Prevalence and Correlates of Hair Pulling Disorder and Skin Picking Disorder in an Acute Psychiatric Sample.

ABSTRACT: Hair pulling disorder (HPD; trichotillomania) and skin picking disorder (SPD; excoriation disorder) are understudied psychiatric disorders. The aim of this study was to examine the prevalence and correlates of HPD and SPD in an acute psychiatric sample. Semistructured interviews and self-report measures were administered to patients in a psychiatric partial hospital (N = 599). The past-month prevalence of HPD and SPD was 2.3% and 9%, respectively. HPD and SPD had highly similar clinical characteristics and a strong co-occurrence. Patients with HPD/SPD were significantly younger than other patients and more likely to be female. Logistic regression controlling for age and sex showed that diagnosis of HPD/SPD was not significantly associated with suicidal ideation, suicidal behaviors, nonsuicidal self-injury, or emotional disorder diagnoses (e.g., borderline personality disorder, major depressive disorder). HPD/SPD status was significantly associated with an increased risk of generalized anxiety disorder. However, patients with HPD/SPD did not differ from other patients on self-report measures of generalized anxiety, depression, and distress intolerance. HPD and SPD are common and frequently co-occurring disorders in psychiatric settings.

Neurobiology of subtypes of trichotillomania and skin picking disorder.

BACKGROUND: Trichotillomania (TTM) and skin picking disorder (SPD) are common and often debilitating mental health conditions, grouped under the umbrella term of body-focused repetitive behaviors (BFRBs). Recent clinical subtyping found that there were three distinct subtypes of TTM and two of SPD. Whether these clinical subtypes map on to any unique neurobiological underpinnings, however, remains unknown. METHODS: Two hundred and fifty one adults [193 with a BFRB (85.5% [n = 165] female) and 58 healthy controls (77.6% [n = 45] female)] were recruited from the community for a multicenter between-group comparison using structural neuroimaging. Differences in whole brain structure were compared across the subtypes of BFRBs, controlling for age, sex, scanning site, and intracranial volume. RESULTS: When the subtypes of TTM were compared, low awareness hair pullers demonstrated increased cortical volume in the lateral occipital lobe relative to controls and sensory sensitive pullers. In addition, impulsive/perfectionist hair pullers showed relative decreased volume near the lingual gyrus of the inferior occipital-parietal lobe compared with controls. CONCLUSIONS: These data indicate that the anatomical substrates of particular forms of BFRBs are dissociable, which may have implications for understanding clinical presentations and treatment response.

Clinical Characteristics of Youth with Trichotillomania (Hair-Pulling Disorder) and Excoriation (Skin-Picking) Disorder.

Body-focused repetitive disorders (BFRBDs) are understudied in youth and understanding of their underlying mechanisms is limited. This study evaluated BFRBD clinical characteristics, and two factors commonly implicated in their maintenance - emotion regulation and impulsivity - in 53 youth aged 11 to 17 years: 33 with BFRBDs and 20 controls. Evaluators administered psychiatric diagnostic interviews. Participants rated BFRBD severity, negative affect, quality of life, family functioning, emotion regulation, distress tolerance, and impulsivity. Youth with BFRBDs showed poorer distress tolerance and quality of life, and higher impulsivity and negative affect than controls, with no differences in family impairment. BFRBD distress/impairment, but not BFRBD severity, correlated with anxiety and depression, and poorer distress tolerance. Findings suggest youth with BFRBDs show clinical patterns aligning with prior research; highlight the role of distress tolerance in child BFRBDs; and suggest the utility of acceptance and mindfulness-based therapies for unpleasant emotions in BFRBDs. Continued research should evaluate factors underlying BFRBDs in youth.

Pain perception and physiological correlates in body-focused repetitive behavior disorders.

