An A-B-C model of habit disorders: hair-pulling, skin-picking, and other stereotypic conditions

Structural neuroimaging of skin-picking disorder

BACKGROUND

Skin-picking disorder (SPD) is conceptualized as an obsessive-compulsive and related disorder (OCRD). Patients with SPD excessively manipulate their skin, which leads to skin lesions, psychological distress, and functional impairment. The neuroanatomical facets of this disorder are still poorly understood.

METHODS

A total of 220 participants (123 patients with a primary diagnosis of SPD and 97 healthy controls; mean age = 30 years, 80% female) were recruited for a voxel-based morphometry (VBM) study. VBM data were compared between patients and controls, and between three SPD subgroups, each characterized by a distinct age of symptom onset (before puberty, during puberty, adulthood).

RESULTS

Relative to the healthy comparison group, patients with SPD had significantly less grey matter volume (GMV) in regions of interest (ROIs: insula, orbitofrontal cortex, pallidum, cerebellum, supramarginal gyrus) and in the frontal pole and occipital regions (whole-brain findings). Early onset of symptoms (before puberty) was associated with elevated levels of focused skin-picking, in addition to less GMV in specific ROIs (insula, orbitofrontal cortex) as well as in paracingulate/ superior temporal regions (whole-brain findings).

CONCLUSIONS

SPD-related reductions in GMV were identified in brain regions involved in interoception, emotion regulation, and motor control. This partially aligns with findings for OCD. The detection of different age-of-onset groups based on clinical as well as morphometric data points to the heterogeneity of the disorder and warrants further investigation.

Clinical Characteristics, Sleep, and Temperament in Infants and Young Children with Problematic Hair Pulling and Skin Picking

Background

This study examined clinical characteristics of problematic hair pulling (HP) and skin picking (SP) in infants and young children and their association with self-soothing, sleep, and temperament.

Methods

An internet survey of parents/caregivers of 0-5-year-olds (n = 384 with data analyzed, of whom 26 experienced HP, 62 experienced SP, and 302 were controls free of HP and SP) assessed demographics and medical history, HP and SP characteristics, contextual factors, self-soothing, sleep patterns, and temperament. Participants were recruited through both HP and SP advocacy and support webpages and general webpages (e.g., parenting groups). Descriptive statistics, chi-square tests of independence, independent samples t-test clinically characterized HP, SP, and control groups. Logistic regression and one-way analysis of covariance controlled for sex and age in analyses.

Results

HP and SP rates were 6.1% (n = 26) and 14.5% (n = 62), respectively. SP presented in 23.1% of children with HP, and HP presented in 9.7% of children with SP. Mean HP and SP onset occurred at 12.2 (SD = 11.2) and 24.1 (SD = 15.8) months, respectively. Contextual factors, including boredom, upset, and awake-in-bed were common in HP and SP. Common caregiver responses included distracting the child, moving the hand away, and telling the child to stop. Few caregivers sought professional help for the child. Children with HP engaged in more hair twirling than controls, and children with SP engaged in more nail biting than controls. Children with HP, but not SP, had more sleep disturbance than controls. In terms of temperament, children with HP displayed sensitivity to stimuli, children with SP exhibited low persistence, and both HP and SP groups displayed serious, observant mood relative to controls.

Conclusions

Findings expand clinical understanding of HP and SP in children aged 0-5 and provide targets (contextual factors, sleep, sensory sensitivity, persistence, and mood) for behavioral interventions. Low rates of treatment seeking highlight the need for expansion of clinical guidelines for HP and SP in this age range.

Characteristics of 262 adults with skin picking disorder

INTRODUCTION

Skin picking disorder (also known as excoriation disorder or dermatillomania) is a common mental health disorder currently classified as an obsessive-compulsive and related condition. Despite being first described in the 1800s, very little is known about its phenomenology and clinical presentation. Most information about this disorder to date is based on online surveys rather than in-person assessments.

METHODS

Clinical and demographic data were collected from individuals with skin-picking disorder taking part in research studies, using in-person assessments comprising validated instruments. Descriptive information was presented as to the nature of skin picking disorder.

RESULTS

The sample comprised 262 individuals, mean age 32.5 years, being 87% female. The peak age of onset of symptoms was 12.9 years, and most affected individuals (>90%) had symptom onset before age of 20 years. Typically, individuals reported picking from multiple body sites (most common was the face), and the most frequent triggers were stress and the 'feel' (i.e. texture) of the skin. Comorbidities were common, including trichotillomania, depression, generalized anxiety disorder, and impulsive/compulsive disorders (especially attention-deficit hyperactivity disorder and obsessive-compulsive disorder). The majority of people with the disorder (87.1%) had never received treatment. Of those who had received treatment in the past, 87% reported that they found the treatment helpful for their symptoms.

DISCUSSION

This study sheds new light on the clinical presentation and phenomenology of skin picking disorder. Results highlight the need for further research into its clinical presentation, longitudinal course, and treatment approaches.

