What are the diagnostic changes for trichotillomania across DSM‑III, DSM‑III‑TR, DSM‑IV, DSM‑5, DSM‑5‑TR, ICD‑10, and ICD‑11?

Evolution of Trichotillomania Diagnostic Criteria Across DSM and ICD Versions

Trichotillomania underwent a major reclassification from an impulse control disorder in DSM-IV to an obsessive-compulsive and related disorder in DSM-5, with the most significant change being the removal of the tension-relief criterion that research had shown was not universally present in affected individuals. 1

DSM-III and DSM-III-TR Classification

• Trichotillomania was classified as an impulse control disorder not otherwise classified in DSM-III and DSM-III-TR. 2
• The diagnostic framework emphasized the impulsive nature of hair-pulling behavior during this era. 2

DSM-IV Classification and Criteria

• DSM-IV maintained trichotillomania as an impulse control disorder and defined it specifically as requiring "rising tension followed by relief or gratification" with hair pulling. 3, 4
• This tension-relief criterion proved problematic: research demonstrated that 26.7% of children with impairing hair-pulling denied experiencing rising tension or relief, suggesting the criterion was overly restrictive. 3
• Additional pediatric studies found that only one subject out of ten experienced the required tension before hair pulling and relief afterward, further challenging the validity of this diagnostic requirement. 4

DSM-5 Major Reclassification (2013)

• The American Psychiatric Association created an entirely new diagnostic chapter called "Obsessive-Compulsive and Related Disorders" that removed OCD from anxiety disorders and grouped it with trichotillomania, body dysmorphic disorder, hoarding disorder, and excoriation (skin-picking) disorder. 1
• Trichotillomania was moved from impulse control disorders into this new OCD-related chapter, reflecting evolving understanding of its phenomenology and neurobiology. 1
• The problematic tension-relief criterion appears to have been reconsidered based on accumulating evidence that it did not apply universally to affected individuals. 3, 4

DSM-5-TR Updates

• DSM-5-TR retained the classification of trichotillomania within the Obsessive-Compulsive and Related Disorders chapter without substantive structural changes. 1
• The core diagnostic framework established in DSM-5 remained intact in the text revision. 1

ICD-10 Classification

• ICD-10 contained only 11 disorder groupings in its Mental and Behavioral Disorders chapter and did not provide detailed recognition of trichotillomania as a distinct entity within an OCD-related framework. 1
• The limited granularity of ICD-10 meant trichotillomania received less specific diagnostic attention compared to later classification systems. 1

ICD-11 Major Expansion (Effective January 2022)

• The World Health Organization's ICD-11 expanded from 11 to 21 disorder groupings, achieving harmonization with DSM-5 by establishing an "Obsessive-Compulsive and Related Disorders" chapter. 1
• Trichotillomania is now recognized as an independent diagnosis within this OCD-related chapter, mirroring the DSM-5 approach. 1
• ICD-11's OCD-related chapter additionally includes Tourette syndrome, hypochondriasis, and olfactory reference syndrome beyond what DSM-5 includes. 1
• Field studies involving 928 clinicians from all WHO regions rated ICD-11 as significantly easier to use (82.5%–83.9% rated it quite or extremely easy, accurate, clear, and understandable) compared to ICD-10. 5

Critical Diagnostic Controversies

The OCD-Spectrum Question

• The relationship between trichotillomania and OCD remains contested: while DSM-5 and ICD-11 classify them together, research evidence suggests trichotillomania may be more closely related to tic disorders than to OCD from neurobiological and therapeutic standpoints. 6
• Pediatric studies found that hair-pulling children had few obsessions or compulsions aside from hair-pulling itself, with only 13% meeting full OCD criteria, challenging the OCD-spectrum conceptualization. 3
• Neuroimaging and treatment response data support a closer relationship between trichotillomania and tic disorders, particularly Tourette syndrome, than between trichotillomania and OCD. 6

Common Diagnostic Pitfalls

• Do not require the tension-relief phenomenon for diagnosis: research has definitively shown that many individuals with clinically significant, impairing hair-pulling do not experience rising tension before pulling or relief afterward. 3, 4
• Distinguish from normal developmental behaviors: diagnosis requires significant cosmetic disfigurement or functional impairment, not merely transient hair manipulation. 3
• Assess for comorbid conditions systematically: substantial psychiatric comorbidity is common, particularly overanxious disorder (60% in one pediatric sample) and family history of tics, habits, or obsessive-compulsive symptoms. 3, 4

Clinical Implications of Classification Changes

• The reclassification from impulse control disorder to OCD-related disorder has direct treatment implications, as it may influence whether clinicians consider serotonergic medications (typical for OCD) versus approaches more effective for tic disorders. 6
• The removal of overly restrictive criteria (particularly tension-relief) allows diagnosis of individuals who were previously excluded despite having clinically significant hair-pulling behavior. 3, 4
• Both DSM-5 and ICD-11 remain categorical and symptom-based without incorporating neurobiological dimensions, limiting their ability to guide biologically targeted treatment selection. 5