The Milwaukee Inventory for Styles of Trichotillomania-Child Version (MIST-C): initial development and psychometric properties.

This article describes the development and initial psychometric properties of the Milwaukee Inventory for Styles of Trichotillomania-Child Version (MIST-C), a self-report scale designed to assess styles of hair pulling in children and adolescents diagnosed with trichotillomania (TTM). Using Internet sampling procedures, the authors recruited 164 parent-child dyads, the children of whom met modified diagnostic criteria for TTM. The MIST-C was administered in the context of a larger survey examining functional impairment experienced by children with TTM. Results of an exploratory factor analysis on MIST-C items revealed a two-factor solution. Factors 1 ("focused" pulling scale) and 2 ("automatic" pulling scale) consisted of 21 and 4 items, respectively, with both scales demonstrating acceptable internal consistency and good construct and discriminant validity. The development of the MIST-C provides researchers with a reliable and valid assessment of "automatic" and "focused" pulling, and provides a means by which to examine the developmental trajectory and treatment implications of these pulling styles.