Pharmacotherapy for trichotillomania

BACKGROUND

Trichotillomania (TTM; hair-pulling disorder) is a prevalent and disabling disorder characterised by recurrent hair-pulling. Here we update a previous Cochrane Review on the effects of medication for TTM.

OBJECTIVES

To assess the effects of medication for trichotillomania (TTM) in adults, children and adolescents compared with placebo or other medication.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, PsycINFO, eleven other bibliographic databases, trial registries and grey literature sources (to 26 November 2020). We checked reference lists and contacted subject experts.

SELECTION CRITERIA

We selected randomised controlled trials of medication versus placebo or other medication for TTM in adults, children and adolescents.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

Twelve studies were included. We identified 10 studies in adults (286 participants) with a mean sample size of 29 participants per trial; one study in children and adolescents (39 participants); and, one study in adults and adolescents (22 participants: 18 adults and 4 adolescents). All studies were single-centre, outpatient trials. Eleven studies compared medication and placebo (334 participants); one study compared two medications (13 participants). Studies were 5 to 13 weeks duration. We undertook meta-analysis only for opioid antagonists as other comparisons contained a single study, or reported insufficient data. Antioxidants versus placebo in adults There was little to no difference in treatment response between antioxidant (35.7%) and placebo groups (28.6%) after six weeks, based on a single trial of silymarin (risk ratio (RR) 2.25, 95% confidence interval (CI) 0.84 to 5.99; 36 participants; low-certainty evidence). We could not calculate differences in number of dropouts as there were no events in either group (18 participants; low-certainty evidence). Antioxidants versus placebo in adolescents There was little to no difference in treatment response between antioxidant (50%) and placebo groups (25%) after six weeks, based on a single trial of silymarin (RR 2.00, 95% CI 0.28 to 14.20; 8 participants; low-certainty evidence). We could not calculate differences in number of dropouts as there were no events in either group (8 participants; low-certainty evidence). Antipsychotics versus placebo in adults There may be greater treatment response in the antipsychotic group (85%) compared to the placebo group (17%) after 12 weeks, based on a single trial of olanzapine (RR 5.08, 95% CI 1.4 to 18.37; 25 participants; low-certainty evidence). We could not calculate differences in number of dropouts as there were no events in either group (25 participants; low-certainty evidence). Cell signal transducers versus placebo in adults There was little to no difference in treatment response between cell signal transducer (42.1%) and placebo groups (31.6%) after 10 weeks, based on a single trial of inositol (RR 1.33, 95% CI 0.57 to 3.11; 38 participants; low-certainty evidence). We could not calculate differences in number of dropouts as there were no events in either group (38 participants; low-certainty evidence). Glutamate modulators versus placebo in adults There is probably greater treatment response in the glutamate modulator group (56%) compared to the placebo group (16%) after 12 weeks, based on a single trial of N-acetylcysteine (RR 3.5, 95% CI 1.34 to 9.17; 50 participants; moderate-certainty evidence). We could not calculate differences in number of dropouts as there were no events in either group (50 participants; low-certainty evidence). Glutamate modulators versus placebo in children and adolescents There was little to no difference in treatment response between the glutamate modulator (25%) and placebo groups (21.1%) in children and adolescents, based on a single trial of N-acetylcysteine (RR 1.19, 95% CI 0.37 to 3.77; 39 participants; low-certainty evidence). There was little to no difference in dropouts due to adverse events between glutamate modulator (5%) and placebo (0%) groups, based on a single trial (RR 2.86, 95% CI 0.12 to 66.11; 39 participants; low-certainty evidence). Opioid antagonists versus placebo in adults There may be little to no difference in treatment response between opioid antagonist (37.5%) and placebo groups (25%) after six to eight weeks, based on two studies of naltrexone, but the evidence is very uncertain (RR 2.14, 95% CI 0.25 to 18.17; 2 studies, 68 participants; very low-certainty evidence). No data were available regarding dropouts due to adverse events. Selective serotonin reuptake inhibitors (SSRIs) versus placebo in adults There were no data available for treatment response to SSRIs. There was little to no difference in dropouts due to adverse events in the SSRI group (5.1%) compared to the placebo group (0%) after 6 to 12 weeks, based on two trials of fluoxetine (RR 3.00, 95% CI 0.33 to 27.62; 2 studies, 78 participants; low-certainty evidence). Tricyclic antidepressants (TCAs) with predominantly serotonin reuptake inhibitor (SRI) actions versus placebo in adults There may be greater treatment response in the TCAs with predominantly SRI actions group (40%) compared to the placebo group (0%) after nine weeks, but the evidence is very uncertain, based on a single trial of clomipramine (RR 5.73, 95% CI 0.36 to 90.83; 16 participants; very low-certainty evidence). There may be increased dropouts due to adverse events in the TCAs with predominantly SRI actions group (30%) compared to the placebo group (0%), but the evidence is very uncertain (RR 4.45, 95% CI 0.27 to 73.81; 16 participants; very low-certainty evidence). TCAs with predominantly SRI actions versus other TCAs in adults There may be greater treatment response in the TCAs with predominantly SRI actions group compared to the other TCAs group after five weeks, based on a single trial comparing clomipramine to desipramine (mean difference (MD) -4.00, 95% CI -6.13 to -1.87; 26 participants; low-certainty evidence). We could not calculate differences in number of dropouts as there were no events in either group (26 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

