Abstract
Background
Trichotillomania (TTM) is a psychiatric disorder that leads to significant hair loss, distress, and impairment. Few validated measures exist to assess TTM, and psychometric research examining these tools is sparse. This study evaluated the psychometric properties of commonly used TTM severity measures and extended prior research by including hair loss severity ratings in our analyses.
Methods
Participants included 91 adults (92.3% Female; M age = 35.0) with TTM who completed baseline assessments as part of a randomized clinical trial of psychotherapy for TTM. TTM measures included the Massachusetts General Hospital Hairpulling Scale (MGH-HS) and National Institute of Mental Health Trichotillomania Severity Scale (NIMH-TSS). Independent evaluators rated photos of participants’ most severely affected pulling sites using a one-item hair loss severity scale.
Results
Results showed mixed psychometric properties for TTM measures. The MGH-HS showed acceptable internal consistency (alpha = 0.83; omega = 0.89), while the NIMH-TSS had lower internal consistency (alpha = 0.52; omega = 0.73). Both the MGH-HS and NIMH-TSS demonstrated low test-retest reliability. Total scores on the MGH-HS and NIMH-TSS were not associated with hair loss severity.
Conclusions
Given these findings, it is imperative to develop new, psychometrically-sound TTM measures. These results also emphasize the importance of a multi-method approach to TTM assessment. In addition to self-report and clinician-administered measures, hair loss severity ratings may offer valuable information as part of a comprehensive assessment of TTM.
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This work was supported by the National Institute of Mental Health of the National Institutes of Health under award number R01MH080966.
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Ms. Barber, Mr. Bauer, Dr. Saunders, Dr. Compton, and Dr. Franklin declare that they have no conflict of interest. Dr. Woods receives book royalties from Oxford University Press and Guilford Press. Dr. Twohig has books on trichotillomania and ACT with New Harbinger and Oxford University Press, has received honorarium for talks on ACT and trichotillomania, and has received donations from the Huntsman Foundation for his research on trichotillomania.
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Data analyzed in this study were collected as part of a randomized clinical trial examining the efficacy of psychotherapy for adults with TTM. All procedures performed in studies involving human participants were in accordance with the ethical standards of the Institutional and/or National Research Committee and with the 1964 Helsinki Declaration and its later amendments or comparable ethical standards. The data collection procedures for the trial were approved by Institutional Review Boards at both the University of Wisconsin-Milwaukee and Texas A&M University.
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Barber, K.E., Woods, D.W., Bauer, C.C. et al. Psychometric Properties of Trichotillomania Severity Measures. Cogn Ther Res 48, 18–29 (2024). https://doi.org/10.1007/s10608-023-10406-4
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DOI: https://doi.org/10.1007/s10608-023-10406-4