Where on the obsessive impulsive–compulsive spectrum does hair-pulling sisorder belong?

Abstract

Objective. Hair-pulling disorder (HPD) is a putative obsessive–compulsive spectrum disorder, but proper categorization is challenging. Distinct subgroups of HPD may exist, depending on the primary motivation in the act of pulling. Two notable proposed subgroups are “relief pullers” (pulling primarily to reduce anxiety— a “compulsive” subgroup) and “pleasure/gratification pullers” (pulling primarily for reward— an “impulsive” subgroup) which we sought to examine in order to contribute to conversations on the categorization of HPD. Methods. A total of 111 HPD subjects (mean age 33.7 ± 10.7 [range 18–61] years; 87.4% female) were included. Demographic and clinical characteristics were compared between subgroups (pleasure: n = 51; relief: n = 60); and cognitive performance where data were available (n = 29 per group) and 32 matched healthy controls. Results. No significant demographic differences were noted between groups. Pleasure pullers were significantly more conscious of their pulling. Response inhibition and set shifting deficits were noted in HPD versus controls; however, pleasure and relief pullers did not differ significantly from each other on neurocognitive measures. Conclusions. The results suggest common clinical features and associated neural dysfunction between relief and pleasure/gratification pullers, rather than supporting their existence as discrete clinical entities. Selection of appropriate treatment may focus on other aspects of hair pulling, including family history and comorbidity.

Key words::

• Cognition
• comorbidity
• hair-pulling disorder
• impulse control
• trichotillomania

Acknowledgments

None to report.

Statement of interest

This research is supported by a research grant from the Trichotillomania Learning Center to Mr. Odlaug and a Center for Excellence in Gambling Research grant by the Center for Responsible Gaming to Dr. Grant. Disclosures of interest include that Mr. Odlaug has received research grants from the Trichotillomania Learning Center, has consulted for Lundbeck Pharmaceuticals, and has received honoraria and royalties from Oxford University Press. Dr. Chamberlain has consulted for Cambridge Cognition, P1Vital, Shire, and Lilly. Dr. Grant has received research grants from NIDA, and National Center for Responsible Gaming, Transcept, Roche, Forest, and Psyadon Pharmaceuticals, and the University of South Florida. Dr. Grant receives compensation from Springer as the editor-in-chief of the Journal of Gambling Studies and has received royalties from McGraw Hill, Oxford University Press, Norton, and the APPI. Ms. Schreiber reports no conflicts of interest.