Emotion regulation and other psychological models for body-focused repetitive behaviors

Interoception, emotion regulation strategies and skin-picking behaviors - Results of an intensive longitudinal study

Compulsive skin-picking is associated with emotion regulation difficulties, whose origins remain unclear. Interoception, plays an important role in effective emotion regulation. This study examined the relationship between interoception, emotion regulation strategies, and skin-picking in 136 individuals (85% women, aged 18-41), including 71 engaging in skin-picking and 65 psychologically healthy controls. We were interested in between-group differences in maladaptive and adaptive emotion regulation and aspects of interoception as well as associations of the latter with skin-picking symptoms and use of emotion regulation strategies. At baseline, we assessed habitual emotion regulation strategies (rumination, suppression, distraction, engagement, arousal control, reappraisal) and Interoceptive Sensibility (e.g., emotional awareness, body listening, self-regulation, noticing) through self-report questionnaires. Moreover, Interoceptive Accuracy (IAc) was measured via a Heartbeat Counting Task. Additionally, Ecological Momentary Assessment (EMA) over seven days was used to register use of emotion regulation strategies and the occurrence and severity of skin-picking episodes during that period. At baseline, the skin-picking group exhibited lower IAc, emotional awareness, and higher habitual use of rumination than control group. Lower IAc was associated with higher odds of reporting skin-picking episodes assessed during EMA. Body listening correlated with a reduced sense of control over skin-picking during EMA. In total sample, self-regulation was related to lower odds of using rumination during EMA and noticing with less use of cognitive reappraisal. The study highlights the complex relationship between interoception, emotion regulation, and skin-picking, offering new insights into the mechanisms underlying skin picking disorder.

Developing and Evaluating a Situated Assessment Instrument for Trichotillomania: The SAM2 TAI

Measuring trichotillomania is essential for understanding and treating it effectively. Using the Situated Assessment Method (SAM2), we developed a psychometric instrument to assess hair pulling in situations where it occurs. In two studies, pullers evaluated their pulling in relevant situations, along with how much they experience factors that potentially influence it (e.g., external triggers, reduction in negative emotion, negative self-thoughts). Individual measures of pulling, averaged across situations, exhibited high test reliability, construct validity, and content validity. Large differences between situations in pulling were observed, along with large individual-situation interactions (with limited evidence distinguishing focused versus automatic pulling subtypes). In linear regressions for individual participants, factors that influence pulling tended to correlate with pulling as predicted, explaining a median 74%-83% of its variance. By identifying factors that predict pulling for each individual across situations, the SAM2 Trichotillomania Assessment Instrument (TAI) offers a rich understanding of an individual's pulling experience, potentially supporting individualized pulling interventions.

Exploring pharmacological treatment for trichotillomania: do we need better education?

BACKGROUND

Trichotillomania, also known as hair-pulling disorder, is a chronic psychiatric condition with a fluctuating course in which an individual pulls out their hair, leading to visible hair loss and psychosocial sequelae. Due to the unknown pathogenesis, the treatment of this disorder is complex and remains a challenge for dermatologists and psychiatrists. Since guidelines for treating trichotillomania are lacking and, consequently, no common treatment strategy exists, we decided to perform a large-scale, global retrospective cohort study to assess the characterized real-world prescription patterns in treating trichotillomania.

METHODS

The research used the TrinetX database for patients with trichotillomania (ICD 10 - F63.3) within the European and the United States Collaborative Network (EC and UC, respectively). After consulting with a psychodermatology expert, a list of 25 medications was investigated.

RESULTS

Data on the prescription drugs of 1,275 patients from the EC and 109,741 patients from the UC were collected. In both the EC and UC cohorts, benzodiazepine derivatives, particularly lorazepam and midazolam, were the most commonly prescribed sedatives/hypnotics. Antipsychotic prescriptions, primarily haloperidol, followed benzodiazepines. After the trichotillomania diagnosis, notable changes in drug prescriptions for the EC cohort, including an increased likelihood of receiving acetylcysteine, haloperidol, quetiapine, sertraline, olanzapine, and risperidone were observed. The UC cohort showed minimal changes. Overall, both cohorts leaned toward benzodiazepine prescriptions (37% UC, 21% EC) and had limited antidepressant usage. Haloperidol (19.3%) and quetiapine (15.1%) were commonly prescribed in both cohorts.

CONCLUSIONS

The results of our study indicate that the real-world prescription patterns for trichotillomania differ significantly from the expert-proposed therapeutic approach and point toward the necessity of creating standards of pharmacological care and better education.

Long-term follow-up of acceptance-enhanced behavior therapy for trichotillomania

Acceptance-enhanced behavior therapy for trichotillomania (AEBT-TTM) is effective in reducing trichotillomania (TTM) symptoms, but the durability of treatment effects remains in question. This study analyzed 6-month follow-up data from a large randomized clinical trial comparing AEBT-TTM to an active psychoeducation and supportive therapy control (PST). Adults with TTM (N=85; 92% women) received 10 sessions of AEBT-TTM or PST across 12 weeks. Independent evaluators assessed participants at baseline, post-treatment, and 6 months follow-up. For both AEBT-TTM and PST, self-reported and evaluator-rated TTM symptom severity decreased from baseline to follow-up. TTM symptoms did not worsen from post-treatment to follow-up. At follow-up, AEBT-TTM and PST did not differ in rates of treatment response, TTM diagnosis, or symptom severity. High baseline TTM symptom severity was a stronger predictor of high follow-up severity for PST than for AEBT-TTM, suggesting AEBT-TTM may be a better option for more severe TTM. Results support the efficacy of AEBT-TTM and show that treatment gains were maintained over time. Although AEBT-TTM yielded lower symptoms at post-treatment, 6-month follow-up outcomes suggest AEBT-TTM and PST may lead to similar symptom levels in the longer term. Future research should examine mechanisms that contribute to long-term gain maintenance.

The association between trichotillomania symptoms and emotion regulation difficulties: A systematic review and meta-analysis

BACKGROUND

Emotion regulation is postulated to play an important role in Trichotillomania (TTM). Whilst a growing number of studies have examined the relationship between emotion regulation difficulties and TTM symptoms, there have been no attempts to evaluate the overall strength of this association or the quality of the evidence base.