BACKGROUND: Behaviors typical of body-focused repetitive behavior disorders such as trichotillomania (TTM) and skin-picking disorder (SPD) are often associated with pleasure or relief, and with little or no physical pain, suggesting aberrant pain perception. Conclusive evidence about pain perception and correlates in these conditions is, however, lacking. METHODS: A multisite international study examined pain perception and its physiological correlates in adults with TTM (n = 31), SPD (n = 24), and healthy controls (HCs; n = 26). The cold pressor test was administered, and measurements of pain perception and cardiovascular parameters were taken every 15 seconds. Pain perception, latency to pain tolerance, cardiovascular parameters and associations with illness severity, and comorbid depression, as well as interaction effects (group × time interval), were investigated across groups. RESULTS: There were no group differences in pain ratings over time (P = .8) or latency to pain tolerance (P = .8). Illness severity was not associated with pain ratings (all P > .05). In terms of diastolic blood pressure (DBP), the main effect of group was statistically significant (P = .01), with post hoc analyses indicating higher mean DBP in TTM (95% confidence intervals [CI], 84.0-93.5) compared to SPD (95% CI, 73.5-84.2; P = .01), and HCs (95% CI, 75.6-86.0; P = .03). Pain perception did not differ between those with and those without depression (TTM: P = .2, SPD: P = .4). CONCLUSION: The study findings were mostly negative suggesting that general pain perception aberration is not involved in TTM and SPD. Other underlying drivers of hair-pulling and skin-picking behavior (eg, abnormal reward processing) should be investigated.

Reward processing in trichotillomania and skin picking disorder.

Trichotillomania (hair pulling disorder) and skin picking disorder are common and often debilitating mental health conditions, grouped under the umbrella term of body focused repetitive behaviors (BFRBs). Although the pathophysiology of BFRBs is incompletely understood, reward processing dysfunction has been implicated in the etiology and sustention of these disorders. The purpose of this study was to probe reward processing in BFRBs. 159 adults (125 with a BFRB [83.2% (n = 104) female] and 34 healthy controls [73.5% (n = 25) female]) were recruited from the community for a multi-center between-group comparison using a functional imaging (fMRI) monetary reward task. Differences in brain activation during reward anticipation and punishment anticipation were compared between BFRB patients and controls, with stringent correction for multiple comparisons. All group level analyses controlled for age, sex and scanning site. Compared to controls, BFRB participants showed marked hyperactivation of the bilateral inferior frontal gyrus (pars opercularis and pars triangularis) compared to controls. In addition, BFRB participants exhibited increased activation in multiple areas during the anticipation of loss (right fusiform gyrus, parahippocampal gyrus, cerebellum, right inferior parietal lobule; left inferior frontal gyrus). There were no significant differences in the win-lose contrast between the two groups. These data indicate the existence of dysregulated reward circuitry in BFRBs. The identified pathophysiology of reward dysfunction may be useful to tailor future treatments.

Identifying subtypes of trichotillomania (hair pulling disorder) and excoriation (skin picking) disorder using mixture modeling in a multicenter sample.

Body-focused repetitive behavior disorders (BFRBs) include Trichotillomania (TTM; Hair pulling disorder) and Excoriation (Skin Picking) Disorder (SPD). These conditions are prevalent, highly heterogeneous, under-researched, and under-treated. In order for progress to be made in optimally classifying and treating these conditions, it is necessary to identify meaningful subtypes. 279 adults (100 with TTM, 81 with SPD, 40 with both TTM and SPD, and 58 controls) were recruited for an international, multi-center between-group comparison using mixture modeling, with stringent correction for multiple comparisons. The main outcome measure was to examine distinct subtypes (aka latent classes) across all study participants using item-level data from gold-standard instruments assessing detailed clinical measures. Mixture models identified 3 subtypes of TTM (entropy 0.98) and 2 subtypes of SPD (entropy 0.99) independent of the control group. Significant differences between these classes were identified on measures of disability, automatic and focused symptoms, perfectionism, trait impulsiveness, and inattention and hyperactivity. These data indicate the existence of three separate subtypes of TTM, and two separate subtypes of SPD, which are distinct from controls. The identified clinical differences between these latent classes may be useful to tailor future treatments by focusing on particular traits. Future work should examine whether these latent subtypes relate to treatment outcomes, or particular psychobiological findings using neuroimaging techniques.

Duration of illness and cortical thickness in trichotillomania: Preliminary evidence for illness change over time.