There was insufficient evidence from meta-analysis to confirm or refute the efficacy of any agent or class of medication for the treatment of TTM in adults, children or adolescents. Preliminary evidence suggests there may be beneficial treatment effects for N-acetylcysteine, clomipramine and olanzapine in adults based on four trials, albeit with relatively small sample sizes.

Evaluating the role of Approach-Avoidance Training on action-tendencies in individuals with skin-picking disorder: A preliminary randomized experiment

BACKGROUND AND AIMS

Pathological skin-picking (PSP) or excoriation disorder is a destructive behavior that affects 1-2% of the general population. The purpose of this pilot study was to evaluate the effect of a computerized behavior modification task on action-tendencies (i.e., approach or avoidance) in adults with PSP. We aimed to modify these action-tendencies by having participants with PSP complete the Approach-Avoidance Training (AAT) task, using a joystick to simulate an approach (=pull) or avoidance (=push) response.

METHOD

Forty-five participants diagnosed with PSP were randomized to one of three training conditions: (1) Avoidance Training (AvT; n = 15), (2) Approach Training (ApT; n = 15), or (3) Placebo Training (PT; n = 15). We hypothesized that after training, those in the AvT would have the greatest reduction in behavioral approach (i.e., their overall reaction time [RT] to approach pictures of irregular skin stimuli).

RESULTS

Results of the pre-training assessment task revealed a positive correlation between behavioral approach to irregular skin stimuli and skin-picking severity as assessed by the Skin Picking Scale-Revised (SPS-R). After training, a lower behavioral approach and urges to pick were found in the AvT and PT groups, while those in the ApT reported higher behavioral approach and urges to pick. At two-week follow-up, no significant changes on the SPS-R were reported between groups.

DISCUSSION

Our preliminary data suggest that the AAT is a promising avenue of research to develop as a cognitive intervention to address an excessive behavioral approach tendency that characterizes skin-picking problems.

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.

Skin and Psychosomatics - Psychodermatology today

Modern psychodermatology relies on the bio-psycho-social disease model in psychosomatics, according to which biological, psychological and social factors (on various levels, from molecules to the biosphere) play a major role in the disease pathogenesis through complex, non-linear interactions over the entire disease course. It is nowadays experimentally proven that "emotions get into the skin". Recent research shows close anatomical, physiological and functional connections between skin and nervous system, already known to be ontogenetically related. These connections are reflected in many skin diseases where psychological and somatic etiological factors are closely intertwined. A holistic approach by the physician should do justice to this interdependence; biological, psychological and social factors should be adequately taken into account when taking anamnesis, making a diagnosis and choosing a therapy. The "visibility" of the skin organ bestows dermatology a special position among the various other clinical subjects, and renders a holistic, psychosomatic approach to the patient that is particularly important. The life course belongs also to modern psychodermatological approaches. Based on the modern psychodermatology concept, other corresponding sub-areas such as psychogastroenterology, psychocardiology etc. have emerged. After the theoretical part of this article, some selected skin diseases are discussed in more detail from the psychosomatic point of view.

Drug Treatment of Trichotillomania (Hair-Pulling Disorder), Excoriation (Skin-picking) Disorder, and Nail-biting (Onychophagia)

BACKGROUND

Trichotillomania (TTM), excoriation (or skin-picking) disorder and some severe forms of onychophagia are classified under obsessive-compulsive and related disorders. There are different interacting neurotransmitter systems involved in the pathophysiology of impulse-control disorders, implicating noradrenaline, serotonin, dopamine, opioid peptides and glutamate, hence investigators focused on drugs able to act on these transmitters. Our aim was to critically review the efficacy of the drugs employed in impulse-control disorders.

METHODS

We searched for controlled drug trials to treat TTM, excoriation, and/or nail-biting six databases (PubMed, Cochrane, Scopus, CINAHL, PsycINFO/PsycARTICLES, and Web of Science), using the search strategy: (trichotillomania OR "excoriation disorder" OR "face picking" OR "skin picking" OR "hair pulling" OR onychophagia OR "nail-biting") AND drug treatment on 12 March 2018 for all databases. We followed in our method of identifying relevant literature the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

RESULTS

SSRIs and clomipramine are considered first-line in TTM. In addition, family members of TTM patients are often affected by obsessive-compulsive spectrum disorders. Other drugs used in the treatment of TTM are lamotrigine, olanzapine, N-Acetylcysteine, inositol, and naltrexone.