METHOD

This systematic review and meta-analysis aimed to synthesise findings from studies that have examined the relationship between emotion regulation difficulties and TTM symptoms, to inform future TTM treatment targets. We identified 17 studies that met inclusion criteria. From these studies, 32 correlation coefficients were extracted for meta-analysis. The Joanna Briggs Institute Checklist for Analytical Cross Sectional Studies was used to assess risk of bias amongst the included studies.

RESULTS

There was a moderately sized association between TTM symptoms and ER difficulties, (r adjusted = 0.32, 95 % CI [0.28, 0.37], t = 15.58 (df = 11.86), p < 0.0001) that was moderated by sample size (F(df1 = 1, df2 = 30) = 4.597, b = -0.0001, SE = 0.0001, 95 % CI [-0.0002; 0.0000], p = 0.040) and differences between types of emotion regulation measures (Q(df = 1) = 4.06, p = 0.044).

LIMITATIONS

The data analysed was correlational, therefore causality was unable to be determined. Comorbidities were not able to be examined as a moderator.

CONCLUSION

This study provided a preliminary integration of the evidence and demonstrated that individuals with higher levels of TTM severity appear to exhibit decreased overall emotion regulation abilities and strategies.

Psychological distress and the belief that oral behaviours put a strain on the masticatory system in relation to the self-report of awake bruxism: Four scenarios

BACKGROUND

It is assumed that other factors than masticatory muscle activity awareness could drive the self-report of awake bruxism.

OBJECTIVES

To investigate the extent to which the report of awake bruxism is associated with psychological distress, and with the belief that oral behaviours put a strain on the masticatory system among TMD-pain patients.

MATERIALS AND METHODS

The study sample consisted of 1830 adult patients with reported function-dependent TMD pain. Awake bruxism was assessed through six items of the Oral Behaviors Checklist. Psychological distress was assessed by means of somatic symptoms, depression and anxiety. Causal attribution belief was measured with the question 'Do you think these behaviours put a strain on your jaws, jaw muscles, and/or teeth?'

RESULTS

Mean age of all participants was 42.8 (±15.2) years, 78.2% being female. Controlled for sex, positive, yet weak, correlations were found between awake bruxism and somatic symptom severity (rs  = 0.258; p < .001), depression (rs  = 0.272; p < .001) and anxiety (rs  = 0.314; p < .001): patients with the highest scores reported approximately twice as much awake bruxism compared to those with minimal scores. Controlled for age and sex, a positive, moderate correlation was found between awake bruxism and causal attribution belief (rs  = 0.538; p < .001). Patients who believed that performing awake oral behaviours put 'very much' a strain on the masticatory system reported four times more awake bruxism than patients who did not believe that these behaviours are harmful.

CONCLUSIONS

Based on the results and relevant scientific literature, the theoretical background mechanisms of our findings are discussed in four scenarios that are either in favour of the use of self-report of awake bruxism being a representation of masticatory muscle activity awareness, or against it.

Self-induced nail disorders (SINDs): What do we know so far?

Self-induced nail disorders are a broad group of different clinical manifestations that share the common trait of being caused more or less voluntarily by the patient. These are distinct conditions within the clinical spectrum of onychotillomania. Most patients diagnosed with these disorders have psychiatric co-morbidities, and a multidisciplinary approach is thus highly recommended. The purpose of this review is to describe the most common clinical features encountered during daily nail consultations and to provide useful diagnostic tools and therapeutic tips for the best approach to these conditions.

Habit-reversal training: a psychotherapeutic approach in treating body-focused repetitive behaviour disorders

Body-focused repetitive behaviours (BFRBs) are recurrent, compulsive, destructive behaviours directed towards the body. Although studies have demonstrated a 12-14% prevalence rate, researchers found that dermatologists and psychiatrists show a lack of knowledge regarding psychodermatology resources and information about BFRB disorders (BFRBDs) such as trichotillomania (TTM). There is limited research about treatments including ones investigating the clinical applications of various self-help training such as decoupling (DC) and DC in sensu (DC-is) as well as about habit-reversal training (HRT). HRT is a five-component behavioural intervention that aims to develop a competing response to a specific unwanted behaviour. Studies have found substantial support for HRT's efficacy in treating a variety of maladaptive repetitive behaviours including onychotillomania, TTM, skin-picking disorder and chronic cheek biting. Additionally, many psychotherapies can augmented HRT. Psychotherapies include acceptance and commitment therapy, dialectical behaviour therapy, psychodynamic psychotherapy, mindfulness mediation and the cognitive psychophysiological model. A recently investigated variant of HRT, DC-is, resulted in consistently satisfactory objective and subjective improvement for treating BFRBDs, and HRT showed good subjective but poor objective improvement compared with standard DC. HRT and HRT variants are effective therapeutic treatments for BFRBDs; however, further randomized double-blinded and placebo-controlled trials are required to examine HRT's therapeutic profile.

Sleep Disturbances in Pediatric Body-Focused Repetitive Behaviors: A Preliminary Investigation

Body-focused repetitive behaviors (BFRBs) are repeated actions to one's body resulting in physical damage. Limited research has examined sleep, a known factor in psychological health, within the context of pediatric BFRBs. The current study sought to explore the connection between disordered sleep and BFRBs in a community sample. Aim 1 of the study was to determine the predictive power of group membership [control group (no BFRB symptoms reported), subthreshold BFRB group (mild BFRB symptoms reported; severity score of 2 or less out of 9), and those with symptoms characteristic of BFRBs (more than mild BFRB symptoms reported; severity score of 3 or higher out of 9)] for level of sleep disturbance. A hierarchical regression revealed that there was a significant effect of group membership after controlling for anxiety (F (3, 410) = 152.976, p < .001). Aim 2 of the study was to test whether there was a relationship between sleep disturbance and BFRB severity. The hierarchical regression revealed that at Step 1, anxiety accounted for 23.1% of the variance in BFRB severity (β = 0.48, t = 8.87, p < 0.001). At Step 2, sleep disturbance total score accounted for an additional 7.2% of the variance, suggesting this variable makes a unique contribution to overall BFRB severity (SDSC: β = 0.40, t = 5.18, p < 0.001). The findings of this study suggest that sleep could be a clinical factor to consider when conceptualizing a child with BFRBs.

