Reliability and Validity of the Trichotillomania Dimensional Scale (TTM-D)

Publication date: Available online 15 August 2018Source: Journal of Obsessive-Compulsive and Related DisordersAuthor(s): Jacqueline E. Cheyne, Andrea del Pozo de Bolger, Bethany M. WoottonAbstractTrichotillomania (TTM) is characterized by repetitive hair pulling resulting in hair loss. The Trichotillomania Dimensional Scale (TTM-D) is a newly developed DSM-5 scale that aims to assess the symptoms of TTM dimensionally. The aim of this current study was to examine the psychometric properties of the TTM-D in a sample of 483 participants. Principal Component Analysis indicated a single factor structure of the TTM-D. Internal consistency and test retest reliability was high (α =.89 and r = .91 respectively). The TTM-D demonstrated excellent convergent validity with the Massachusetts General Hospital Hair Pulling Scale (MGH-HPS; rs = .90) and divergent validity with the Depression Anxiety and Stress Scale (DASS-21; rs = .45). Further, the TTM-D demonstrated equivalence between online and pen-and-paper administrations (rs= .93). The findings suggest that the psychometric properties of TTM-D are sound and well supported within a community sample.
Source: Journal of Obsessive Compulsive and Related Disorders - Category: Psychiatry Source Type: research