Diagnostic Strengths and Weaknesses of DSM-5-TR and ICD-11 for Hoarding Disorder
Direct Answer
Both DSM-5-TR and ICD-11 provide reliable diagnostic frameworks for Hoarding Disorder with clear categorical criteria, but both systems lack neurobiological grounding and dimensional assessment tools, limiting their ability to guide biologically-targeted treatments or capture the full spectrum of hoarding severity.
Classification Evolution and Recognition
Establishment as Independent Diagnosis
DSM-5 (2013) created Hoarding Disorder as a standalone diagnosis within the newly established "Obsessive-Compulsive and Related Disorders" chapter, moving it away from being merely a symptom dimension of OCD 1.
ICD-11 (effective January 2022) aligned with DSM-5 by introducing its own "Obsessive-Compulsive and Related Disorders" chapter that recognizes Hoarding Disorder as an independent diagnosis, whereas ICD-10 had completely omitted hoarding as a distinct entity 1.
This reclassification reflects accumulating evidence that hoarding differs substantially from OCD in clinical characteristics including onset, course, degree of insight, and treatment responses 2.
The WHO expanded its mental disorders chapter from 11 to 21 groupings to achieve harmonization between ICD-11 and DSM-5 classifications 1.
Strengths of Both Systems
Clear Diagnostic Boundaries
Both systems define core features consistently: accumulation of possessions due to excessive acquisition or difficulty discarding them, regardless of actual value, resulting in clutter that obstructs living spaces 1.
The proposed DSM-5 criteria appear to accurately define the disorder with preliminary studies suggesting they are reliable 3.
Field studies demonstrate that collectors are unlikely to be inappropriately pathologized because the diagnostic criteria successfully differentiate pathological hoarding from normative collecting through requirements for significant clutter and functional impairment 4.
Clinical Utility and Usability
ICD-11 field studies involving 928 clinicians from all WHO regions showed 82.5%–83.9% rated the system as quite or extremely easy to use, accurate, clear, and understandable, representing significantly higher perceived usability compared with ICD-10 5.
Field studies reported higher diagnostic accuracy and clinical utility for ICD-11 versus ICD-10 across multiple disorder categories 5.
Epidemiological Validation
The DSM-5 criteria have been validated in epidemiological studies, with a weighted prevalence of 1.5% (95% CI 0.7-2.2) identified in a two-wave study of 1,698 adults 6.
Those meeting diagnostic criteria showed clear associations with substantial adversity, including physical health impairment (52.6%), comorbid mental disorders (58%), and benefit claims (47.4%), supporting the clinical significance threshold 6.
Weaknesses of Both Systems
Absence of Neurobiological Dimensions
Both DSM-5-TR and ICD-11 lack neurobiological dimensions, relying solely on self-reported or clinically observable symptoms rather than underlying pathophysiology, which limits biologically-targeted treatment planning 5.
Neuroimaging studies have found specific changes in brain structure and function in patients with hoarding symptoms compared to those with non-hoarding OCD, yet neither classification system incorporates these biological markers 2.
The absence of biological grounding produces diagnostically heterogeneous categories that cannot guide treatment selection based on mechanisms, reducing the potential for precision interventions 5.
Lack of Dimensional Assessment
Both systems remain primarily categorical, classifying mental phenomena based on symptoms rather than incorporating dimensional severity measures that could better capture the spectrum of hoarding behavior 7.
Changes from ICD-10 to ICD-11 were relatively modest, with no paradigm shift toward biologically informed classification 7.
Neither system adequately addresses the biological heterogeneity within the diagnostic category 7.
Limited Specifier Options
ICD-11 does not include insight specifiers or severity gradations that are present in DSM-5-TR for other obsessive-compulsive related disorders, potentially overlooking clinically important subtypes 5.
The WHO Working Group suggested that poor insight and severe domestic squalor may be considered as specifiers for hoarding disorder in ICD-11, but these have not been formally incorporated 8.
Methodological Limitations of Validation Studies
Selection bias may have inflated ICD-11 performance because clinicians favorable toward ICD-11 were more likely to enroll in field studies, especially those conducted online with self-registration 5.
Vignette-based designs used prototypical cases that may not capture the complexity of real-world presentations, limiting the generalizability of the findings 5.
Participants' awareness of being studied could alter their diagnostic behavior, meaning study results may not reflect routine clinical decision-making 5.
Clinical Pitfalls and Practical Considerations
Distinguishing from Normative Collecting
Collectors differ from those with Hoarding Disorder in being more focused in acquisitions (confining accumulations to a narrow range of items), more selective (planning and purchasing only pre-determined items), more likely to organize possessions, and less likely to accumulate excessively 4.
The resulting clutter and impairment are minimal in collectors and ultimately insufficient to garner a Hoarding Disorder diagnosis 4.
Treatment Implications
Strategies for treatment of Hoarding Disorder have not been standardized, with psychological treatment using cognitive behavioral therapy techniques showing only modest effects 2.
The categorical nature of both systems without biological grounding limits the ability to develop targeted pharmacological interventions based on underlying mechanisms 5.
Access to Care
- Individuals with Hoarding Disorder are more likely to report lifetime use of mental health services, although access in the past year was less frequent, suggesting barriers to ongoing care 6.
Recommendations for Diagnostic Approach
Algorithmic Assessment Strategy
Confirm core features: persistent difficulty discarding possessions AND accumulation resulting in clutter that obstructs use of living areas 1.
Assess functional impairment: verify clinically significant distress or impairment in social, occupational, or other important areas of functioning 3.
Rule out normative collecting: evaluate whether acquisitions are focused, selective, organized, and non-excessive 4.
Document associated features: assess for physical health conditions, comorbid mental disorders, and degree of insight, as these affect prognosis and treatment planning 6, 8.
Consider ecological validity: recognize that both DSM-5-TR and ICD-11 criteria were validated primarily in research settings and may require clinical judgment in complex real-world presentations 5.