CONCLUSION

The treatment of TTM, excoriation disorder and nail-biting is still rather disappointing. Conjectures made from preclinical studies and the relative pathophysiological hypotheses found poor confirmations at a clinical level. There is a need for further studies and the integration of pharmacological and psychotherapeutic. Our results point to the need of integrating personalised medicine principles in the treatment of these patients.

The Terrestrial Carnivorous Plant Utricularia reniformis Sheds Light on Environmental and Life-Form Genome Plasticity

Utricularia belongs to Lentibulariaceae, a widespread family of carnivorous plants that possess ultra-small and highly dynamic nuclear genomes. It has been shown that the Lentibulariaceae genomes have been shaped by transposable elements expansion and loss, and multiple rounds of whole-genome duplications (WGD), making the family a platform for evolutionary and comparative genomics studies. To explore the evolution of Utricularia, we estimated the chromosome number and genome size, as well as sequenced the terrestrial bladderwort Utricularia reniformis (2n = 40, 1C = 317.1-Mpb). Here, we report a high quality 304 Mb draft genome, with a scaffold NG50 of 466-Kb, a BUSCO completeness of 87.8%, and 42,582 predicted genes. Compared to the smaller and aquatic U. gibba genome (101 Mb) that has a 32% repetitive sequence, the U. reniformis genome is highly repetitive (56%). The structural differences between the two genomes are the result of distinct fractionation and rearrangements after WGD, and massive proliferation of LTR-retrotransposons. Moreover, GO enrichment analyses suggest an ongoing gene birth-death-innovation process occurring among the tandem duplicated genes, shaping the evolution of carnivory-associated functions. We also identified unique patterns of developmentally related genes that support the terrestrial life-form and body plan of U. reniformis. Collectively, our results provided additional insights into the evolution of the plastic and specialized Lentibulariaceae genomes.

White matter volume alterations in hair-pulling disorder (trichotillomania)

Trichotillomania (TTM) is a disorder characterized by repetitive hair-pulling resulting in hair loss. Key processes affected in TTM comprise affective, cognitive, and motor functions. Emerging evidence suggests that brain matter aberrations in fronto-striatal and fronto-limbic brain networks and the cerebellum may characterize the pathophysiology of TTM. The aim of the present voxel-based morphometry (VBM) study was to evaluate whole brain grey and white matter volume alteration in TTM and its correlation with hair-pulling severity. High-resolution magnetic resonance imaging (3 T) data were acquired from 29 TTM patients and 28 age-matched healthy controls (CTRLs). All TTM participants completed the Massachusetts General Hospital Hair-Pulling Scale (MGH-HPS) to assess illness/pulling severity. Using whole-brain VBM, between-group differences in regional brain volumes were measured. Additionally, within the TTM group, the relationship between MGH-HPS scores, illness duration and brain volumes were examined. All data were corrected for multiple comparisons using family-wise error (FWE) correction at p < 0.05. Patients with TTM showed larger white matter volumes in the parahippocampal gyrus and cerebellum compared to CTRLs. Estimated white matter volumes showed no significant association with illness duration or MGH-HPS total scores. No significant between-group differences were found for grey matter volumes. Our observations suggest regional alterations in cortico-limbic and cerebellar white matter in patients with TTM, which may underlie deficits in cognitive and affective processing. Such volumetric white matter changes may precipitate impaired cortico-cerebellar communication leading to a reduced ability to control hair pulling behavior.

Disentangling Reward Processing in Trichotillomania: 'Wanting' and 'Liking' Hair Pulling Have Distinct Clinical Correlates

Trichotillomania (TTM; hair-pulling disorder) is characterized by an irresistible urge or desire to pull out one's own hair, and a sense of pleasure when hair is pulled out. Evidence from translational neuroscience has shown that 'wanting' (motivation to seek a reward) and 'liking' (enjoyment when reward is received) are each mediated by overlapping but distinct neural circuitry, and that 'wanting' contributes to addictive/compulsive behaviors more so than 'liking'. In the present study, we developed the Hair Pulling Reward Scale (HPRS), a self-report measure that consists of two subscales designed to assess (a) cue-triggered urges and appetitive motivation to pull hair (i.e., putative correlates of 'wanting'), and (b) momentary pleasure and gratification during pulling episodes (i.e., putative correlates of 'liking'). We administered the HPRS to 259 individuals with TTM and examined its psychometric properties. Confirmatory factor analysis supported a two-factor model reflecting correlated Wanting and Liking scales. Consistent with predictions, Wanting, much more than Liking, had robust correlations with TTM severity, impulsiveness, difficulties in emotion regulation, psychiatric symptoms, and sleep dysfunction. The results suggest that the HPRS is a psychometrically sound instrument that can be used as a symptom-level measure of reward processing in TTM.