Short-term intervention complemented by wearable technology improves Trichotillomania - A naturalistic single-case report

There is a growing interest in using wearable technology for the treatment of body-focused repetitive behaviors (BFRBs), such as Trichotillomania. Yet, to our knowledge, few studies address the applicability and use of wearable technology as a therapeutic element in more naturalistic situations. Here we would like to introduce its potential use combined with a Habit-Reversal Training in a single-case experimental design. In practice, individuals with BFRBs frequently show complex constellations of psychiatric disorders. Accordingly, the here presented participant was diagnosed with Trichotillomania as well as comorbid ADHD and examination phobia. The participant was offered to wear an unobtrusive and user-friendly vibration device that sent an alarm when her critical hairpulling behaviors occurred. The complementing Habit-Reversal Training included an Awareness Training supported by the vibration alarm of the wearable device. It further included a Competing Response Training by learning benign behaviors that could replace the hairpulling behavior. The frequency of hairpulling episodes was assessed using daily self-reports and by using the monitoring function of the wearable device. The intervention procedure was implemented into the participant's everyday life and evaluated over the course of 214 days. The results indicated a significant reduction in the daily episodes of hair pulling. Our preliminary findings suggest that the here applied intervention has the potential to effectively treat Trichotillomania in individuals with comorbid disorders in psychotherapeutic outpatient care. Certainly, group-studies will need to further validate the approach's effectiveness.

Hair pulling disorder and skin picking disorder have relatively limited associations with negative emotionality: A meta-analytic comparison across obsessive-compulsive and related disorders

The obsessive-compulsive and related disorders (OCRD) chapter in DSM-5 includes two relatively distinct groups of disorders: (1) Compulsive disorders [i.e., obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), hoarding disorder (HD)] and (2) grooming disorders [i.e., skin picking disorder (SPD) and hair pulling disorder (HPD)]. The two groups may relate differently with negative emotionality; however, the literature has produced mixed findings. The current study sought to quantify the concurrent association between negative emotionality and each of the five OCRDs. We conducted systematic reviews of research reporting correlations between (1) negative emotionality (i.e., depression, anxiety, stress, negative affect, and neuroticism) and (2) severity of OCRD symptoms in both clinical and non-clinical adult samples. We used three-level meta-analytic models to estimate the size of the correlations. Negative emotionality had robust positive correlation with symptoms of OCD [k = 156, r = 0.44, 95% CI= 0.43-0.46], BDD [k = 58, r = 0.45, 95% CI= 0.43-48], and HD [k = 67, r = 0.39, 95% CI= 0.36-0.42] but significantly smaller correlation with SPD [k = 31, r = 0.31, 95% CI= 0.27-0.34] and HPD [k = 24, r = 0.28, 95% CI= 0.25-0.32]. Overall, the results indicate that grooming disorders have relatively limited associations with negative emotionality. Implications for classification of OCRDs within the broader taxonomy of psychopathology are discussed.

The problem with picking: Permittance, escape and shame in problematic skin picking

OBJECTIVES

Problematic skin picking (SP) is a poorly understood experience characterised by a drive to pick the skin and related psychosocial impact. In the DSM-5, problematic SP is classified as 'excoriation (skin picking) disorder'. The aim of this article is to present a rare qualitative perspective on the lived experience of problematic SP, prioritising participants' voices and sense-making.

DESIGN

An in-depth qualitative study of individuals who self-identified as picking their skin problematically and experienced related distress.

METHODS

Seventeen UK-based participants were recruited online and interviewed about their SP. Participants were given choice of interview modality, including instant messenger platforms, telephone, email and Skype, to maximise comfort and improve the accessibility of the study. Transcripts were analysed using thematic analysis.

RESULTS

Three themes offering novel insight into the phenomenology of participants' SP are highlighted and explored: (1) how cognitions and circumstances drove and permitted SP, (2) how participants 'zoned out' while SP and the escape or relief that this attentional experience offered and (3) participants' feelings of shame and distress in how they felt their SP may appear to others.

CONCLUSIONS

This study contributes in-depth and novel ideas to the understanding of SP phenomenology and identifies how environmental factors, cognitions, contextual distress and shame may be considerations in therapeutic intervention. It presents the complexity of SP sense-making and demonstrates the need for individual formulation.

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.

Appearance-related concerns in individuals with pathological skin picking-a comparison with individuals with dermatological conditions and skin-healthy controls

Introduction

Pathological skin picking (PSP) is an excessive behavior which characterizes Skin Picking Disorder. Individuals repeatedly pick their skin and cause skin lesions, but are unable to control the behavior, which can cause severe distress. Visible self-inflicted skin lesions can additionally affect individuals with PSP due to emerging appearance-related concerns. However, these concerns and their role in PSP have hardly been studied, especially not in comparison with individuals with dermatological conditions and skin-healthy controls.

Methods

The present cross-sectional study (n = 453, 83.9% female, 15.9% male, 0.2% diverse) aimed at analyzing appearance-related concerns and mental health outcomes between four groups: Individuals with PSP and dermatological conditions (SP/DC; n = 83), PSP without dermatological conditions (SP; n = 56), dermatological conditions without PSP (DC; n = 176) and skin-healthy controls (SH, n = 138). We compared questionnaire data on dysmorphic concerns, appearance-based rejection sensitivity, and body dysmorphic symptoms, as well as PSP-symptoms and mental health outcomes (depression, anxiety, and self-esteem) between groups.

Results

The analyses showed a significant multivariate group effect in the appearance-related variables, F(6, 896) = 19.92, Wilks' Λ = 0.78, p < 0.001, and mental health outcomes, F(6, 896) = 16.24, Wilks' Λ = 0.81, p < 0.001. The SP/DC group had the strongest appearance-related concerns and mental health impairments, followed by the SP group, the DC group and the SH group. The SP/DC group and SP group only differed significantly with regard to dysmorphic concerns, but not in other variables. The DC group was less affected but still showed higher dysmorphic concerns and mental health impairments than skin-healthy controls. In contrast to the PSP groups, the other two groups did not exceed clinically relevant cut-off scores.

