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BackgroundA promising approach to reducing the phenotypic heterogeneity of psychiatric disorders involves the identification of homogeneous subtypes. Careful study of comorbidity in obsessive‐compulsive disorder (OCD) contributed to the identification of the DSM‐5 subtype of OCD with tics. Here we investigated one of the largest available cohorts of clinically diagnosed trichotillomania (TTM) to determine whether subtyping TTM based on comorbidity would help delineate clinically meaningful subgroups.MethodsAs part of an ongoing international collaboration, lifetime comorbidity data were collated from 304 adults with pathological hair‐pulling who fulfilled criteria for DSM‐IV‐TR or DSM‐5 TTM. Cluster analysis (Ward's method) based on comorbidities was undertaken.ResultsThree clusters were identified, namely Cluster 1: cases without any comorbidities (n = 63, 20.7%) labeled “simple TTM,” Cluster 2: cases with comorbid major depressive disorder only (N = 49, 16.12%) labeled “depressive TTM,” and Cluster 3: cases presenting with combinations of the investigated comorbidities (N = 192, 63.16%) labeled “complex TTM.” The clusters differed in terms of hair‐pulling severity (F = 3.75, p = .02; Kruskal–Wallis [KW] p < .01) and depression symptom severity (F = 5.07, p = <.01; KW p < .01), with cases with any comorbidity presenting with increased severity. Analysis of the temporal nature of these conditions in a subset suggested that TTM onset generally preceded major depressive disorder in (subsets of) Clusters 2 and 3.ConclusionsThe findings here are useful in emphasizing that while many TTM patients present without comorbidity, depression is present in a substantial proportion of cases. In clinical practice, it is crucial to assess comorbidity, given the links demonstrated here between comorbidity and symptom severity. Additional research is needed to replicate these findings and to determine whether cluster membership based on comorbidity predicts response to treatment.

In the present study, we evaluated the Milwaukee Inventory for Subtypes of TrichotillomaniaAdult Version (MIST-A) in a replication sample of clinically characterized hair pullers using exploratory factor analysis (EFA; N = 193). EFA eigenvalues and visual inspection of our scree plot revealed a two-factor solution. Factor structure coefficients and internal consistencies suggested a 13-item scale with an 8-item "Intention" scale and a 5-item "Emotion" scale. Both scales displayed good construct and discriminant validity. These findings indicate the need for a revised scale that provides a more refined assessment of pulling phenomenology that can facilitate future treatment advances. HHS Public Access Author ManuscriptAuthor Manuscript Author ManuscriptAuthor Manuscript researchers to propose the existence of different hair-pulling subtypes or styles (e.g., Christenson & Mackenzie, 1994;Christenson, Mackenzie, & Mitchell, 1991;du Toit, van Kradenburg, Niehaus, & Stein, 2001). This parsing of the TTM phenomenology subsequently led to the suggestion that different clinical presentations may warrant different treatment strategies (e.g., Franklin, Tolin, & Diefenbach, 2006;. Accordingly, assessment instruments that evaluate the extent of severity of different pulling styles may assist with treatment tailoring and the optimization of clinical care.To date, the most widely endorsed pulling styles are the "automatic" and "focused" types. The "automatic" style involves pulling in the absence of full behavioral awareness and is generally associated with sedentary situations (e.g., reading or watching television). In contrast, the "focused" style involves affect-driven pulling with full behavioral awareness and is often done in response to intense emotions or other uncomfortable internal experiences. It has been suggested that traditional habit reversal treatment may have the greatest benefit for hair pulling that is predominantly "automatic," while interventions addressing experiential avoidance or emotion dysregulation may be warranted to address "focused" pulling (e.g., Flessner, Conelea, et al., 2008).Flessner and colleagues (Flessner et al., 2007; developed reliable and valid self-report scales using data from large-sample Internet studies to assess these hair pulling styles in adult and pediatric populations. The adult version of the scale, the Milwaukee Inventory for Subtypes of Trichotillomania-Adult Version (MIST-A; , was developed using a sample of 1,697 Internet participants who reported pulling their hair frequently but were not assessed via clinical interview. Two factors ("automatic" and "focused") resulted from exploratory factor analysis (EFA) and were subsequently supported with confirmatory factor analysis (CFA). The final scale consisted of "Focused" and "Automatic" scales, with 10 and 5 items, respectively. Both scales had adequate internal consistency and good construct and discriminant validity.The original article on the development of the MIST-A highlighted the importance of replicating th...

