Sensory over-responsivity in trichotillomania (hair-pulling disorder).

Objective: This study was an initial investigation of sensory-over responsivity (SOR) to external sensations among individuals with trichotillomania (TTM).

Methods: Adults endorsing DSM-5 TTM criteria (N = 609) and a non-affected comparison sample (N = 268) completed a self-report survey.

Results: The majority of the TTM group endorsed SOR symptoms; three-quarters endorsed at least mild tactile and auditory SOR. About 15% endorsed SOR symptoms in the severe to extreme range. TTM participants had significantly higher mean scores in both auditory (t (652.89) = -6.51, p < .001, d = .45) and tactile (t (655.24) = -8.38, p < .001, d = .58) modalities than comparison participants, with medium effect sizes. Greater levels of SOR were related to greater levels of perfectionism and by-proxy pulling urges. SOR was significantly and positively correlated with functional impairment when controlling for TTM severity.

Conclusion: This study expands prior work in obsessive-compulsive related disorders by contributing the first data about associations between TTM and over-responsivity to external sensations. Findings collectively suggest SOR may be related to maladaptive emotion regulation processes in TTM. A novel measure of SOR was developed and administered in this study.