Discussion

The present study shows that individuals with PSP exhibit strong appearance-related concerns, regardless of the presence or absence of underlying or comorbid dermatological conditions. These findings shed new light on the importance of appearance-related concerns in Skin Picking Disorder and the role of PSP as a potentially overlooked risk factor in dermatological patients. Therefore, appearance-related concerns should be explicitly addressed in dermatological and psychotherapeutic settings. Future studies should also include longitudinal and experimental analyses to more clearly classify the role of appearance-related concerns in the etiology of PSP and Skin Picking Disorder.

Excitatory SST neurons in the medial paralemniscal nucleus control repetitive self-grooming and encode reward

The use of body-focused repetitive behaviors (BFRBs) is conceptualized as a means of coping with stress. However, the neurological mechanism by which repetitive behaviors affect anxiety regulation is unclear. Here, we identify that the excitatory somatostatin-positive neurons in the medial paralemniscal nucleus (MPL^SST neurons) in mice promote self-grooming and encode reward. MPL^SST neurons display prominent grooming-related neuronal activity. Loss of function of MPL^SST neurons impairs both self-grooming and post-stress anxiety alleviation. Activation of MPL^SST neurons is rewarding and sufficient to drive reinforcement by activating dopamine (DA) neurons in the ventral tegmental area (VTA) and eliciting dopamine release. The neuropeptide SST facilitates the rewarding impact of MPL^SST neurons. MPL^SST neuron-mediated self-grooming is triggered by the input from the central amygdala (CeA). Our study reveals a dual role of CeA-MPL^SST-VTA^DA circuit in self-grooming and post-stress anxiety regulation and conceptualizes MPL^SST neurons as an interface linking the stress and reward systems in mice.

The Generic BFRB Scale-8 (GBS-8): a transdiagnostic scale to measure the severity of body-focused repetitive behaviours

BACKGROUND

Body-focused repetitive behaviours (BFRBs) such as skin picking and hair pulling are frequent but under-diagnosed and under-treated psychological conditions. As of now, most studies use symptom-specific BFRB scales. However, a transdiagnostic scale is needed in view of the high co-morbidity of different BFRBs.

AIMS

We aimed to assess the reliability as well as concurrent and divergent validity of a newly developed transdiagnostic BFRB scale.

METHOD

For the first time, we administered the 8-item Generic BFRB Scale (GBS-8) as well as the Repetitive Body Focused Behavior Scale (RBFBS), modified for adults, in 279 individuals with BFRBs. The GBS-8 builds upon the Skin Picking Scale-Revised (SPS-R), but has been adapted to capture different BFRBs concurrently. A total of 170 participants (61%) were re-assessed after 6 weeks to determine the test-retest reliability of the scale.

RESULTS

Similar to the SPS-R, factor analysis yielded two dimensions termed symptom severity and impairment. The test-retest reliability of the scale was satisfactory (r = .72, p<.001). Concurrent validity (r = .74) with the RBFBS was good (correlational indexes for concurrent validity were significantly higher than that for discriminant validity).

DISCUSSION

The GBS-8 appears to be a reliable and valid global measure of BFRBs. We recommend usage of the scale in combination with specific BFRB scales to facilitate comparability across studies on obsessive-compulsive spectrum disorders.

Altered Intrinsic Regional Spontaneous Brain Activity in Patients With Severe Obesity and Meibomian Gland Dysfunction: A Resting-State Functional Magnetic Resonance Imaging Study

Purpose

To evaluate potential regional homogeneity (ReHo) cerebrum function lesions in people with severe obesity and meibomian gland dysfunction (SM) and probe the connection between aberrant cerebrum activity and clinical manifestations.

Patients and Methods

An aggregation of 12 patients with SM, and 12 healthy controls (HCs) closely matched in age and gender were enrolled. We applied corneal confocal microscopy and fundus angiography to compare imaging distinctions between the two groups. SMs were required to carefully fill out the Hospital Anxiety Depression Scale (HADS) forms, and a correlation analysis was performed. ReHo was also utilized to appraise partial differences in spontaneous cerebrum function. Receiver operating characteristic (ROC) curves were created to partition ReHo values between patients with SM and the HCs.

Results

ReHo values for the left cerebellum (LC), right fusiform gyrus (RFG), left inferior temporal gyrus (LITG), left rectus gyrus (LRG), right thalamus (RT), right caudate (RC), left insula (LI), and left thalamus (LT) of subjects with SM were notably higher than those of the HCs (P < 0.05). ReHo values of the right middle frontal gyrus (RMFG) in subjects with SM were decreased notably compared to the HCs (P < 0.05). ReHo values for the RMFG showed a negative correlation with the anxiety scores (ASs; r = −0.961, P < 0.001) and ReHo values for the RFG showed a positive correlation with the depression scores (DSs; r = 0.676, P = 0.016). The areas under the ROC curve were 1.000 (P < 0.001) for the RMFG, LC, LITG, LRG, RC, LI, and LT and 0.993 (P < 0.001) for the RFG and RT. The results from the ROC curve analysis indicated that changes in the ReHo values of some brain regions may help diagnose SM.

Conclusion

Our research emphasized that patients with SM had lesions in synchronized neural activity in many encephalic areas. Our discoveries may provide beneficial information for exploring the neuromechanics of SM.

Emotion regulation and tic disorders in children

Tic disorders (TD) are developmental neuropsychiatric conditions often accompanied by comorbid conditions, and psychosocial hardships for child and family. The etiology of tics is unknown, and is complex and multifactorial. Stress is known to aggravate tic expression as well as associated comorbidities. Consequently, this study focused on possible connections between stress, emotion regulation, tic expression, and related psychopathology. Sixty consecutive admissions were assessed for perceived stress, emotional dysregulation, severity of obsessions and compulsions, anxiety, depression, attention deficit disorder, and tic expression at a TD clinic, in a university affiliated pediatric hospital. The results indicated that stress and emotion dysregulation were significantly related to both tic expression and severity of comorbidities. We discuss the role of emotion regulation dimensions regarding TD and related psychopathology as well as the mediating role of emotion regulation, and how they may contribute to the development of improved therapies for children with TD.

