The genetics of trichotillomania and excoriation disorder: A systematic review.

BACKGROUND: Trichotillomania (TTM) and excoriation disorder (ED) are impairing obsessive-compulsive related disorders that are common in the general population and for which there are no clear first-line medications, highlighting the need to better understand the underlying biology of these disorders to inform treatments. Given the importance of genetics in obsessive-compulsive disorder (OCD), evaluating genetic factors underlying TTM and ED may advance knowledge about the pathophysiology of these body-focused repetitive behaviors. AIM: In this systematic review, we summarize the available evidence on the genetics of TTM and ED and highlight gaps in the field warranting further research. METHOD: We systematically searched Embase, PsycInfo, PubMed, Medline, Scopus, and Web of Science for original studies in genetic epidemiology (family or twin studies) and molecular genetics (candidate gene and genome-wide) published up to June 2023. RESULTS: Of the 3536 records identified, 109 studies were included in this review. These studies indicated that genetic factors play an important role in the development of TTM and ED, some of which may be shared across the OCD spectrum, but there are no known high-confidence specific genetic risk factors for either TTM or ED. CONCLUSIONS: Our review underscores the need for additional genome-wide research conducted on the genetics of TTM and ED, for instance, genome-wide association and whole-genome/whole-exome DNA sequencing studies. Recent advances in genomics have led to the discovery of risk genes in several psychiatric disorders, including related conditions such as OCD, but to date, TTM and ED have remained understudied.

Cognition in trichotillomania: a meta-analysis.

OBJECTIVE: Trichotillomania (TTM) is a mental health disorder characterized by repetitive urges to pull out one's hair. Cognitive deficits have been reported in people with TTM compared to controls; however, the current literature is sparse and inconclusive about affected domains. We aimed to synthesize research on cognitive functioning in TTM and investigate which cognitive domains are impaired. METHODS: After preregistration on the International Prospective Register of Systematic Reviews (PROSPERO), we conducted a comprehensive literature search for papers examining cognition in people with TTM versus controls using validated tests. A total of 793 papers were screened using preestablished inclusion/exclusion criteria, yielding 15 eligible studies. Random-effects meta-analysis was conducted for 12 cognitive domains. RESULTS: Meta-analysis demonstrated significant deficits in motor inhibition and extradimensional (ED) shifting in people with TTM versus controls as measured by the stop-signal task (SST) (Hedge's g = 0.45, [CI: 0.14, 0.75], p = .004) and ED set-shift task (g = 0.38, [CI: 0.13, 0.62], p = .003), respectively. There were no significant between-group differences in the other cognitive domains tested: verbal learning, intradimensional (ID) shifting, road map spatial ability, pattern recognition, nonverbal memory, executive planning, spatial span length, Stroop inhibition, Wisconsin card sorting, and visuospatial functioning. Findings were not significantly moderated by study quality scores. CONCLUSIONS: Motor inhibition and ED set-shifting appear impaired in TTM. However, a cautious interpretation of results is necessary as samples were relatively small and frequently included comorbidities. Treatment interventions seeking to improve inhibitory control and cognitive flexibility merit exploration for TTM.

Topiramate use in a pediatric patient with comorbid bipolar disorder and trichotillomania: A 3-year follow-up.

Trichotillomania (TTM) is an intractable and chronic mental disorder that causes significant distress or functional impairments in various life domains. Most individuals with trichotillomania have other comorbid diagnoses. Bipolar disorder (BD) is one of the most common comorbid conditions. Up to date, no FDA-approved drugs for TTM are available, not to mention children and adolescent patients with TTM and BD. Here, we present a case of an 8-year-old child with a long history of episodic TTM and bipolar disorder who was effectively treated with topiramate in a 3-year follow-up.

Disorders of impulsivity in trichotillomania and skin picking disorder.

Trichotillomania and skin picking disorder are often classified as body-focused repetitive behaviors (BFRBs) as they are characterized by repetitive hair-pulling and skin picking, respectively. They were initially considered to be impulse control disorders despite little research scrutiny. The objective of this study was to examine the relationship of these two conditions to other disorders with impulsive features. Adults with trichotillomania (n = 104) and skin picking (n = 178) or both (n = 96) were recruited from the general community using advertisements and online support groups and completed an online survey. Participants undertook a structured clinical interview and completion of self-report instruments to characterize clinical profiles and associated characteristics. In addition, each participant completed the Minnesota Impulse Disorders Interview to screen for disorders with impulsive features. Of the 378 adults with BFRBs, 134 (35.4%) screened positive for at least one disorder with features of impulsivity with the most common being compulsive buying (18.3%) and problematic use of the internet (17.5%). Participants with a co-occurring disorder of impulsivity reported significantly worse pulling and picking symptoms (p < .001), were more likely to have co-occurring alcohol problems (p < .001) and PTSD (p < .001), and scored higher regarding dissociative symptoms (p < .001). BFRBs are associated with a range of impulsive disorders and the comorbidity may have important treatment implications.