A growing literature is utilizing machine learning methods to develop psychopathology risk algorithms that can be used to inform preventive intervention. However, efforts to develop algorithms for internalizing disorder onset have been limited. The goal of this study was to utilize prospective survey data and ensemble machine learning to develop algorithms predicting adult onset internalizing disorders. The data were from Waves 1-2 of the National Epidemiological Survey on Alcohol and Related Conditions (n = 34,653). Outcomes were incident occurrence of DSM-IV generalized anxiety, panic, social phobia, depression, and mania between Waves 1-2. In total, 213 risk factors (features) were operationalized based on their presence/occurrence at the time of or before Wave 1. For each of the five internalizing disorder outcomes, super learning was used to generate a composite algorithm from several linear and non-linear classifiers (e.g., random forests, k-nearest neighbors). AUCs achieved by the cross-validated super learner ensembles were in the range of 0.76 (depression) to 0.83 (mania), and were higher than AUCs achieved by the individual algorithms. Individuals in the top 10% of super learner predicted risk accounted for 37.97% (depression) to 53.39% (social anxiety) of all incident cases. Thus, the algorithms achieved acceptable-to-excellent prediction accuracy with a high concentration of incident cases observed among individuals predicted to be highest risk. In parallel with the development of effective preventive interventions, further validation, expansion, and dissemination of algorithms predicting internalizing disorder onset/trajectory could be of great value.

Trichotillomania/hair pulling disorder (HPD) and excoriation/skin picking disorder (SPD) are childhood-onset, body-focused repetitive behaviors that are thought to share genetic susceptibility and underlying pathophysiology with obsessive-compulsive disorder (OCD) and Tourette syndrome (TS). We sought to determine the prevalence of DSM-5 HPD and SPD in TS patients, and to identify clinical factors most associated with their co-morbidity with TS. Participants included 811 TS patients recruited from TS specialty clinics for a multi-center genetic study. Patients were assessed using standardized, validated semi-structured interviews. HPD and SPD diagnoses were determined using a validated self-report questionnaire. HPD/SPD prevalence rates were calculated, and clinical predictors were evaluated using regression modeling. 3.8 and 13.0% of TS patients met DSM-5 criteria for HPD and SPD, respectively. In univariable analyses, female sex, OCD, and both tic and obsessive-compulsive symptom severity were among those associated with HPD and/or SPD. In multivariable analyses, only lifetime worst-ever motor tic severity remained significantly associated with HPD. Female sex, co-occurring OCD, ADHD, and motor tic severity remained independently associated with SPD. This is the first study to examine HPD and SPD prevalence in a TS sample using semi-structured diagnostic instruments. The prevalence of HPD and SPD in TS patients, and their association with increased tic severity and co-occurring OCD, suggests that clinicians should screen children with TS and related disorders for HPD/SPD, particularly in females and in those with co-occurring OCD. This study also helps set a foundation for subsequent research regarding HPD/SPD risk factors, pathophysiology, and treatment models.

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Trichotillomania (TTM) and eating disorders (ED) share many phenomenological similarities, including ritualized compulsive behaviors. Given this, and that comorbid EDs may represent additional functional burden to hair pullers, we sought to identify factors that predict diagnosis of an ED in a TTM population. Subjects included 555 adult females (age range 18-65) with DSM-IV-TR TTM or chronic hair pullers recruited from multiple sites. 7.2% (N=40) of our TTM subjects met criteria for an ED in their lifetime. In univariable regression analysis, obsessive-compulsive disorder (OCD), Yale-Brown Obsessive Compulsive Scale (Y-BOCS) worst-ever compulsion and total scores, certain obsessive-compulsive spectrum disorders, anxiety disorder, attention-deficit/hyperactivity disorder (ADHD), and substance disorder all met the pre-specified criteria for inclusion in the multivariable analysis. In the final multivariable model, diagnosis of OCD (OR: 5.68, 95% CI: 2.2-15.0) and diagnosis of an additional body-focused repetitive behavior disorder (BFRB) (OR: 2.69, 95% CI: 1.1-6.8) were both associated with increased risk of ED in TTM. Overall, our results provide further support of the relatedness between ED and TTM. This finding highlights the importance of assessing for comorbid OCD and additional BFRBs in those with TTM. Future research is needed to identify additional predictors of comorbid disorders and to better understand the complex relationships between BFRBs, OCD and EDs.

Worry behaviors (i.e., overt acts to avoid or cope with worry-induced distress) have been recognized as being important in the psychopathology and treatment of generalized anxiety disorder (GAD). This study evaluated the worry behaviors criterion proposed for DSM-5 GAD, but was ultimately not adopted due to insufficient evidence. In 800 outpatients with emotional disorders (366 with GAD), most patients with GAD (92.6%) met the proposed worry behaviors criterion, which was at a rate significantly higher than other patient groups (e.g., patients with mood disorders). Patients who met the worry behaviors criterion had more severe GAD than patients who did not. The worry behaviors criterion, and 3 of its 4 constituent behaviors, were associated with no better than “fair” interrater reliability. Diagnostic reliability of GAD was not improved in cases where both interviewers agreed the worry behaviors criterion was met. The worry behaviors criterion significantly predicted DSM-5 GAD holding core GAD features constant (e.g., excessive worry), but this contribution was weak and did not appreciably improve the classification accuracy of GAD diagnostic status. Mixed support was obtained for the discriminant validity of the worry behaviors criterion in relation to mood disorders. Raising the proposed threshold of the criterion (requiring 2 instead of 1 behaviors) did not result in a substantial improvement in reliability, prediction, and classification accuracy. Although additional research is warranted (e.g., importance of worry behaviors in the treatment and natural course of GAD), the results raise questions about the role of worry behaviors in the diagnostic classification of GAD.