Trichotillomania is a psychiatric condition characterized by repetitive pulling out of one's hair, leading to marked functional impairment. The aim of this study was to examine the association between duration of trichotillomania (defined as time between initial age of onset and current age) and structural brain abnormalities by pooling all available global data. Authors of published neuroimaging studies of trichotillomania were contacted and invited to contribute de-identified MRI scans for a pooled analysis. Freesurfer pipelines were used to examine whether cortical thickness and sub-cortical volumes were associated with duration of illness in adults with trichotillomania. The sample comprised 50 adults with trichotillomania (100% not taking psychotropic medication; mean [SD] age 34.3 [12.3] years; 92% female). Longer duration of illness was associated with lower cortical thickness in bilateral superior frontal cortex and left rostral middle frontal cortex. Volumes of the a priori sub-cortical structures of interest were not significantly correlated with duration of illness (all p > 0.05 uncorrected). This study is the first to suggest that trichotillomania is associated with biological changes over time. If this finding is supported by prospective studies, it could have important implications for treatment (i.e. treatment might need to be tailored for stage of illness). Viewed alongside prior work, the data suggest that brain changes in trichotillomania may be differentially associated with vulnerability (excess thickness in right inferior frontal cortex) and with chronicity (reduced thickness in medial and superior frontal cortex). Longitudinal research is now indicated.

Comorbidity in trichotillomania (hair-pulling disorder): A cluster analytical approach.

BACKGROUND: A 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. METHODS: As 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. RESULTS: Three 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. CONCLUSIONS: The 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.

A latent profile analysis of age of onset in trichotillomania.

BACKGROUND: Trichotillomania (TTM) onset may occur across the lifespan; however, adolescent onset is most frequently reported. Several studies have explored clinical differences between TTM age-of-onset groups with mixed results. We investigated empirically defined age-of-onset groups in adults with TTM, and clinical differences between groups. METHODS: Participants included 1,604 adult respondents to an internet survey who endorsed DSM-IV-TR TTM criteria. Latent profile analysis was performed to identify TTM age-of-onset subgroups, which were then compared on demographic and clinical features. RESULTS: The most optimal model was a 2-class solution comprised of a large group with average TTM onset during adolescence (n = 1,539; 95.9% of the sample; mean age of onset = 12.4) and a small group with average onset in middle adulthood (n = 65; 4.1% of the sample; mean age of onset = 35.6). The late-onset group differed from the early-onset group on several clinical variables (eg, less likely to report co-occurring bodyfocused repetitive behaviors). CONCLUSIONS: Findings suggest the presence of at least 2 distinct TTM age-of-onset subgroups: an early-onset group with onset during adolescence, and a late-onset group with onset in middle adulthood. Future research is needed to further validate these subgroups and explore their clinical utility.

Striatal abnormalities in trichotillomania: a multi-site MRI analysis.

Trichotillomania (hair-pulling disorder) is characterized by the repetitive pulling out of one's own hair, and is classified as an Obsessive-Compulsive Related Disorder. Abnormalities of the ventral and dorsal striatum have been implicated in disease models of trichotillomania, based on translational research, but direct evidence is lacking. The aim of this study was to elucidate subcortical morphometric abnormalities, including localized curvature changes, in trichotillomania. De-identified MRI scans were pooled by contacting authors of previous peer-reviewed studies that examined brain structure in adult patients with trichotillomania, following an extensive literature search. Group differences on subcortical volumes of interest were explored (t-tests) and localized differences in subcortical structure morphology were quantified using permutation testing. The pooled sample comprised N=68 individuals with trichotillomania and N=41 healthy controls. Groups were well-matched in terms of age, gender, and educational levels. Significant volumetric reductions were found in trichotillomania patients versus controls in right amygdala and left putamen. Localized shape deformities were found in bilateral nucleus accumbens, bilateral amygdala, right caudate and right putamen. Structural abnormalities of subcortical regions involved in affect regulation, inhibitory control, and habit generation, play a key role in the pathophysiology of trichotillomania. Trichotillomania may constitute a useful model through which to better understand other compulsive symptoms. These findings may account for why certain medications appear effective for trichotillomania, namely those modulating subcortical dopamine and glutamatergic function. Future work should study the state versus trait nature of these changes, and the impact of treatment.