Trichotillomania in sexual minority individuals.

BACKGROUND: Trichotillomania is a common psychiatric disorder, but little is known about whether or how it differs in people with minority sexual identities. We sought to understand whether lesbian, gay, bisexual, and other individuals differ from heterosexual individuals in terms of hair pulling and associated characteristics. METHODS: A total of 207 participants age 18 to 64 with trichotillomania undertook clinical evaluations. Those who identified as sexual minorities were compared to those who identified as heterosexuals on clinical measures, comorbidities, impulsivity, and stress responses. RESULTS: Overall, 33 participants (15.9%) identified as sexual minorities. These individuals showed significantly higher levels of attentional impulsivity and higher rates of co-occurring obsessive-compulsive disorder compared to heterosexual participants. The groups did not differ in terms of trichotillomania severity or dysfunction due to trichotillomania or in terms of stress response CONCLUSIONS: The rate of sexual minorities in this study (15.9%) is higher than recent US Census Bureau data for sexual minorities in the US population (11.7%). People with trichotillomania from sexual minority groups may present with unique clinical symptoms. Treatments may need to be tailored for this population.

Clinical characteristics of trichotillomania.

BACKGROUND: Trichotillomania is a common psychiatric disorder classified as an obsessive-compulsive and related condition in DSM-5. Despite being first described in the 1800s, little is known about its phenomenology and clinical presentation. Most information about trichotillomania is based on small samples. METHODS: Clinical and demographic data were collected from 858 individuals with trichotillomania who participated in research studies that used in-person assessments with validated instruments. RESULTS: A total of 858 adolescents and adults (mean age 29.3; range 11 to 65; 89.9% female) were recruited. The peak age of symptom onset was 11 to 15, and most affected individuals (93.5%) had symptom onset before age 20. Individuals reported pulling from several body sites, and the most frequent triggers were stress and the feel of their hair. Comorbidities included major depressive disorder, generalized anxiety disorder, and skin picking disorder. Most individuals with trichotillomania (61.7%) previously had received treatment. Among those who had received treatment, more individuals had received medication (43.4%) than psychotherapy (33.0%). CONCLUSIONS: This study sheds new light on the clinical presentation and phenomenology of trichotillomania. Results highlight the need for further research into its clinical presentation, longitudinal course, and optimal treatment approaches.

Same but different? Phenomenological differences among various types of body-focused repetitive behaviors.

BACKGROUND: Body-focused repetitive behaviors (BFRBs) are highly prevalent conditions at the border of psychiatry and dermatology. Using a newly developed scale, the Generic BFRB scale (GBS-36), we aimed to compare 4 prominent BFRBs in terms of phenomenology, age at onset, and other illness-related aspects. METHODS: A sample of 391 individuals with different forms of BFRBs completed the GBS-36, the Patient Health Questionnaire-9 (depression), and the World Health Organization Quality of Life-BREF global item (quality of life). RESULTS: Most individuals showed multiple BFRBs (73.9%). Skin picking and nail biting were reported most frequently (nail biting: 68.3%; skin picking: 60.9%; trichotillomania: 52.4%; lip-cheek biting: 31.7%). Nail biting was most common in childhood; the other BFRBs began mainly in adolescence. Both trichotillomania and skin picking were associated with the greatest impairment and urge to perform the behavior. The 2 conditions also showed a higher association with obsessive-compulsive disorder. Overall symptom severity was correlated with earlier age of onset, number of concurrent BFRBs, and severity of depression as well as suicidality. CONCLUSIONS: BFRBs are a heterogeneous group of conditions, with trichotillomania and skin picking showing the largest similarities. Whether the observed differences reflect specific etiological factors awaits further testing.

Hazardous Alcohol Use in Trichotillomania.

