The validity of DSM-IV-TR criteria B and C of hair-pulling disorder (trichotillomania): evidence from a clinical study.

In both DSM-IV-TR and the ICD-10, hair-pulling disorder (trichotillomania, or TTM) is described as hair-pulling, with a rising urge or tension prior to pulling or when attempting to resist, and pleasure, relief or gratification during or after pulling. However, it has been questioned whether all patients with hair-pulling experience these other phenomena, and whether they occur with all pulling episodes. The objective of this study was to examine the DSM-IV-TR requirement of criteria B and C for a diagnosis of TTM in a sample of people with hair-pulling. A multi-site sample of adults with hair-pulling who met both DSM-IV-TR diagnostic criteria B and C (n=82, 89.13%) were compared to those who failed to satisfy both B and C (n=10, 10.87%) on a number of clinical variables. There were no differences in hair-pulling severity, levels of comorbid depressive and anxiety symptoms, number of comorbid body-focused repetitive behaviors, or impairment between those patients who did and did not meet criteria B and C. Our study does not provide convincing support for the inclusion of the current diagnostic criteria B and C for TTM in DSM-5.