Reduced Brain White Matter Integrity in Trichotillomania A Diffusion Tensor Imaging Study

Context: Trichotillomania is an Axis I disorder characterized by repetitive, pathological hair pulling. Objective: To assess the integrity of white matter tracts in subjects with the disorder. Design: Between-group comparison using permutation cluster analysis, with stringent correction for multiple comparisons. Setting: Academic psychiatry department. Participants: Eighteen volunteers meeting DSM-IV criteria for trichotillomania and 19 healthy control subjects. Main Outcome Measures: Fractional anisotropy (measured using diffusion tensor imaging), trichotillomania disease severity (Massachusetts General Hospital Hair-pulling Scale score), and dysphoria (Montgomery-Asberg Depression Rating Scale score). Results: Subjects with trichotillomania exhibited significantly reduced fractional anisotropy in anterior cingulate, presupplementary motor area, and temporal cortices. Fractional anisotropy did not correlate significantly with trichotillomania disease severity or depressive mood scores. Conclusions: These data implicate disorganization of white matter tracts involved in motor habit generation and suppression, along with affective regulation, in the pathophysiology of trichotillomania.