Cortical thickness abnormalities in trichotillomania: international multi-site analysis.

Trichotillomania is a prevalent but often hidden psychiatric condition, characterized by repetitive hair pulling. The aim of this study was to confirm or refute structural brain abnormalities in trichotillomania by pooling all available global data. De-identified MRI scans were pooled by contacting authors of previous studies. Cortical thickness and sub-cortical volumes were compared between patients and controls. Patients (n = 76) and controls (n = 41) were well-matched in terms of demographic characteristics. Trichotillomania patients showed excess cortical thickness in a cluster maximal at right inferior frontal gyrus, unrelated to symptom severity. No significant sub-cortical volume differences were detected in the regions of interest. Morphometric changes in the right inferior frontal gyrus appear to play a central role in the pathophysiology of trichotillomania, and to be trait in nature. The findings are distinct from other impulsive-compulsive disorders (OCD, ADHD, gambling disorder), which have typically been associated with reduced, rather than increased, cortical thickness. Future work should examine sub-cortical and cerebellar morphology using analytic approaches designed for this purpose, and should also characterize grey matter densities/volumes.

Prevalence and predictors of hair pulling disorder and excoriation disorder in Tourette syndrome.

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.

Predictors of comorbid eating disorders and association with other obsessive-compulsive spectrum disorders in trichotillomania.

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.

Placebo response in trichotillomania.

Trichotillomania is a functionally impairing, often overlooked disorder with no Food and Drug Administration-approved medications indicated for its treatment. The ability of clinical trials to detect the beneficial effects of pharmacologic treatment in trichotillomania has been hampered by the high placebo response rate. Very little is known about baseline demographic and clinical characteristics that may be predictive of placebo response in such patients. Overall, 104 participants assigned to placebo were pooled from five double-blind trials conducted at three sites in the USA and Canada. Participants were classified as placebo responders or nonresponders on the basis of a cutoff of a 35% reduction in symptom severity on the Massachusetts General Hospital Hair Pulling Scale. Baseline group differences were characterized using t-tests and equivalent nonparametric tests as appropriate. Thirty-one percent of individuals assigned to placebo treatment showed a significant clinical response to placebo. Placebo responders (n=32) and nonresponders (n=72) did not differ significantly on any demographic or clinical variable. Predictors of placebo response for trichotillomania remain elusive and do not appear to be similar to those reported for other mental health disorders.

Trichotillomania and its clinical relationship to depression and anxiety.

OBJECTIVE: Trichotillomania (TTM) is associated with high rates of co-occurring depression and anxiety disorders. What the co-occurrence of TTM, depression or anxiety disorders means clinically and cognitively, however, has garnered little research attention. METHODS: About 530 adults with TTM were examined on a variety of clinical measures including symptom severity, psychosocial measures of functioning, psychiatric comorbidity and neurocognitive testing assessing motor inhibition and cognitive flexibility. Clinical features and cognitive functioning were compared between TTM patients with current comorbid major depressive disorder (MDD), a current anxiety disorder, both MDD and an anxiety disorder, or neither. RESULTS: Of 530 participants, 58 (10.3%) had MDD only, 97 (18.3%) had an anxiety disorder only, 58 (10.3%) had both MDD and an anxiety disorder, and 317 (59.8%) had neither. For almost all clinical measures, those with MDD only reported worse symptoms than those with an anxiety disorder only, and the combination of MDD and an anxiety disorder reported the worst level of symptom severity. CONCLUSIONS: These results suggest that adults with TTM and co-occurring MDD and anxiety disorders exhibit unique clinical differences. The clinical differences may also have treatment implications.

The assessment of skin picking in adolescence: psychometric properties of the Skin Picking Scale-Revised (German version).