Habit Reversal Therapy in Obsessive Compulsive Related Disorders: A Systematic Review of the Evidence and CONSORT Evaluation of Randomized Controlled Trials

Background: Habit Reversal Therapy (HRT) has long been used in the treatment of Tourette Syndrome and Tic Disorders. It has more recently been used to treat Trichotillomania and skin picking behaviors, both considered as Obsessive Compulsive Related Disorders (OCRD). Objectives: This literature review sought to establish and quality assess the existing randomized controlled trial evidence supporting the use of HRT in the DSM-5 family of OCRDs. Search Methods: EMBASE, PsycINFO, PubMed, and Cochrane databases were searched for key terms relating to each OCRD (as classified in the DSM-5), and HRT. Selection Criteria: Titles and abstracts were screened, and any literature matching pre-specified criteria were then selected to be reviewed further. Of these, 8 Randomized Controlled Trials (RCT) relating to Trichotillomania, and 2 RCTs relating to Excoriation Disorder, were extracted and reviewed against the 2010 Consolidating Standards of Reporting Trials (CONSORT) statement. Results: The review identified 10 RCTs of HRT, but these were limited to patients with a primary diagnosis of Trichotillomania or "excoriation behavior," only. There were some reports of the use of HRT in Tourette Syndrome or Tic Disorder with secondary OCD, but the OCD symptoms were not reliably reported on. Conclusion: There is a gap in the current literature regarding the use of HRT in the DSM-5 OCRDs. In those RCTs that have been reported, the quality of study methodology was questionable as evaluated by CONSORT criteria. The implications of these findings are discussed, and suggestions are made for future research.

Online Porn Addiction: What We Know and What We Don't-A Systematic Review

In the last few years, there has been a wave of articles related to behavioral addictions; some of them have a focus on online pornography addiction. However, despite all efforts, we are still unable to profile when engaging in this behavior becomes pathological. Common problems include: sample bias, the search for diagnostic instrumentals, opposing approximations to the matter, and the fact that this entity may be encompassed inside a greater pathology (i.e., sex addiction) that may present itself with very diverse symptomatology. Behavioral addictions form a largely unexplored field of study, and usually exhibit a problematic consumption model: loss of control, impairment, and risky use. Hypersexual disorder fits this model and may be composed of several sexual behaviors, like problematic use of online pornography (POPU). Online pornography use is on the rise, with a potential for addiction considering the "triple A" influence (accessibility, affordability, anonymity). This problematic use might have adverse effects in sexual development and sexual functioning, especially among the young population. We aim to gather existing knowledge on problematic online pornography use as a pathological entity. Here we try to summarize what we know about this entity and outline some areas worthy of further research.

An fMRI Pilot Study of Cognitive Flexibility in Trichotillomania

Trichotillomania is a relatively common psychiatric condition, although its neurobiological basis is unknown. Abnormalities of flexible responding have been implicated in the pathophysiology of obsessive-compulsive disorder and thus may be relevant in trichotillomania. The purpose of this study was to probe reversal learning and attentional set-shifting in trichotillomania. Twelve adults with trichotillomania and 13 matched healthy control subjects undertook a functional MRI task of cognitive flexibility. Group-level activation maps for extradimensional and reversal switches were independently parcellated into discrete regions of interest using a custom watershed algorithm. Activation magnitudes were extracted from each region of interest and study subject and compared at the group level. Reversal events evoked the expected patterns of insula and parietal regions and activity in the frontal dorsal cortex extending anterior to the frontal poles, whereas extradimensional shifts evoked the expected frontal dorsolateral and parietal pattern of activity. Trichotillomania was associated with significantly increased right middle frontal and reduced right occipital cortex activation during reversal and set-shifting. Elevated frontal activation coupled with reduced activation in more posterior brain regions was identified. These pilot data suggest potentially important neural dysfunction associated with trichotillomania.

Systematic Review of Published Primary Studies of Neuropsychology and Neuroimaging in Trichotillomania

OBJECTIVES

Existing models of trichotillomania (TTM; hair pulling disorder) rely heavily on a biological predisposition or biological pathogenesis of the disorder, but fail to capture the specific neuropsychological mechanisms involved. The present systematic review aims to scope existing neuropsychological studies of TTM to explore gaps in current models.

METHODS

A systematic literature search was conducted to detect all published primary studies using neuropsychological and neuroimaging measures in a cohort of individuals experiencing TTM. Studies addressing neuropsychological function were divided into domains. Findings from imaging studies were considered within brain regions and across methodology.

RESULTS

Thirty studies with a combined 591 participants with TTM, 372 healthy controls and 225 participants in other types of control group were included. Sixteen studies investigated neuropsychological parameters, and 14 studies pursued neuroimaging technologies. Available studies that used neuropsychological assessments and reported a statistically significant difference between those with TTM and controls ranged in effect size from 0.25 to 1.58. All domains except verbal ability and visual ability reported a deficit. In neuroimaging studies, several structural and functional brain changes were reported that might be of significance to TTM. Only tentative conclusions can be made due to the use of multiple methodologies across studies, a major limitation to meaningful interpretations.

