSM-5-TR diverge in meaningful ways:

• Diagnostic Thresholds and Item Composition: ICD-11 requires persistent and pervasive longing for the deceased or persistent preoccupation with the deceased, accompanied by at least one of ten additional emotional distress indicators, persisting for an atypical duration (typically at least 6 months post-loss) that exceeds cultural norms. In contrast, DSM-5-TR establishes a criterion requiring intense yearning/longing or preoccupation, coupled with at least three of eight accessory cognitive, emotional, or behavioral symptoms, with a minimum duration criterion of at least 12 months post-loss for adults.
• Associated Symptoms: Specific items are prioritized differently across the manuals. For instance, self-blame is included in ICD-11 descriptions, whereas DSM-5-TR highlights intense emotional pain, identity disruption, feeling that life is meaningless, or marked avoidance of reminders.

The A-PGDs bridges this nosological divide by organizing items so that investigators and clinicians can assess both algorithms within a single questionnaire. In clinical settings, the scale serves as a comprehensive diagnostic screening tool to identify individuals who have transitioned from adaptive grief to a debilitating, unresolving condition requiring specialized therapeutic intervention (such as Prolonged Grief Disorder Therapy). In research contexts, the scale enables cross-paradigm comparisons, allowing researchers to evaluate how diagnostic concordance, prevalence rates, and prognostic trajectories differ between the ICD-11 and DSM-5-TR frameworks within the same empirical cohorts.

Psychological Construct

The A-PGDs measures the psychopathological construct of Prolonged Grief Disorder, an enduring, disabling bereavement reaction that deviates from standard cultural, religious, and social expectations. The construct is multi-faceted, comprising affective, cognitive, behavioural, and identity-related disturbances that cluster into two principal domains: Core Separation Distress and Associated Symptoms.

Core Separation Distress

Separation distress represents the pathognomonic core of prolonged grief. It is characterized by severe, unrelenting yearning, pining, and an intense longing for the deceased individual. This dimension includes:

• Intrusive Preoccupation: The bereaved individual experiences frequent, non-volitional thoughts, memories, or internal images of the deceased that interfere with everyday functioning and focus.
• Pervasive Emotional Sorrow: Sustained pangs of intense emotional pain, sadness, and anguish that do not remit over time.
• Cognitive Non-Acceptance and Disbelief: A profound difficulty accepting the finality and reality of the death, often accompanied by an ongoing feeling that the loss did not occur or that the deceased will return.

Associated Cognitive, Affective, and Behavioral Alterations

The associated symptom complex reflects the downstream collateral damage caused by unintegrated loss on emotional processing and self-regulation:

• Identity Disruption: A perceived loss of a fundamental part of oneself (e.g., feeling as though a part of the self died with the deceased), accompanied by an inability to envision an autonomous future without the lost individual.
• Affective Constriction and Emotional Numbing: An inability to experience positive affect, contentment, or joy, often accompanied by general subjective deadness or emotional detachment from others.
• Existential Meaninglessness and Hopelessness: The belief that life has lost its purpose, value, or coherence following the loss.
• Avoidance Behavior: Active, continuous avoidance of external reminders (places, objects, activities, conversations) and internal triggers (thoughts, feelings, memories) related to the reality of the loss.
• Social Withdrawal and Loneliness: Marked detachment from significant others, severe subjective isolation, and difficulty engaging productively in interpersonal relationships or social roles.
• Antagonistic and Maladaptive Cognitions: Persistent feelings of anger, bitterness over the loss, and pervasive guilt or self-blame regarding the death or its circumstances.

Functional Impairment and Contextual Anchors

A central feature of the PGD construct as operationalized by the A-PGDs is clinical functional impairment. Psychological distress must directly compromise the individual’s occupational, academic, domestic, or social capacities. Furthermore, the construct includes explicit contextual boundaries: the grief response must exceed normative reactions within the individual’s specific cultural, social, and religious context, and must persist across defined temporal thresholds (at least 6 months under ICD-11; 12 months under DSM-5-TR).

Theoretical Framework

The operationalization of prolonged grief within the A-PGDs rests upon three foundational psychological models: Attachment Theory, the Cognitive-Behavioral Model of Complicated Grief, and the Dual Process Model of Coping with Bereavement.