Trichotillomania is a prevalent mental health condition characterized by repetitive hair-pulling. Its relationship to alcohol use problems has received virtually no research scrutiny. Adults with trichotillomania (n = 121) were recruited from the general community, along with 66 healthy controls for reference purposes (in terms of overall levels of hazardous drinking). Participants undertook structured clinical interview and completion of self-report instruments to characterize clinical profiles and associated characteristics. In the trichotillomania sample, we compared variables of interest between those with past-year hazardous alcohol use and those without. Of the 121 adults with trichotillomania, 16 (13.2%) scored ≥ 8 on the AUDIT indicating hazardous alcohol use as compared to 5 (7.5%) of the healthy controls - this difference was not statistically significant. In trichotillomania cases, past year hazardous drinking was associated with significantly higher trait impulsivity, but not with differences in the other variables that were examined. This study highlights the importance of screening for alcohol use problems in people with trichotillomania. More research is needed into this comorbid presentation, including work to explore the impact of hazardous alcohol use on clinical treatment outcomes, as well as how treatments might best be adapted to treat individuals affected by both disorders.

Suicidal ideation and attempts in trichotillomania.

Trichotillomania is characterized by chronic pulling out of one's hair. Given the negative sequelae of trichotillomania, we examined rates of suicidal ideation and suicide attempts. Of the 219 adults (mean age = 29.5 years; 88% female) recruited, 40 (18.3%) reported lifetime suicidal ideation, and 5 (2.3%) reported a lifetime suicide attempt. Those with histories of suicidal ideation were significantly more likely to have major depressive disorder. Our findings suggest that suicidal ideation and attempts are common in trichotillomania and support the idea that comorbid depression should be considered a risk factor for suicidality.

Body Focused Repetitive Behavior Disorders: Behavioral Models and Neurobiological Mechanisms. / Beden Odakli Tekrarlayici Davranis Bozukluklari: Davranis Modelleri ve Nörobiyolojik Mekanizmalar.

OBJECTIVE: Body Focused Repetitive Behaviors (BFRB) is an umbrella term for undesirable, repetitive motor activities such as Trichotillomania (TTM), Skin Picking Disorder (SPD), nail biting, cheek chewing, lip biting, finger sucking, finger cracking and teeth grinding. Such behaviors are engaged in to eliminate a part of the body and may result in impaired functionality. The frequency of presentation to clinicians is low since BFRB are defined as harmless, although the number of studies on this condition has increased rapidly recently, including those making a clear determination of epidemiological data, those investigating the etiopathogenesis and those providing treatment guidelines, although they remain inadequate. The present study provides a review of studies investigating the etiology of BFRB to date. METHOD: Articles published between 1992 and 2021 stored in the Pubmed, Medline, Scopus and Web of Science databases were reviewed, and the prominent research studies of the condition identified were included in the evaluation. RESULTS: Studies investigating the etiopathogenesis of BFRB were found in most cases to investigate adult populations, and were hampered by such confounding factors as clinical heterogeneity, high rates of comorbid psychiatric diseases and small sample sizes. The identified studies reveal that attempts have been made to explain BFRB based on behavioral models, and that the condition is inherited at a high rate. Treatment planning is mostly associated with monoamine systems (especially glutamate and dopamine) and interventions were directed to addiction elements. Furthermore, cognitive flexibility and motor inhibition defects in neurocognitive area and cortico-striato-thalamocortical cycle abnormalities in neuroimaging studies have been reported. CONCLUSION: Studies investigating the clinical features, incidence, etiopathogenesis and treatment of BFRB, which holds a controversial place in psychiatric classification systems, would contribute to a better understanding of the disease and a more appropriate definition of the condition.

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.

Sociodemographic variables, clinical characteristics, and treatments in children with trichotillomania in terms of age and gender: a multicenter study.

OBJECTIVE: Although trichotillomania (TTM) is a common, typically pediatric-onset disorder, data on the phenomenology of TTM in children, accompanying comorbid psychiatric disorders, and treatment options are extremely limited. In our study, it was aimed to investigate these variables and related factors in patients undergoing psychiatric evaluation and follow-up. METHOD: The study included 79 children and adolescents between the ages of 4 and 17 who were diagnosed with TTM and followed up in four different Child and Adolescent Psychiatry outpatient clinics between 2015 and 2020. The sociodemographic characteristics of these patients, clinical features of the disease, comorbid psychiatric disorders, and treatment approaches have been studied. RESULTS: Our results showed that TTM was more common in girls, hair and eyebrow plucking was the most common, and symptoms and features accompanying TTM changed with age, but not with gender. Again, 79.7% of these children had at least one psychiatric comorbid disorder (most common being anxiety disorders and Attention Deficit/Hyperactivity Disorder), comorbidity was closely related to TTM severity, 93.7% used at least one pharmacotherapeutic agent, and positive response rates to treatment were found to be low. Moreover, TTM severity was found to increase with age and disease duration. CONCLUSION: Study findings support that clinical presentation, disease severity and comorbidity rates may change with age in children and adolescents with TTM, and early intervention is important to prevent clinical progression/worsening and mental health sequela.