CONCLUSIONS

Positive neuropsychological and neuroimaging results require replication, preferably with multi-site studies using standardized methodology. Increased standardized testing and analyses across the literature, as a whole, would improve the utility and interpretability of knowledge in this field. (JINS, 2018, 24, 188-205).

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.

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.

Pathological grooming: Evidence for a single factor behind trichotillomania, skin picking and nail biting

Although trichotillomania (TTM), skin picking (SP), and nail biting (NB) have been receiving growing scientific attention, the question as to whether these disorders can be regarded as separate entities or they are different manifestations of the same underlying tendency is unclear. Data were collected online in a community survey, yielding a sample of 2705 participants (66% women, mean age: 29.1, SD: 8.6). Hierarchical factor analysis was used to identify a common latent factor and the multiple indicators and multiple causes (MIMIC) modelling was applied to test the predictive effect of borderline personality disorder symptoms, impulsivity, distress and self-esteem on pathological grooming. Pearson correlation coefficients between TTM, SP and NB were between 0.13 and 0.29 (p < 0.01). The model yielded an excellent fit to the data (CFI = 0.992, TLI = 0.991, χ2 = 696.65, p < 0.001, df = 222, RMSEA = 0.030, Cfit of RMSEA = 1.000), supporting the existence of a latent factor. The MIMIC model indicated an adequate fit (CFI = 0.993, TLI = 0.992, χ2 = 655.8, p < 0.001, df = 307, RMSEA = 0.25, CI: 0.022-0.028, pclose = 1.000). TTM, SP and NB each were loaded significantly on the latent factor, indicating the presence of a general grooming factor. Impulsivity, psychiatric distress and contingent self-esteem had significant predictive effects, whereas borderline personality disorder had a nonsignificant predictive effect on the latent factor. We found evidence that the category of pathological grooming is meaningful and encompasses three symptom manifestations: trichotillomania, skin picking and nail biting. This latent underlying factor is not better explained by indicators of psychopathology, which supports the notion that the urge to self-groom, rather than general psychiatric distress, impulsivity, self-esteem or borderline symptomatology, is what drives individual grooming behaviours.

Human compulsivity: A perspective from evolutionary medicine

Biological explanations address not only proximal mechanisms (for example, the underlying neurobiology of obsessive-compulsive disorder), but also distal mechanisms (that is, a consideration of how particular neurobiological mechanisms evolved). Evolutionary medicine has emphasized a series of explanations for vulnerability to disease, including constraints, mismatch, and tradeoffs. The current paper will consider compulsive symptoms in obsessive-compulsive and related disorders and behavioral addictions from this evolutionary perspective. It will argue that while obsessive-compulsive disorder (OCD) is typically best conceptualized as a dysfunction, it is theoretically and clinically valuable to understand some symptoms of obsessive-compulsive and related disorders in terms of useful defenses. The symptoms of behavioral addictions can also be conceptualized in evolutionary terms (for example, mismatch), which in turn provides a sound foundation for approaching assessment and intervention.

Behavioural addiction-A rising tide?

The term 'addiction' was traditionally used in relation to centrally active substances, such as cocaine, alcohol, or nicotine. Addiction is not a unitary construct but rather incorporates a number of features, such as repetitive engagement in behaviours that are rewarding (at least initially), loss of control (spiralling engagement over time), persistence despite untoward functional consequences, and physical dependence (evidenced by withdrawal symptoms when intake of the substance diminishes). It has been suggested that certain psychiatric disorders characterized by maladaptive, repetitive behaviours share parallels with substance addiction and therefore represent 'behavioural addictions'. This perspective has influenced the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), which now has a category 'Substance Related and Addictive Disorders', including gambling disorder. Could other disorders characterised by repetitive behaviours, besides gambling disorder, also be considered 'addictions'? Potential examples include kleptomania, compulsive sexual behaviour, 'Internet addiction', trichotillomania (hair pulling disorder), and skin-picking disorder. This paper seeks to define what is meant by 'behavioural addiction', and critically considers the evidence for and against this conceptualisation in respect of the above conditions, from perspectives of aetiology, phenomenology, co-morbidity, neurobiology, and treatment. Research in this area has important implications for future diagnostic classification systems, neurobiological models, and novel treatment directions.

Review of available studies of the neurobiology and pharmacotherapeutic management of trichotillomania

Trichotillomania (TTM) is a psychiatric disorder characterized by an irresistible urge to pull out one's hair. Currently there are no FDA approved treatments for TTM, which makes it difficult for clinicians to select an appropriate therapeutic plan. The clinical studies that have been performed do not provide sufficient or consistent evidence regarding which drug classes should be administered. Unfortunately, most of the available data consist of case reports and clinical trials with limited sample size. This review provides an overview of currently available clinical literature that targets TTM. A summary of clinical trials as well as case reports is provided. The most common rating scales used for clinical assessment are also reviewed. The etiology of TTM remains unclear. Studies that examine various neuroanatomical, neurobiologic, as well as genetic factors associated with TTM are thoroughly discussed in this review. It is evident that clear understanding of TTM is crucial to provide better recognition, assessment, and treatment to patients of this disorder. Finally, despite research efforts for establishing pharmacological options for treatment, it is clear that new targets are warranted in order to ensure a clinically supported effective pharmacological approach to treat TTM.

