Emotion regulation and trichotillomania: a comparison of clinical and nonclinical hair pulling.

This study investigated the emotion regulation hypothesis of trichotillomania (TTM) using a retrospective self-report measure and an experimental hair-pulling task. Participants diagnosed with TTM (n=34) and nonclinical control (NC) volunteers (n=32) were compared on ratings of emotional experiences associated with hair pulling. Data from the retrospective self-report measure supported the emotion regulation hypothesis of TTM. The TTM group reported larger decreases than the NC participants in boredom, sadness, anger, and tension, and larger increases in relief and calm from before to during pulling. The TTM group also reported significantly higher ratings of pleasure while pulling. When exploring changes in emotions from during to after pulling, the TTM group reported larger increases than the NC participants in guilt, sadness, and anger; and larger decreases in boredom; while the NC group reported larger increases than the TTM group in happiness, calm, and relief. On the experimental hair-pulling task, the TTM group reported larger decreases in anxiety from before to after pulling, but this effect was only found for a nontypical hair-pulling site. Methodological limitations may account for the lack of group differences on the experimental hair-pulling task.