Pathological Skin Picking: Phenomenology and Associations With Emotions, Self-Esteem, Body Image, and Subjective Physical Well-Being

Pathological skin picking (PSP) refers to the repetitive manipulation of the skin causing wounds, scars, emotional distress, and social impairment. Skin picking disorder was first recognized as a distinct disorder in the DSM-5 and is still understudied in terms of phenomenology, etiology, and associated consequences. However, the body-related pathology suggests that the relation to the own body might be a crucial factor in PSP. Previous studies provided first insights that affected individuals show a more negative body image and lower self-esteem than healthy individuals. The present study sought to investigate skin picking phenomenology, related emotions as well as associations with self-esteem, body image, and subjective physical well-being. The study was conducted as an open online study, and recruitment was generally targeted to individuals of full age and in addition specifically to individuals with PSP. A total of 363 individuals (82.9% female; age: M = 32.6, SD = 13.92) participated and answered various self-report measures. Nearly half of the sample exceeded the cutoff score for pathological skin picking (N = 163; 44.9%). The results suggest that boredom, bodily tension and strong negative feelings often precede PSP episodes. During the episode most individuals seem to experience a loss of control, trance and positive feelings. After the PSP episode, shame, guilt, anger and anger toward themselves are most prominent. As expected, skin picking severity was positively associated with body image disturbances and negatively with self-esteem, and subjective physical well-being. When controlling for depressive symptoms, all associations were reduced, but those with body image disturbances (r = 0.44; p < 0.001), self-esteem (r = -0.27; p < 0.001), subjective physical well-being (r = -0.22; p < 0.001), and peace of mind (r = 0.30; p < 0.01) remained significant. Moreover, greater skin damage due to skin picking was moderately associated with higher body image disturbances. The results indicate that PSP severity is associated with a negative body image and low self-esteem, and suggest that it may be warranted to consider these aspects in the development of future interventions for PSP. However, relations with body image and self-esteem should be examined in longitudinal studies investigating causal relationships between body image, self-esteem and skin picking. Moreover, PSP phenomenology and the role of specific emotions should be investigated in more detail.

Trichotillomania and Skin-Picking Disorder: An Update

Trichotillomania (hair pulling disorder) and skin-picking (excoriation) disorder are common neuropsychiatric disorders (each with a point prevalence of around 2%) but are underrecognized by professionals. Affected individuals repeatedly pull out their own hair or pick at their skin, and these symptoms not only have a negative impact on these individuals because of the time they occupy but can also lead to considerable physical disfigurement, with concomitant loss of self-esteem and avoidance of social activities and intimate relationships. The behaviors may also have serious physical consequences. Trichotillomania and skin picking frequently co-occur, and both disorders commonly present with co-occurring depression, anxiety, impulsive, and obsessive-compulsive disorders. Behavioral therapy currently appears to be the most effective treatment for both. Pharmacotherapy, in the form of N-acetylcysteine or olanzapine, may also play a role in treatment.

Dissociative Experiences Mediate the Relationship Between Traumatic Life Events and Types of Skin Picking. Findings From Non-clinical Sample

Aim: Skin-picking (excoriation) disorder is considered as a form of maladaptive coping methods used by individuals who have difficulties in applying more adaptive strategies. Skin-picking development has been suggested to be preceded by traumatic life events. Dissociative symptoms have been reported as experienced by skin-picking sufferers during picking episodes. The purpose of the study was to examine whether the link between trauma and automatic type of skin-picking is mediated by the frequency of dissociative experiences, and whether the COVID-19 pandemic conditions have changed this relationship in any way. Methods: The study sample consisted of 594 adults (76% women) aged from 18 to 60. Traumatic life events, dissociative experiences, and types of skin-picking (focused vs. automatic) were assessed with self-report questionnaires. Mediation analyses and multigroup path analyses were carried out. Results: Dissociative experiences partially mediated the link between traumatic events and both types of skin-picking. The model was robust considering the conditions in which survey was filled out (pre-pandemic vs. pandemic). Conclusions: Traumatic life events and dissociative experiences are associated with both automatic and focused skin-picking regardless of pandemic conditions. Further studies are needed to understand mechanisms underlying the relationship between dissociation and skin-picking styles.

Hair-Pulling Does Not Necessarily Serve an Emotion Regulation Function in Adults With Trichotillomania

Background: Trichotillomania (TTM) has been associated with childhood trauma and perceived stress. While it has been hypothesized that hair-pulling regulate negative emotions, the relationship between childhood trauma, perceived stress, emotion regulation, and hair-pulling has not been well-studied.

Methods: Fifty-six adults with TTM and 31 healthy controls completed the Childhood Trauma Questionnaire (CTQ), Perceived Stress Scale (PSS), and Difficulties in Emotion Regulation Scale (DERS). Hair-pulling severity was measured with the Massachusetts General Hospital-Hair Pulling Scale. CTQ, PSS, and DERS total scores were compared across groups using ANCOVA and the correlation between hair-pulling severity and emotion dysregulation was determined. Regression analyses were used to estimate the association of CTQ and PSS totals with DERS, and to determine whether associations between predictors and dependent variable (DERS) differed across groups.

Results: TTM patients reported higher rates of childhood trauma (p <= 0.01), perceived stress (p = 0.03), and emotion dysregulation (p <= 0.01). There was no association between emotion dysregulation and pulling severity (r = −0.02, p = 0.89). Perceived stress was associated with emotion dysregulation in both groups (p < 0.01), and no association between childhood trauma and emotion dysregulation in either group. Perceived stress was the only significant predictor of emotion dysregulation in both groups (F = 28.29, p < 0.01).

Conclusion: The association between perceived stress and emotion dysregulation is not specific to TTM, and there is no association between emotion dysregulation and hair-pulling severity, suggesting that key factors other than emotion dysregulation contribute to hair-pulling. Alternative explanatory models are needed.