Attachment Theory

Originating with John Bowlby (1980) and expanded by Mary Ainsworth, attachment theory posits that humans possess an innate psychobiological behavioral system designed to maintain proximity to primary attachment figures. The death of an attachment figure disrupts this system, triggering intense search and protest behaviors manifested as separation distress, yearning, and longing.

In typical bereavement, the attachment system gradually adjusts through cognitive reorganization, accommodating the physical absence of the attachment figure into revised internal working models of the self and the social world. In PGD, however, this accommodation process becomes blocked. The proximity-seeking behaviors become chronic, trapping the individual in a state of ongoing separation distress where the reality of the death cannot be integrated into long-term autobiographical memory networks.

Cognitive-Behavioral Model of Complicated Grief

Developed by Boelen, van den Hout, and van den Bout (2006), the cognitive-behavioral model argues that pathological grief is sustained by three interrelated mechanisms:

1. Insufficient Integration of the Loss: The reality of the death is not fully integrated into autobiographical memory, leading to continuous feelings of disbelief, shock, and intrusive trauma-like re-experiencing.
2. Maladaptive Appraisals: Catastrophic cognitions regarding one’s grief reactions (e.g., “If I let go of this pain, I am betraying my loved one,” or “I cannot survive without them”) generate profound guilt, self-blame, and secondary anxiety.
3. Avoidant Coping Strategies: Both cognitive avoidance (emotional numbing, thought suppression) and behavioral avoidance (refusing to visit gravesites or interact with shared social contacts) prevent exposure to disconfirming information and hinder emotional habituation, sustaining the disorder over time.

The Dual Process Model

The Dual Process Model of Coping with Bereavement, formulated by Margaret Stroebe and Henk Schut (1999), proposes that healthy adaptation requires an adaptive oscillation between loss-oriented coping (processing grief, crying, looking at photographs) and restoration-oriented coping (attending to life changes, mastering new tasks, forging new relationships). In PGD, this regulatory oscillation breaks down. Bereaved individuals become trapped almost entirely in loss-oriented rumination or engage in severe, maladaptive avoidance of restoration activities, resulting in pervasive functional impairment across occupational and interpersonal domains.

Validity

The psychometric validation of the A-PGDs (O’Connor et al., 2023) evaluated construct, concurrent, predictive, and structural validity across a large sample of bereaved adults in Denmark.

Construct and Structural Validity

Construct validity was established through factor analytic modeling. Using exploratory structural equation modeling (ESEM) and confirmatory factor analysis (CFA), the researchers evaluated the internal structural architecture of both the ICD-11 and DSM-5-TR symptom sets. Across both classification systems, models separating core separation distress from secondary associated symptom factors exhibited superior structural fit relative to unidimensional formulations. The factor structures clearly distinguished between the primary attachment-related longing/yearning criteria and the downstream affective and cognitive complications.

Concurrent and Predictive Validity

Empirical evidence for concurrent and predictive validity was supported by differential associations with external psychological variables:

• Predictive Pathways: In longitudinal regression analyses, baseline PGD symptoms robustly predicted core separation distress at follow-up.
• Divergent Predictors: Depressive symptoms at baseline exclusively predicted associated symptoms (such as emotional numbing, identity confusion, and feelings of meaninglessness), while failing to predict primary core separation distress. This supports the nosological independence of prolonged grief from major depressive disorder.
• Functional Impairment Relationships: Structural equation models showed that the associated symptoms factor was the sole significant direct predictor of self-reported functional impairment across domestic, occupational, and social domains. Core separation distress alone did not drive functional decline unless accompanied by elevated associated cognitive-affective symptoms.

Content and Face Validity

Item generation for the A-PGDs involved a multi-stage review process combining verbatim diagnostic criteria from the ICD-11 and DSM-5-TR with items from validated legacy scales, notably the Inventory of Complicated Grief-Japanese Version (Ito et al., 2012) and the Prolonged Grief Disorder-13 (Prigerson et al., 2009). The preliminary items underwent cognitive debriefing and refinement within focus groups composed of bereaved adults and bereavement clinicians, ensuring high face validity, linguistic clarity, and contextual sensitivity.

Reliability

The A-PGDs demonstrates strong reliability across indices of internal consistency and temporal stability.