BACKGROUND: Skin picking disorder has received growing attention since the release of DSM-5, yet there are no evidence-based assessment instruments for adolescent samples. AIM: The present study examines the psychometric properties of the Skin Picking Scale-Revised (SPS-R, German version) in adolescents. METHODS: A total of 76 adolescents (96% female) completed the SPS-R, the Clinical Psychological Diagnostic System (KPD-38), and a questionnaire assessing demographics and clinical characteristics online. RESULTS: The SPS-R had high internal consistency (α = 0.89) and significant small-to-medium correlations with reduced competence skills, psychological impairment, general life satisfaction, social support, and social problems on the KPD-38. Similar to prior findings for adults, an exploratory factor analysis suggested a two-factor model for the SPS-R in adolescents. Group comparisons failed to show significant differences on SPS-R scores between participants with and without dermatological conditions. CONCLUSIONS: The current results suggest that the SPS-R can be useful in adolescent samples as a reliable and valid instrument for the assessment of skin picking severity. Future research investigating scale validity and factor structure in a clinical sample of adolescent skin pickers is warranted.

Predictors of comorbid obsessive-compulsive disorder and skin-picking disorder in trichotillomania.

BACKGROUND: Trichotillomania (TTM), obsessive-compulsive disorder (OCD), and skin-picking disorder (SPD) frequently occur together and share overlapping phenomenology, pathophysiology, and possible genetic underpinnings. This study sought to identify factors that predict OCD and SPD in hair pullers. METHODS: Five hundred fifty-five adult female hair pullers were recruited from specialty clinics and assessed using standardized, semi-structured interviews and self-reports. Clinical predictors and multivariate models were evaluated using logistic regression modeling. RESULTS: Hair pullers met criteria for OCD (18.9%), SPD (19.5%), or chronic skin picking (CSP) (5%), or both comorbid diagnoses, respectively. In the final multivariate model for OCD, family history of OCD and an eating disorder diagnosis were associated with an increased risk of OCD in TTM. A nail-biting diagnosis was associated with a decreased risk of OCD in TTM. In the final multivariate model for SPD/CSP, only family history of OCD was associated with an increased risk of SPD/CSP in TTM. CONCLUSIONS: Identification of factors predicting OCD and SPD in TTM provides evidence for the relatedness of these disorders and supports their collective classification as obsessive-compulsive and related disorders (OCRDs) in DSM-5. The findings of this study further underscore the importance of assessing for comorbid OCRDs and family histories of OCRDs in clinical practice.

Does comorbidity matter in body-focused repetitive behavior disorders?

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. 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. 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. 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.

A comparison of clinical vs subclinical skin pickers in Israel.

BACKGROUND: Skin-picking disorder (SPD) was recognized as its own entity for the first time in DSM-5. The existing SPD literature is limited and, to date, no study has examined the differences between clinical and sub- clinical SPD. Identifying differences between these 2 groups may improve diagnostic accuracy, treatment, and prevention efforts. METHODS: Israeli adults (N = 4,325) from 2 previous studies were examined for the presence of clinical and subclinical SPD. Individuals with clinical SPD (n = 150) vs subclinical SPD (n = 219) were compared on skin-picking characteristics, psychological phenomena, and clinical correlates. RESULTS: There were many similarities between clinical and subclinical skin pickers. Individuals with clinical SPD, however, had more severe skin picking, greater associated functional impairment, greater perceived stress, and greater depressive and obsessive-compulsive symptoms, and were also more likely to have a first-degree relative with SPD. CONCLUSIONS: This study suggests that although there are some similarities between clinical and subclinical SPD, there also are distinct differences in the clinical presentation. Understanding these differences may be an important factor in treatment and prevention planning.

Sex differences in trichotillomania.

BACKGROUND: Trichotillomania (TTM) appears to be a fairly common disorder, yet little is known about sex differences in its clinical presentation. Long thought to be a primarily female disorder, males with TTM may have unique clinical presentations. METHODS: Participants with TTM (N = 462) were examined on a variety of clinical measures including symptom severity, functioning, and psychiatric comorbidity. Clinical features were compared between males (n = 27) and females (n = 435). RESULTS: There were many similarities in the clinical presentations of males and females with TTM. Males with TTM, however, were more likely to pull from their face, arms, and torso, and were more likely to suffer from a co-occurring substance use disorder. Females were more likely to be younger and less likely to be married. CONCLUSIONS: This study suggests that, although few males seek treatment for TTM, sex differences may be an important clinical factor when assessing and treating this disorder. Further research is needed to validate these findings and identify whether treatments should be tailored differently for males and females with TTM.