Abnormal brain activation in excoriation (skin-picking) disorder: evidence from an executive planning fMRI study

BACKGROUND

Excoriation (skin-picking) disorder (SPD) is a relatively common psychiatric condition whose neurobiological basis is unknown.

AIMS

To probe the function of fronto-striatal circuitry in SPD.

METHOD

Eighteen participants with SPD and 15 matched healthy controls undertook an executive planning task (Tower of London) during functional magnetic resonance imaging (fMRI). Activation during planning was compared between groups using region of interest and whole-brain permutation cluster approaches.

RESULTS

The SPD group exhibited significant functional underactivation in a cluster encompassing bilateral dorsal striatum (maximal in right caudate), bilateral anterior cingulate and right medial frontal regions. These abnormalities were, for the most part, outside the dorsal planning network typically activated by executive planning tasks.

CONCLUSIONS

Abnormalities of neural regions involved in habit formation, action monitoring and inhibition appear involved in the pathophysiology of SPD. Implications exist for understanding the basis of excessive grooming and the relationship of SPD with putative obsessive-compulsive spectrum disorders.

Excoriation (skin-picking) disorder in adults: a cross-cultural survey of Israeli Jewish and Arab samples

OBJECTIVE

We sought to estimate the lifetime prevalence of Excoriation (Skin-Picking) Disorder (SPD) in the Israeli adult population as a whole and compare SPD prevalence in the Jewish and Arab communities. We also explored demographic, medical and psychological correlates of SPD diagnosis.

METHODS

Questionnaires and scales screening for SPD, and assessing the severity of perceived stress, depression, obsessive-compulsive disorder (OCD), body dysmorphic disorder (BDD), alcohol use, illicit drug use, and medical disorders were completed in a sample of 2145 adults attending medical settings.

RESULTS

The lifetime prevalence of SPD was 5.4% in the total sample; it did not differ between genders or within Jewish and Arab subsamples. Severity of depression (p<0.001), OCD (p<0.001) and perceived stress (p=<0.001) were greater in the SPD positive sample. Similarly, diagnoses of BDD (p=0.02) and generalized anxiety (p=0.03) were significantly more common in the SPD-positive respondents. Alcohol use and illicit substance use were significantly more common among SPD positive respondents in the total sample (both p's=0.01) and the Jewish subsample (p=0.03 and p=0.02, respectively). Hypothyroidism was more prevalent in the SPD-positive Jewish subsample (p=0.02). In the total sample, diabetes mellitus was more common in women than in men (p=0.04).

CONCLUSION

Lifetime SPD appears to be relatively common in Israeli adults and associated with other mental disorders. Differences in the self-reported medical and psychiatric comorbidities between the Jewish and Arab subsamples suggest the possibility of cross-cultural variation in the correlates of this disorder.

Trichotillomania in Children

BACKGROUND

Trichotillomania is an often underdiagnosed condition. Little is known about trichotillomania in childhood. We aimed to analyze the characteristics of children with trichotillomania to increase information on this condition.

METHODS

A retrospective study of an electronic database was performed in a tertiary children's hospital. Information from patients with trichotillomania was systematically classified under the categories 'who', 'what', 'when', 'where', 'why', and 'how'.

RESULTS

A total of 33 patients had a diagnosis of trichotillomania (28 females, 5 males; peak age between 3 and 4 years). Scalp involvement was most common and nail biting was observed in 5 patients. Only 51.5% of patients had parents who noticed their child's hairpulling. Hair on or under the bed was the most common clue suggesting that hairpulling occurred. Triggering factors identified in 16 children included physical appearance, family-related issues, school-related issues, and concurrent illness. The noninvasive hair pull test was negative in all children. There was a high non-follow-up rate, and treatment outcomes varied.

CONCLUSION

A set of 6 specific questions, based on the '5Ws and 1H' principle, facilitates the gathering of important information on children with unexplained nonscarring hair loss and helps clinicians be cognizant of possible outcomes of trichotillomania. This will be especially useful to clinicians who are not familiar with this elusive condition.