Internal Consistency

The scale shows strong internal consistency across both diagnostic operationalizations:

• ICD-11 PGD Subscale: Demonstrated a Cronbach’s alpha of α = .88, indicating high internal coherence among the items reflecting the WHO diagnostic guidelines.
• DSM-5-TR PGD Subscale: Yielded a Cronbach’s alpha of α = .90, reflecting strong consistency across the eight accessory criteria and core symptoms defined by the American Psychiatric Association.

Test-Retest Reliability and Temporal Stability

Temporal stability was evaluated in a longitudinal subsample of bereaved participants who completed the instrument across successive testing intervals. Overall test-retest reliability was robust (p < .001 for all items), with correlation coefficients across all individual items meeting or exceeding r ≥ .59.

A notable psychometric pattern emerged regarding item stability:

• Core Symptom Cluster Stability: Items loading onto the core separation distress dimension (yearning, persistent preoccupation, and non-acceptance) exhibited higher temporal stability across both ICD-11 and DSM-5-TR criteria, with test-retest coefficients consistently reaching r ≥ .72 (with the sole exception of the self-blame item).
• Associated Symptom Stability: Items measuring associated symptoms (e.g., emotional numbing, social detachment, anger) yielded slightly lower, though still solid, stability estimates (ranging between r = .59 and r = .71). This reflects the greater situational variability of accessory emotional states compared to core separation distress.

Factor Analysis

The latent dimensionality of the A-PGDs was evaluated using exploratory structural equation modeling (ESEM) and confirmatory factor analysis (CFA) to determine how well the scale items fit the diagnostic structures of the ICD-11 and DSM-5-TR.

ICD-11 Factor Modeling

For the ICD-11 symptom configuration, structural models ranging from 1 to 4 factors were evaluated:

• Models 2, 3, and 4: All multi-factor models demonstrated acceptable residual error profiles, yielding Standardized Root Mean Square Residual (SRMR) and Root Mean Square Error of Approximation (RMSEA) values below the conventional .08 threshold.
• Fit Indices (CFI/TLI): Only Model 4 achieved acceptable comparative fit, with both the Comparative Fit Index (CFI) and Tucker-Lewis Index (TLI) exceeding .90.
• Parsimony and Information Criteria: Despite the improved incremental fit of the 4-factor structure, the Bayesian Information Criterion (BIC) increased substantially (ΔBIC = 14.2). This indicated that the additional statistical parameters did not outweigh the loss of parsimony, suggesting that a simpler two-factor structure (distinguishing core separation distress from associated emotional-behavioral symptoms) provides a more practical and generalizable framework for the ICD-11 criteria.

DSM-5-TR Factor Modeling

For the DSM-5-TR symptom architecture, systematic improvements in model fit were observed as the latent dimensionality increased from unidimensional to multidimensional structures:

• Error Metrics: Models 2 through 4 all exhibited acceptable fit according to SRMR and RMSEA values (< .08).
• Comparative Indices: Both Model 3 and Model 4 satisfied standard fit thresholds for the CFI and TLI (> .90).
• Model Comparison: The four-factor solution demonstrated superior overall fit. Unlike the ICD-11 analysis, the reduction in RMSEA was statistically significant (ΔRMSEA = 0.019), and the Bayesian Information Criterion demonstrated that the increased model precision justified the additional parameters (ΔBIC = 10.9). These findings support a differentiated multidimensional structure for the DSM-5-TR criteria, distinguishing separation distress, cognitive appraisals, emotional numbing/avoidance, and identity disruption.

Instrument / Measurement Tool

The Aarhus Prolonged Grief Disorder Scale is structured as an integrated clinical assessment battery:

• Test Type: Standardized self-report psychiatric rating scale.
• Target Population: Bereaved adults (aged 18 years and older).
• Available Languages: Danish and English (validated forward- and back-translations).
• Item Count: 20 numbered items, including multi-part functional impairment criteria (17, 17a–17d) and diagnostic gating items (18, 19, 20).
• Response Format:
  • Symptom Items (Items 1–17): Rated on a 5-point Likert scale:
    • 1 = Not at all
    • 2 = A little
    • 3 = To some extent
    • 4 = Very much
    • 5 = Overwhelmingly
  • Functional Impairment Sub-items (Items 17 Frequency, 17a–17d): Dichotomous categorical format (Yes / No).
  • Contextual & Temporal Criteria (Items 18, 19, 20): Dichotomous categorical format (Yes / No).
• Diagnostic Classification Rules:
  • ICD-11 Diagnostic Algorithm: Requires endorsing at least one core symptom (Item 1 or Item 2) at a clinically significant level (typically rated ≥ 3 or ≥ 4 depending on intended sensitivity/specificity), accompanied by persistent emotional distress, a positive endorsement of daily functional impairment (Item 17 ≥ 2 plus Item 17 follow-up = Yes, with endorsement on 17a, 17b, 17c, or 17d), cultural deviation (Item 18 or 19 = Yes), and a minimum symptom duration of at least 6 months (Item 20 = Yes).
  • DSM-5-TR Diagnostic Algorithm: Requires endorsing at least one core criterion (Item 1 or Item 2), along with clinical elevation across at least three accessory cognitive/affective symptoms (selected from Items 6, 8, 9, 10, 11, 14, 15, 16), pervasive everyday functional impairment (Item 17 series = Yes), cultural non-normativeness (Item 18 or 19), and symptom persistence for at least 12 months post-loss (assessed clinically or via supplementary timeframe gating).
• Continuous Scoring: For dimensional research, items can be summed to generate total symptom severity scores or separate composite scores for the ICD-11 and DSM-5-TR symptom sets.

Permissions & Fee and Test Year

The Aarhus Prolonged Grief Disorder Scale was published in 2023 by Maja O’Connor and co-authors in the Journal of Affective Disorders. The instrument is distributed under the Creative Commons Attribution 4.0 International License (CC BY 4.0). As an open-access psychometric instrument, it may be utilized free of charge for academic, research, teaching, and clinical purposes without prior written authorization, provided that appropriate bibliographic credit is attributed to the original authors. Commercial redistribution or clinical incorporation into proprietary closed software systems requires consultation with the copyright holders and primary author (Unit for Bereavement Research, Aarhus University).

References

• Boelen, P. A., van den Hout, M. A., & van den Bout, J. (2006). A cognitive-behavioral conceptualization of complicated grief. Clinical Psychology: Science and Practice, 13(2), 109–128. https://doi.org/10.1111/j.1468-2850.2006.00013.x
• Bowlby, J. (1980). Attachment and loss: Vol. 3. Loss: Sadness and depression. Basic Books.
• Ito, M., Nakajima, S., Fujisawa, D., Miyashita, Y., Konishi, S., Akechi, T., & Holland, J. C. (2012). The Inventory of Complicated Grief-Japanese version: Reliability and validity study. Psychiatry and Clinical Neurosciences, 66(2), 159–166. https://doi.org/10.1111/j.1440-1819.2011.02310.x
• O’Connor, M., Vang, M. L., Shevlin, M., Elklit, A., Komischke-Konnerup, K. B., Lundorff, M., & Bryant, R. A. (2023). Development and validation of the Aarhus Prolonged Grief Disorder Scale (A-PGDs). Journal of Affective Disorders, 342, 199–205. https://doi.org/10.1016/j.jad.2023.09.006
• Prigerson, H. G., Maciejewski, P. K., Reynolds, C. F., Bierhals, A. J., Newsom, J. T., Fasiczka, A., Frank, E., Doman, J., & Miller, M. (1995). Inventory of Complicated Grief: A scale to measure maladaptive symptoms of loss. Psychiatry Research, 59(1–2), 65–79. https://doi.org/10.1016/0165-1781(95)02757-2
• Prigerson, H. G., Horowitz, M. J., Jacobs, S. C., Parkes, C. M., Aslan, M., Goodkin, K., Raphael, B., Marwit, S. J., Wortman, C., Neimeyer, R. A., Bonanno, G. A., Block, S. D., Kissane, D., Boelen, P., Maercker, A., Litz, B. T., Johnson, J. G., First, M. B., & Maciejewski, P. K. (2009). Prolonged grief disorder: Psychometric properties of an interview-based measure. PLoS Medicine, 6(8), Article e1000121. https://doi.org/10.1371/journal.pmed.1000121
• Stroebe, M., & Schut, H. (1999). The dual process model of coping with bereavement: Rationale and description. Death Studies, 23(3), 197–224. https://doi.org/10.1080/074811899201046

13. Items of the Scale (Questionnaire)