Decreased response monitoring in individuals with symptoms of trichotillomania.

Trichotillomania (TTM) was long classified as an impulse-control disorder; however, the many characteristics it shares with obsessive-compulsive disorder (OCD) led to its recategorization in the DSM-V. The present study aimed to assess and inform the taxonomic placement of TTM through an examination of its neural correlates. While research has consistently associated OCD with enhanced response monitoring, the present study investigated whether a similar neural process is associated with TTM. Undergraduates reporting TTM symptoms and controls performed a modified version of the flanker task, and their event-related potentials were examined for between-group differences in error-related negativity (ERN). Results confirm that individuals who have symptoms of hair pulling have significantly smaller ERNs than the control group. Smaller ERNs reflect decreased levels of response monitoring and support the idea that TTM is distinct from OCD.