Executive functioning in trichotillomania and skin picking disorder: A review of neurocognitive findings

Abstract

Trichotillomania (TTM; hair pulling disorder) and excoriation disorder (skin picking disorder [SPD]) are obsessive-compulsive spectrum disorders with potential neurobiological underpinnings. Neuroimaging studies implicate frontal-striatal circuitry, suggesting executive functioning deficits. This brief review summarizes existing neuropsychological research on TTM and SPD within three domains of executive functioning: inhibition, shifting, and updating. Current evidence consistently indicates that both TTM and SPD are characterized by impaired response inhibition. Some studies in TTM show deficits in mental shifting abilities, while findings in SPD are mixed. Updating is inconsistently impacted in TTM and remains largely unstudied in SPD. Limitations of existing literature include small sample sizes, methodological variations, and few studies in SPD. Future research should examine executive functioning in TTM and SPD across different contexts and repeated measures to improve reliability and generalizability of findings. Overall, executive functioning in TTM and SPD warrants continued investigation, as it may assist in enhancing our understanding of the cognitive mechanisms underlying these disorders.