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$\textit{Background:}$ Trichotillomania appears to be a fairly common disorder, with high rates of co-occurring anxiety disorders. Many individuals with trichotillomania also report that pulling worsens during periods of increased anxiety. Even with these clinical links to anxiety, little research has explored whether trichotillomania with co-occurring anxiety is a meaningful subtype. $\textit{Methods:}$ One hundred sixty-five adults with trichotillomania were examined on a variety of clinical measures including symptom severity, functioning, and comorbidity. Participants also underwent cognitive testing assessing motor inhibition and cognitive flexibility. Clinical features and cognitive functioning were compared between those with current co-occurring anxiety disorders (i.e. social anxiety, generalized anxiety disorder, panic disorder, and anxiety disorder NOS) (n = 38) and those with no anxiety disorder (n = 127). $\textit{Results:}$ Participants with trichotillomania and co-occurring anxiety reported significantly worse hair pulling symptoms, were more likely to have co-occurring depression, and were more likely to have a first-degree relative with obsessive compulsive disorder. Those with anxiety disorders also exhibited significantly worse motor inhibitory performance on a task of motor inhibition (stop-signal task). $\textit{Conclusions:}$ This study suggests that anxiety disorders affect the clinical presentation of hair pulling behavior. Further research is needed to validate our findings and to consider whether treatments should be specially tailored differently for adults with trichotillomania who have co-occurring anxiety disorders, or more pronounced cognitive impairment.

Excoriation (skin-picking) disorder (SPD) shares symptomology with other obsessive-compulsive and related disorders. Few studies, however, have examined the neurological profile of patients with SPD. This study examined differences in cortical thickness and basal ganglia structural volumes between 20 individuals with SPD and 16 healthy controls using magnetic resonance imaging (MRI). There were no significant differences in demographic variables (age, gender, education and race) between groups. All subjects completed a structural MRI scan and completed a battery of clinical assessments focusing on SPD symptom severity, depression and anxiety symptoms, and quality of life. No statistically significant differences in basal ganglia (caudate, putamen, and nucleus accumbens) structural volumes were found between groups. In individuals with SPD, increasing impulsiveness correlated positively with increased cortical thickness in the left insula, and skin picking severity correlated negatively with cortical thickness in the left supramarginal gyrus and a region encompassing the right inferior parietal, right temporal and right supramarginal gyrus. This study suggests similarities and differences exist in symptomology between SPD and the other obsessive-compulsive and related disorders. Additional neuroimaging research is needed to better delineate the underlying neurobiology of SPD.