Development of the social concerns in individuals with body-focused repetitive behaviors (SCIB) scale

Body-focused repetitive behaviors (BFRBs) include such disorders as compulsive hair pulling, skin picking, nail biting, and cheek biting, which can lead to significant psychosocial impairment (American Psychiatric Association, 2013). As such, social concerns (i.e., concerns about how others view their behavior or affected body sites) are common in these individuals, and may significantly associate with BFRB symptomology (Snorrason et al., 2012). Currently, there are no measures to adequately assess social concerns specific to BFRBs. To this end, we developed a new self-report measure called the Social Concerns in Individuals with BFRBs (SCIB) that aimed to assess these concerns using two independent samples of individuals reporting elevated BFRB symptoms. Results showed that the overall level of social concerns reported on the SCIB significantly explained the variance in hair pulling and skin picking symptom severity even after controlling for the influence of other general social concern and emotional distress measures. Exploratory and confirmatory factor analyses provided psychometric evidence for the two-factor structure of the SCIB: (1) Concern about Physical Unattractiveness and (2) Concern about Social Disapproval, which were found to assess distinguishable aspects of BFRB-relevant social concerns. Overall, the findings suggest that the SCIB is a useful measure that can be used to evaluate social concerns in those with BFRB disorders.

The Role of Self-Criticism and Shame in Body-Focused Repetitive Behaviour Symptoms

Body-focused repetitive behaviours (BFRBs), such as hair-pulling, skin-picking, and nail-biting, are non-functional habits associated with difficulties in emotion regulation. Although several models have been developed to explain the difficulties experienced by people suffering from BFRBs, a number of cognitive and emotional processes have yet to be explored. This study sought to investigate the psychological characteristics involved in the development and maintenance of BFRB symptoms. In particular, we aimed to evaluate the relationship of self-criticism, shame, and maladaptive cognitive emotion strategies with symptoms and examine if the relationship between perfectionism and symptoms was mediated by self-criticism and shame. Seventy-six participants from a community sample completed a number of self-report measures. Findings from our multivariate linear regression model supported that shame and maladaptive cognitive emotion regulation strategies significantly predicted BFRB symptoms. Results of our mediational analyses revealed that shame significantly mediated the relationship between perfectionism and BFRB symptoms. Interventions that target shame may be beneficial for treating these conditions. Future studies should replicate these findings with clinical populations and other BFRB subtypes.

Body-focused repetitive behaviors in school-going children and adolescents and its relationship with state-trait anxiety and life events

BACKGROUND

Body-focused repetitive behaviors (BFRBs) are nonfunctional self-injurious behaviors. BFRBs fall under obsessive-compulsive and related disorders (OCRDs) and co-occur with anxiety disorders.

AIM

The current study plans to assess the presence of BFRBs in schoolchildren and adolescents and find its relationship with state-trait anxiety and significant life events.

MATERIALS AND METHODS

The study identified twenty-one students with BFRBs using the Modified Habit Questionnaire. Along with the 21 matched healthy controls, both the groups were evaluated on the State-Trait Anxiety Inventory for Children (STAIC) and Life Event Scale for Indian Children (LESIC).

RESULTS

The study group scored significantly high on STAIC state score (P = 0.004), trait score (P = 0.014), and total score (P = 0.020). On five life events, the study group reported significantly high on stress.

CONCLUSION

The study reports the presence of BFRBs in schoolchildren; state-trait anxiety and significant life events have a significant association with BFRBs.

Hair-pulling disorder (Trichotillomania): Etiopathogenesis, diagnosis and treatment in a nutshell

Hair-pulling disorder (Trichotillomania) is a disabling mental disorder. Patient's behavior is characterized by the recurrent pulling of own hair with hair loss and a marked dysfunction in various areas of daily life. Trichotillomania is a relatively common disorder with pediatric onset, often associated with significant morbidity, comorbidity, and functional decline. Surprisingly, children or adolescents have been little studied in the research studies on the pathophysiology and psychopathology of trichotillomania. Furthermore, more evidences regarding the effective and evidence-based pharmacological interventions for the treatment of this condition are encouraged. This narrative review will report on the etiopathogenesis and clinical manifestations of trichotillomania including criteria for diagnosis and treatment issues of this complex mental disorder.

Resting-State Functional Connectivity of Supplementary Motor Area Associated with Skin-Picking Symptom Severity

Pathological skin picking (excoriation) is a relatively common disorder. Although it has been hypothesized to share a similar pathophysiological basis as other obsessive-compulsive (OC) spectrum disorders, to date, little work has specifically examined the precise neurobiological mechanisms involved in excoriation. Disruption in functional circuits involving the right inferior frontal gyrus (rIFG) and supplementary motor area (SMA) may be particularly relevant to skin-picking pathology as these regions have been implicated in other OC-spectrum disorders for their roles in response inhibition and voluntary motor action, respectively. To this end, the present study examined the associations between skin-picking symptom severity and resting-state functional connectivity of the rIFG and bilateral SMA. Participants endorsing elevated symptoms of excoriation completed a self-report measure of symptom severity and resting-state functional magnetic resonance imaging scan. Results indicated that symptom severity was associated with weaker connectivity between the SMA and clusters within the orbitofrontal cortex and angular gyrus. Contrary to hypotheses, there were no effects of symptom severity on functional connectivity of the rIFG. Overall, these findings suggest that skin-picking symptom severity may be associated with disruption in higher-order motor networks contributing to deficits in top-down regulation of motor behavior.

Comprehensive Behavioral Therapy of Trichotillomania: A Multiple-Baseline Single-Case Experimental Design

Despite rapidly increasing knowledge about Trichotillomania (TTM), no gold-standard evidence-based psychological intervention has been identified. In the current study, we evaluated the potential efficacy of an eight-session psychological intervention for TTM, namely the Comprehensive Behavioral Model (ComB) treatment, using a multiple-baseline single-case experimental design with three Italian women with TTM. The study included three phases: baseline, intervention, and 3-month follow-up. We assessed the intervention using daily self-monitoring of number of hair-pulling episodes, number of pulled hairs per episode, degree of resistance to pulling urges, and degree of associated distress. We also assessed for reliable improvement in general distress from baseline to post-intervention. All participants completed treatment and showed improvements on those symptom measures that were most relevant to their individualized case conceptualization. However, no participants recovered completely or demonstrated reliable improvement in general distress. Our results provide initial evidence for the utility of the ComB treatment for TTM in an Italian clinical setting. Furthermore, they support the delivery of individualized and flexible psychological treatments when treating TTM.

