How Similar Are the Disorders Included Under the Umbrella of Obsessive-Compulsive Disorder and Related Disorders?-Reply

Wellcome Trus

Impact of obsessive-compulsive personality disorder (OCPD) symptoms in Internet users

Background: Internet use is pervasive in many cultures. Little is known about the impact of Obsessive-Compulsive Personality Disorder (OCPD) symptoms on impulsive and compulsive psychopathologies in people who use the Internet. Method: 1323 adult Internet users completed an online questionnaire quantifying OCPD symptoms, likely occurrence of select mental disorders (OCD, ADHD, problematic Internet use, anxiety), and personality questionnaires of impulsivity (Barratt) and compulsivity (Padua). Predictors of presence of OCPD symptoms (endorsement of at least 4 of 8 DSM criteria) were identified using binary logistic regression. Results: In regression (p<0.001, AUC 0.77), OCPD symptoms were significantly associated with (in order of decreasing effect size): lower non-planning impulsivity, higher ADHD symptoms, problematic Internet use, avoidant personality disorder, female gender, generalized anxiety disorder, and some types of compulsions (checking, dressing/washing). Conclusions: These data suggest that OCPD symptoms, defined in terms of at least 4 of 8 DSM tick-list criteria being met, are common in Internet users. OCPD symptoms were associated with considerably higher levels of psychopathology relating to both impulsive (ADHD) and compulsive (OC-related and problematic Internet use) disorders. These data merit replication and extension using gold-standard in-person clinical assessments, as the current study relied on self-report over the Internet.This research was supported by a Grant from the Academy of Medical Sciences (UK) and by a Wellcome Trust Clinical Fellowship (110049/Z/15/Z)

Trichotillomania and co-occurring anxiety

$\textit{Background:}$ 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

Does comorbidity matter in body-focused repetitive behavior disorders?

$\textbf{BACKGROUND:}$ Trichotillomania (TTM) and skin-picking disorder (SPD) have been characterized as body-focused repetitive behavior disorders (BFRBs). Because BFRBs frequently co-occur, we sought to discover the similarities and differences for individuals having both TTM and SPD as opposed to 1 of these disorders. $\textbf{METHODS:}$ Participants with primary TTM (N = 421) were evaluated regarding the comorbidity of SPD, and participants with primary SPD (N = 124) were evaluated regarding the comorbidity of TTM. The effects of comorbidity overlap on demographic and clinical measures were evaluated. $\textbf{RESULTS:}$ Of the 421 participants with primary TTM, 61 (14.5%) had co-occurring SPD. Of 124 participants with primary SPD, 21 (16.9%) had comorbid TTM. Participants with primary TTM and comorbid SPD had significantly more severe trichotillomania symptoms and were more likely to have major depressive disorder than those with TTM alone. Participants with primary SPD and comorbid TTM reported significantly more severe skin-picking symptoms than those who had only SPD. $\textbf{CONCLUSIONS:}$ Individuals with co-occurring TTM and SPD may have more problematic symptoms with the primary repetitive behavior. Hair pullers with comorbid SPD were more likely to have comorbid depression. Evaluating patients for multiple BFRBs may be important to assess the severity of symptoms and may have treatment implications.This study was funded by the Trichotillomania Learning Center and its BFRB Precision Medicine Initiative