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.

Significance of family history in understanding and subtyping trichotillomania.

BACKGROUND AND AIMS: The existence of subtypes of trichotillomania (TTM) have long been hypothesized, and recent studies have further elucidated characteristic subtypes of TTM and possible ramifications of subtyping for treatment. In clinical applications of subtyping for treatment of TTM, family history (FH) of psychiatric disorders in patients may serve as a tool to differentiate disorder presentations and inform care. We compared prevalence of psychiatric illnesses in first-degree relatives of participants with TTM and healthy controls, respectively, in a large sample, and examined associations between those psychiatric disorders that were significantly different in the FH between groups and measures of disability, severity, and neuropsychological constructs. METHODS: We compared FHs of 152 participants (mean age = 29.9) with TTM and 71 healthy controls (mean age = 29.6), utilizing chi-squared tests to determine which psychiatric illnesses were more prevalent in FHs of participants with TTM. We then used two-tailed t-tests to compare TTM participants with those more prevalent FHs to participants without those FHs on measures of disorder severity, disability, and neuropsychological constructs. FINDINGS: Obsessive-compulsive disorder (OCD), TTM, skin picking disorder (SPD), and major depressive disorder (MDD) were significantly more frequent in first-degree relatives (p < 0.0033) of TTM participants than those of healthy controls. TTM participants with a FH of OCD scored significantly higher on measures of impulsivity and lower on measures of distress tolerance. Those with FH of TTM, SPD, and MDD did not differ significantly across measured variables. CONCLUSION: OCD, TTM, SPD, and MDD are more prevalent in the FHs of people with TTM, as compared to healthy controls. TTM participants with a family history of OCD may be more likely to demonstrate decreased distress tolerance and increased impulsivity. In all, as understanding of TTM subtypes develops, the FH may prove a useful tool in delineating subtypes and informing care.

Prevalence and gender distribution of trichotillomania: A systematic review and meta-analysis.

Epidemiological studies have provided varying prevalence estimates of trichotillomania (TTM) and other hair-pulling behaviors. We performed a systematic review and meta-analysis to provide data-driven prevalence estimates of TTM and hair-pulling. PubMed, PsycInfo and Embase were searched on June 2020 (updated in November 2021). Studies reporting the frequency of TTM defined by Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria or hair-pulling behaviors were included. Prevalence data was extracted for both genders, and female-to-male odds ratios (OR) were computed for TTM and any hair-pulling behaviors. Data were pooled through random-effects meta-analyses. Of the 713 records identified through database searches, 30 studies involving 38,526 participants were included. Meta-analyses indicated TTM had a prevalence of 1.14% (95% CI 0.66%, 1.96%), while any hair-pulling behavior had a prevalence of 8.84% (95% CI 6.33%, 12.20%). Meta-analyses demonstrated females were at an increased risk of any hair-pulling when noticeable hair loss was required (OR = 2.23, 95% CI 1.60, 3.10, p < 0.0001), but not of any hair-pulling when noticeable hair loss was not required (OR = 0.90, 95% CI 0.72, 1.64, p = 0.33). Meta-analyses did not indicate female preponderance in TTM (k = 10; N = 22,775; OR = 1.29; 95% CI 0.91, 1.83; I2 = 28%, p = 0.15), although there was considerable heterogeneity across studies. This study demonstrates that TTM impacts ∼1% of the population, while general hair-pulling behaviors affects ∼8%, highlighting the significant public health impact of this understudied condition. Additional research should clarify the gender distribution of TTM in epidemiological samples.

Autistic traits in trichotillomania.