Skin Picking in People with Prader-Willi Syndrome: Phenomenology and Management

Skin picking is highly prevalent in people with Prader-Willi syndrome (PWS). This study addressed the temporal (frequency, duration) and wider characteristics (e.g. type of skin picked, apparent motivations, or management strategies) of skin picking to inform intervention strategies. Nineteen parents/carers who observe skin picking shown by the person they care for completed a semi-structured interview. Results were consistent with previous research but advanced the field by finding that most participants picked skin with an imperfection and that parents/carers most commonly use distraction as a management strategy. Interventions that are behavioural, support emotion regulation and/ or are used in the typically developing population are therefore likely to be beneficial for future research.

Body-focused repetitive behaviors and non-suicidal self-injury: A comparison of clinical characteristics and symptom features

Body-focused repetitive behaviors (BFRBs) and non-suicidal self-injury (NSSI) are recognized as distinct categories in the DSM-5. However, definitions and assessment of NSSI sometimes encompasses behaviors similar to BFRBs, and little data exist about their clinical differences. The current study examined clinical characteristics and symptom features associated with NSSI vs. BFRBs. The current sample included 1523 individuals who endorsed moderate to severe NSSI (n = 165) or BFRBs: hair pulling group (n = 102), skin picking group (n = 216), nail picking group (n = 253), nail biting group (n = 487), and cheek biting group (n = 300). Responders were asked to complete questionnaires on clinical features relevant for BFRBs and NSSI. NSSI and BFRBs had significant differences on several clinical features. Individuals in the NSSI group were more likely than individuals with BFRBs to report engaging in the behavior for social-affective reasons (i.e., to get out of doing something, or receive attention from others). Individuals in the NSSI group were also more likely to engage in the behavior to regulate tension and feelings of emptiness, and to experience relief during the act. In contrast, individuals in the BFRB groups were more likely to engage in the behavior automatically without reflective awareness, to reduce boredom, or to fix appearance. The NSSI group obtained significantly higher scores on questionnaires assessing stress, anxiety, depression, and harm avoidance. Overall, the results showed several notable differences between NSSI and BFRBs that are consistent with clinical literature and definitions of these problems in the DSM-5.

Trichotillomania associated with a 25-hydroxy vitamin D deficiency: A case report

Vitamin D deficiency has been correlated with non-scarring alopecia including alopecia areata or female pattern hair loss. It was theorized that hair loss secondary to vitamin D deficiency in patients susceptible to trichotillomania may exacerbate this obsessive-compulsive disorder. Though vitamin D deficiency is common, especially among patients suffering from neuropsychiatric disorders, its correlation with trichotillomania is not well reported. Two female patients suffering from trichotillomania defined by noticeable hair loss on the scalp through the Massachusetts General Hospital Hair Pulling Scale were treated to promote hair growth. Treatment included dietary supplementation with vitamin D3 1000 IU every day. It was found that in both patients treated with vitamin D3, marked improvements occurred over the span of 3 to 4 months. These included a reduction in obsessive compulsive disorder related hair loss as measured using the Massachusetts General Hospital Hair Pulling Scale, which correlated to their serum 25-hydroxyvitamin D levels. Experimental and clinical evidence is available to explain the underlying physiology and its probable relationship to trichotillomania's pathophysiology.

Bite the Stress Away? Nail Biting and Smoking Predict Maladaptive Stress Coping Strategies

Abstract. Psychological correlates of adult nail biting have received little empirical attention so far, despite its high prevalence and negative associations with physical and mental health. One possible correlate of nail biting is arousal modulation, which has also been linked to smoking (i.e., another oral behavior). Here, we link nail biting to an adaptive (i.e., Task-oriented) and two maladaptive stress-coping strategies (i.e., Emotion-oriented, Avoidance-oriented) as well as smoking while controlling for personality traits and socio-demographic characteristics. In all, 838 German-speaking adults ( Mage = 32.02, SD = 13.48; 431 women) completed measures of stress coping (CISS-SF), the Big Five personality traits (Mini-IPIP), and indicated nail biting and smoking behavior. In three theory-guided, hierarchical linear regressions we predicted each stress coping strategy by nail biting and smoking while controlling for personality and socio-demographic characteristics. Oral behaviors had differential effects on maladaptive stress coping strategies: The interaction between nail biting and smoking predicted Emotion-oriented coping, while smoking predicted Avoidance-oriented coping. Both behaviors were unrelated to adaptive, Task-oriented coping. In sum, our results show that nail biting and smoking are important predictors of maladaptive but not adaptive coping strategies, even when controlling for confounders.

Thermal sensors improve wrist-worn position tracking

Wearable devices provide a means of tracking hand position in relation to the head, but have mostly relied on wrist-worn inertial measurement unit sensors and proximity sensors, which are inadequate for identifying specific locations. This limits their utility for accurate and precise monitoring of behaviors or providing feedback to guide behaviors. A potential clinical application is monitoring body-focused repetitive behaviors (BFRBs), recurrent, injurious behaviors directed toward the body, such as nail biting and hair pulling, which are often misdiagnosed and undertreated. Here, we demonstrate that including thermal sensors achieves higher accuracy in position tracking when compared against inertial measurement unit and proximity sensor data alone. Our Tingle device distinguished between behaviors from six locations on the head across 39 adult participants, with high AUROC values (best was back of the head: median (1.0), median absolute deviation (0.0); worst was on the cheek: median (0.93), median absolute deviation (0.09)). This study presents preliminary evidence of the advantage of including thermal sensors for position tracking and the Tingle wearable device’s potential use in a wide variety of settings, including BFRB diagnosis and management.

The Role of the Cerebellum in Skin-Picking Disorder

Previous research indicated that the cerebellum is involved in psychopathologies with body-focused repetitive behaviors. The present study investigated whether patients with a diagnosis of skin-picking disorder (SPD) also show altered cerebellar structure and function. Structural as well as functional MRI data from 30 SPD patients and 31 controls were analyzed. The fMRI approach compared cerebellar activity and connectivity between the two groups during scratching and caressing of a small skin area on the arm. Relative to controls, SPD patients were characterized by reduced gray matter volumes in the left cerebellar lobules V and VI. During picking (relative to caressing), SPD patients displayed increased activation of the left crus I, which showed enhanced coupling with the left ventrolateral prefrontal cortex (VLPFC). This study provides the first evidence that SPD patients display structural as well as functional abnormalities in specific subregions of the cerebellum related to motor (V) and affective-cognitive functions (VI, crus I). The SPD-related altered cerebellar connectivity with an area implicated in affect control (VLPFC) fits nicely to the model of pathological skin picking as a maladaptive emotion regulation strategy.

