Evolution of Hoarding Disorder Diagnosis Across DSM and ICD Classifications
Hoarding Disorder did not exist as a standalone diagnosis until DSM-5 (2013) and ICD-11, representing a fundamental reclassification from being merely a symptom of other disorders to an independent diagnostic entity. 1
DSM-III and DSM-IV Era: Hoarding as a Secondary Feature
In DSM-III through DSM-IV-TR, hoarding was never a primary diagnosis but was listed as one diagnostic criterion for Obsessive-Compulsive Personality Disorder (OCPD). 2
When hoarding was extreme in DSM-IV-TR, clinicians were instructed to consider a diagnosis of OCD, and could diagnose both OCPD and OCD if criteria for both were met—but hoarding itself remained subordinate to these other diagnoses. 2
Hoarding was conceptualized as a symptom dimension within OCD, grouped with contamination/cleaning, harm/checking, forbidden thoughts/mental rituals, and symmetry/ordering dimensions. 3, 1
This classification persisted despite accumulating evidence that compulsive hoarding frequently occurred independently from OCD and OCPD, with distinct clinical characteristics including different onset patterns, course, degree of insight, and treatment responses. 2, 4
DSM-5 (2013): Creation of Hoarding Disorder
DSM-5 established Hoarding Disorder as a new, independent diagnosis within a newly created "Obsessive-Compulsive and Related Disorders" chapter, fundamentally changing its nosological status. 1
The new chapter grouped OCD with body dysmorphic disorder, trichotillomania (hair-pulling), hoarding disorder, and excoriation (skin-picking) disorder—moving OCD itself from the anxiety disorders chapter where it had resided since DSM-III. 3, 1
Core diagnostic criteria require: (1) persistent difficulty discarding possessions due to strong urges to save items, (2) accumulation that creates clutter interfering with the intended use of living spaces regardless of actual value, (3) symptoms that are time-consuming (typically >1 hour per day) and cause clinically significant distress or functional impairment. 1, 5
The diagnosis explicitly distinguishes hoarding from OCD by noting that hoarding symptoms lack the ego-dystonic quality of OCD obsessions and instead involve attachment to possessions themselves—the primary motivation differs fundamentally between the two conditions. 5
DSM-5 includes exclusion criteria stating that hoarding should not be diagnosed when symptoms are better explained by another mental disorder or attributable to physiological effects of substances or another medical condition. 1
DSM-5-TR: Continuity Without Major Changes
DSM-5-TR maintained the diagnostic criteria and classification structure established in DSM-5 without substantive modifications to Hoarding Disorder. 1
The text revision preserved the insight specifier framework and the placement within Obsessive-Compulsive and Related Disorders. 1
ICD-10: Absence of Hoarding Disorder
ICD-10 did not include Hoarding Disorder as a distinct diagnostic entity. 3
The ICD-10 Mental and Behavioral Disorders chapter contained only 11 disorder groupings, and hoarding was not separately classified. 3
ICD-11 (2022): Alignment with DSM-5
ICD-11 mirrors DSM-5 by establishing an "Obsessive-Compulsive and Related Disorders" chapter that includes Hoarding Disorder as an independent diagnosis, effective January 1,2022. 3, 1
The ICD-11 chapter expanded to 21 disorder groupings compared to 11 in ICD-10, with harmonization between WHO and American Psychiatric Association classifications being an explicit goal. 3
ICD-11 defines Hoarding Disorder as "characterized by accumulation of possessions due to excessive acquisition of possession or difficulties discarding them, regardless of their actual value." 3
ICD-11's Obsessive-Compulsive and Related Disorders chapter additionally includes Tourette syndrome, hypochondriasis, and olfactory reference syndrome beyond what DSM-5 includes. 3, 1
Key Diagnostic Pitfalls to Avoid
Do not diagnose normal collecting behavior as Hoarding Disorder—collectors typically maintain organization, derive pleasure from their collections, and do not experience functional impairment; the diagnosis requires >1 hour per day of symptom time-consumption plus substantial distress or functional impairment. 1, 6
Do not misdiagnose Hoarding Disorder with poor insight as a psychotic disorder—beliefs in hoarding are restricted to hoarding themes (attachment to possessions) and lack hallucinations, disorganized speech, or negative symptoms characteristic of psychotic disorders. 1
Recognize that hoarding in the context of dementia (especially frontotemporal type), schizophrenia, or Diogenes syndrome represents a different clinical entity requiring evaluation of the primary underlying condition. 7