INTRODUCTION: Although many variables have been examined as potentially contributing to the manifestation of trichotillomania (TTM), little research has focused on problems in social interactions. Hair pulling has many similarities to the stereotypies seen in autism spectrum disorders (ASD), and thus the present study examined autistic traits in adults with trichotillomania. METHODS: Fifty nontreatment-seeking adults with DSM-5 TTM were recruited. Participants completed standard diagnostic interviews, basic demographic information, and symptom inventories about TTM. Autistic traits were quantified using the Brief Autism- Spectrum Quotient (AQ-10) which screens for autistic traits. RESULTS: The sample comprised 50 participants, mean (standard deviation) age of 30.2 (5.6) years, 10% being male, 86% female, and 4% nonbinary. Eight of the participants had a history of major depressive disorder and six had a history of an anxiety disorder. No one had current or lifetime obsessive-compulsive disorder. The mean AQ10 score was 3.5 (2.0), with 14.6% scoring 6 or greater. Autism scores correlated significantly only with family dysfunction and not with symptom severity or impulsivity. CONCLUSIONS: This study examined autistic traits in a community-based sample of adults with TTM and found elevated rates of probable ASD (based on a self-report screening tool) among those with TTM. These results highlight the need to carefully screen for autistic traits in those with TTM. To what extent these traits may influence response to treatment, however, remains unclear.

Comorbid trichotillomania and attention-deficit hyperactivity disorder in adults.

BACKGROUND: Individuals with trichotillomania (TTM), a disorder characterized by repetitive pulling out of one's own hair, often have co-occurring ADHD, but little is known about this comorbidity. Additionally, there have been intimations in the literature that treatment of ADHD with stimulants may worsen TTM symptoms. This study aims to examine clinical aspects of individuals with TTM and co-occurring ADHD. METHODS: 308 adults with a current diagnosis of TTM were assessed for ADHD using the Mini International Neuropsychiatric Interview 7.0.2 and Adult ADHD Self Report Scale. Participants also completed clinical measures related to TTM severity, impulsivity, quality of life, and psychosocial dysfunction. A series of analyses of variance were used to calculate differences in scale scores among subjects with and without co-occurring ADHD. RESULTS: Of the 308 participants, 47 (15.3%) met the clinical threshold for ADHD. Participants with ADHD reported significantly higher scores in all first and second factor traits of impulsivity, including attentional impulsiveness (p < .0001), motor impulsiveness (p < .0001), and non-planning impulsiveness (p < .0001). Interestingly, participants with ADHD did not report significant differences in TTM severity, perceived quality of life, or functional impairment, regardless of medication status. DISCUSSION: The data suggest that ADHD is common in adults with TTM, and the comorbidity is associated with heightened impulsivity. The co-occurrence of ADHD does not affect individuals' quality of life, symptom severity, or functionality. Taking stimulant medications for ADHD also did not appear to affect TTM severity, despite past case reports suggesting these medications may lead to onset or worsening of TTM.

[Trichotillomania].

Trichotillomania (TTM) is associated with great psychosocial impairment and reduced quality of life and the lifetime prevalence is 1-3 %. The purpose of this review is to give an up-to-date overview of TTM. It describes the genesis and epidemiology of trichotillomania (TTM), including prevalence in terms of age and gender. The knowledge on the aetiology, phenomenology, and comorbidity of TTM is reviewed. The state of treatment options and implications, the effect of these and the clinical and research related perspectives are presented.

Skin picking disorder: Does a person's sex matter?

BACKGROUND: Skin picking disorder (SPD) is characterized by recurrent picking with scarring or tissue damage. Although research suggests that less than one-half of people with SPD are male, there is little clinical information about men with SPD. METHODS: We recruited 95 non-treatment-seeking adults as part of a cross-sectional study of SPD. Men (n = 17) and women (n = 78) with SPD were compared on clinical and cognitive measures. Sex differences in the demographic and clinical characteristics, skin picking sites, and presence of comorbidities were examined using analysis of variance for continuous variables and likelihood ratio Chi-square tests for categorical variables. RESULTS: Men were significantly more likely than women to report a first-degree relative with skin picking or hair pulling disorders (P = .0174). Men were less likely to pick from their scalps and backs and picked from fewer sites. Men and women did not significantly differ on skin picking severity, disability, impulsivity, or quality of life. CONCLUSIONS: These data indicate that SPD is similarly impairing for men and women, but men may have higher familial loading and a somewhat different distribution and frequency of picking sites. Sex differences in SPD merit more detailed consideration in larger samples, including addressing potentially higher genetic/familial loading in males.