The Beliefs in Trichotillomania Scale (BiTS): Factor analyses and preliminary validation

OBJECTIVES

The role of cognitions and beliefs in trichotillomania (TTM; hair pulling disorder) has been the subject of only limited investigation. This study aimed to develop and validate the Beliefs in TTM Scale (BiTS).

METHODS

A pool of 50 items based upon themes identified in previous research was administered online to 841 participants with and without self-reported problematic, non-cosmetic hair pulling behaviours.

RESULTS

Exploratory and confirmatory factor analyses conducted in randomly split-halves of the sample supported retention of 14 items comprising three factors: negative self-beliefs, low coping efficacy, and perfectionism.

CONCLUSIONS

The BiTS demonstrated satisfactory psychometric properties and all three subscales significantly correlated with greater hair pulling severity. Negative self-beliefs predicted hair pulling severity over and above mood symptoms, suggesting the importance of addressing self-construals in psychological treatments for TTM. Validation in a clinician diagnosed sample is required.

PRACTITIONER POINTS

Research supports cognitive therapies for treating trichotillomania (hair pulling disorder), although studies investigating the nature and role of cognitions and beliefs in this disorder have been lacking. This study developed and validated a self-report measure of three styles of beliefs most relevant to trichotillomania: negative self-beliefs, low coping efficacy, and perfectionism. Negative self-beliefs predicted the severity of trichotillomania symptoms over and above depression and anxiety, suggesting such cognitions may not necessarily be due to comorbidities. Future research should validate the new measure in a clinician diagnosed sample, and therapies for trichotillomania may be enhanced by targeting shame specifically.

Abnormal repetitive behaviors in zebrafish and their relevance to human brain disorders

Abnormal repetitive behaviors (ARBs) are a prominent symptom of numerous human brain disorders and are commonly seen in rodent models as well. While rodent studies of ARBs continue to dominate the field, mounting evidence suggests that zebrafish (Danio rerio) also display ARB-like phenotypes and may therefore be a novel model organism for ARB research. In addition to clear practical research advantages as a model species, zebrafish share high genetic and physiological homology to humans and rodents, including multiple ARB-related genes and robust behaviors relevant to ARB. Here, we discuss a wide spectrum of stereotypic repetitive behaviors in zebrafish, data on their genetic and pharmacological modulation, and the overall translational relevance of fish ARBs to modeling human brain disorders. Overall, the zebrafish is rapidly emerging as a new promising model to study ARBs and their underlying mechanisms.

Comprehensive behavioral treatment for an adult with sensory-based trichotillomania: An illustrative case study

Trichotillomania (TTM) is a poorly understood condition that causes significant impairment, but effective behavioral management strategies exist. The phenomenology of TTM is complex and requires an individualized treatment approach, and there are some important facets of TTM that have only recently been recognized. Specifically, contemporary research indicates that hair pulling is often performed to regulate aversive sensations and provide somatosensory reward. In this article, we describe the complex phenomenology of TTM, evidence-based treatment options, and illustrate a case of sensory-based TTM treated effectively with a comprehensive behavioral intervention.

A latent profile analysis of age of onset in pathological skin picking

BACKGROUND

Pathological Skin Picking (PSP) may begin at any age, but the most common age of onset is during adolescence. Age of onset is a potentially useful clinical marker to delineate subtypes of psychiatric disorders. The present study sought to examine empirically defined age of onset groups in adults with PSP and assess whether groups differed on clinical characteristics.

METHOD

Participants were 701 adult respondents to an internet survey, who endorsed recurrent skin picking with tissue damage and impairment. Latent profile analysis (LPA) was conducted to identify subtypes of PSP based on age of onset. Then subgroups were compared on demographic and clinical characteristics.

RESULTS

The best fitting LPA model was a two-class solution comprised of a large group with average age of onset in adolescence (n = 650; 92.9% of the sample; Mean age of onset = 13.6 years) and a small group with average onset in middle adulthood (n = 50; 7.1% of the sample; Mean age of onset = 42.8 years). Relative to the early onset group, the late onset group reported significantly less focused picking, less skin picking-related impairment, lower rates of co-occurring body-focused repetitive behaviors, and trends towards reduced family history of PSP. Individuals in the late onset group also reported increased rates of comorbid depression, anxiety and posttraumatic stress disorder, and were more likely to report that initial picking onset seemed related to or followed depression/anxiety and physical illness.

CONCLUSION

Findings suggest the presence of two distinct PSP age of onset groups: (1) an early onset group with average onset in adolescence, clinical characteristics suggestive of greater picking-related burden and familiality, and a profile more representative of the general PSP population; and (2) a late onset group with average onset in middle adulthood, increased co-occurring affective and trauma conditions, and initial onset associated with or following other mental health and physical problems. Future replication is needed to assess the validity and clinical utility of these subgroups.

Abnormal perceptual sensitivity in body-focused repetitive behaviors

OBJECTIVE

Several compulsive grooming habits such as hair pulling, skin picking, and nail biting are collectively known as body-focused repetitive behaviors (BFRBs). Although subclinical BFRBs are common and benign, more severe and damaging manifestations exist that are difficult to manage. Researchers have suggested that BFRBs are maintained by various cognitive, affective, and sensory contingencies. Although the involvement of cognitive and affective processes in BFRBs has been studied, there is a paucity of research on sensory processes.

METHODS

The current study tested whether adults with subclinical or clinical BFRBs would report abnormal patterns of sensory processing as compared to a healthy control sample.

RESULTS

Adults with clinical BFRBs (n = 26) reported increased sensory sensitivity as compared to persons with subclinical BFRBs (n = 48) and healthy individuals (n = 33). Elevations in sensation avoidance differentiated persons with clinical versus subclinical BFRBs. Sensation seeking patterns were not different between groups. Unexpectedly, BFRB severity was associated with lower registration of sensory stimuli, but this finding may be due to high psychiatric comorbidity rates in the BFRB groups.

CONCLUSIONS

These findings suggest that several sensory abnormalities may underlie BFRBs. Implications for the etiology and treatment of BFRBs are discussed.