Trichotillomania, Skin Picking Disorder, and Different Aspects of Impulsivity: A Systematic Review

Abstract

Trichotillomania and skin picking disorder are psychiatric disorders with body-focused repetitive behaviors (BFRB). Impulsivity is considered to have a role in the etiology of BFRB. Various methods have been implemented to demonstrate different aspects of impulsivity due to its multidimensional construct. This systematic review aimed to synthesize existing studies to examine different aspects of impulsivity in BFRB. A systematic literature review was conducted in January 2021. Some original studies evaluating the relationship between impulsivity and trichotillomania or skin picking disorder were obtained. Twenty studies were examined after a systematic search of the MEDLINE database. The findings revealed that impulsivity was investigated using a self-report scale in five studies and behavioral tasks in 18 studies. Five studies reported higher trait impulsivity in BFRB with different self-report scales. Differences have been found in the urgency, motor, and attentional subscales. Eight studies measuring motor impulsivity (response inhibition) with behavioral tasks showed higher impulsivity in BFRB and its subgroups. Three studies evaluating cognitive impulsivity with behavioral tasks reported that BFRB is not related to reflection and decision-making impulsivity. However, functional alterations in BFRB patients fMRI, during a choice impulsivity task, were shown in one study only. Different aspects of impulsivity are associated with BFRB. The most commonly identified impairment with behavioral tasks, response inhibition impairment, is conceptually similar to the urgency and motor subscales determined by self-report scales. These results support the patients' self-reports and explain the patients' tendency to act rashly under an increasing sense of tension. However, further studies should be conducted to make a definite conclusion about cognitive impulsivity characteristics of BFRB patients. [ Psychiatr Ann . 2022;52(12):527–540.]