Impaired response inhibition and excess cortical thickness as candidate endophenotypes for trichotillomania

Trichotillomania is characterized by repetitive pulling out of one's own hair. Impaired response inhibition has been identified in patients with trichotillomania, along with gray matter density changes in distributed neural regions including frontal cortex. The objective of this study was to evaluate impaired response inhibition and abnormal cortical morphology as candidate endophenotypes for the disorder. Subjects with trichotillomania (N = 12), unaffected first-degree relatives of these patients (N = 10), and healthy controls (N = 14), completed the Stop Signal Task (SST), a measure of response inhibition, and structural magnetic resonance imaging scans. Group differences in SST performance and cortical thickness were explored using permutation testing. Groups differed significantly in response inhibition, with patients demonstrating impaired performance versus controls, and relatives occupying an intermediate position. Permutation cluster analysis revealed significant excesses of cortical thickness in patients and their relatives compared to controls, in right inferior/middle frontal gyri (Brodmann Area, BA 47 & 11), right lingual gyrus (BA 18), left superior temporal cortex (BA 21), and left precuneus (BA 7). No significant differences emerged between groups for striatum or cerebellar volumes. Impaired response inhibition and an excess of cortical thickness in neural regions germane to inhibitory control, and action monitoring, represent vulnerability markers for trichotillomania. Future work should explore genetic and environmental associations with these biological markers.

Stereotyped movement disorder in ICD-11

According to current proposals for ICD-11, stereotyped movement disorder will be classified in the grouping of neurodevelopmental disorders, with a qualifier to indicate whether self-injury is present, similar to the classification of stereotypic movement disorder in DSM-5. At the same time, the WHO ICD-11 Working Group on the Classification of Obsessive-Compulsive and Related Disorders has proposed a grouping of body-focused repetitive behavior disorders within the obsessive-compulsive and related disorders (OCRD) cluster to include trichotillomania and skin-picking disorder. DSM-5 has taken a slightly different approach: trichotillomania and excoriation (skin picking) disorder are included in the OCRD grouping, while body-focused repetitive behavior disorder is listed under other specified forms of OCRD. DSM-5 also includes a separate category of nonsuicidal self-injury in the section on "conditions for further study." There are a number of unresolved nosological questions regarding the relationships among stereotyped movement disorder, body-focused repetitive behavior disorders, and nonsuicidal self-injury. In this article, we attempt to provide preliminary answers to some of these questions as they relate to the ICD-11 classification of mental and behavioral disorders.

Excoriation (skin picking) disorder in Israeli University students: prevalence and associated mental health correlates

OBJECTIVE

The purpose of the study was to examine the prevalence of excoriation (skin picking) disorder (SPD) and associated physical and mental health correlates in a sample of Israeli university students.

METHODS

Five thousand Israeli students were given questionnaires screening for SPD, depression, obsessive-compulsive disorder, body dysmorphic disorder and disruptive, impulse control and conduct disorders. A total of 2176 participants (43.6%) responded and were included in the analysis. Mean age was 25.1 ± 4.8 (range 17-60) years, and 64.3% were female.

RESULTS

The proportion of students who were screened positive for SPD was 3.03%, with a nearly equal gender distribution (3.0% in females and 3.1% in males). There was a trend toward significantly higher rates of psychiatric problems such as generalized anxiety, compulsive sexual behavior and eating disorders in these students. Within the group of students screening positive for SPD, alcohol intake was higher in male students, while female students perceived themselves as less attractive. No association was found between depression and SPD. A high prevalence rate of skin picking was found within first-degree family members of the participants screening positive for SPD.

CONCLUSIONS

Clinicians and public health officials within university settings should screen for SPD as it is common and associated with psychosocial dysfunction.

Animal models of obsessive-compulsive spectrum disorders

Obsessive-compulsive disorder (OCD) and related conditions (trichotillomania, pathological skin-picking, pathological nail-biting) are common and disabling. Current treatment approaches fail to help a significant proportion of patients. Multiple tiers of evidence link these conditions with underlying dysregulation of particular cortico-subcortical circuitry and monoamine systems, which represent targets for treatment. Animal models designed to capture aspects of these conditions are critical for several reasons. First, they help in furthering our understanding of neuroanatomical and neurochemical underpinnings of the obsessive-compulsive (OC) spectrum. Second, they help to account for the brain mechanisms by which existing treatments (pharmacotherapy, psychotherapy, deep brain stimulation) exert their beneficial effects on patients. Third, they inform the search for novel treatments. This article provides a critique of key animal models for selected OC spectrum disorders, beginning with initial work relating to anxiety, but moving on to recent developments in domains of genetic, pharmacological, cognitive, and ethological models. We find that there is a burgeoning literature in these areas with important ramifications, which are considered, along with salient future lines of research.

Skin picking disorder in university students: health correlates and gender differences

OBJECTIVE

This study sought to examine the prevalence of skin picking disorder (SPD) in a university sample and assess associated physical and mental health correlates.

METHODS

A 54-item anonymous, voluntary survey was distributed via random email generation to a sample of 6000 university students. Current psychological and physical status was assessed, along with academic performance. Positive screens for SPD were determined based upon individuals meeting full proposed DSM-V criteria.

RESULTS

A total of 1916 participants (31.9%; mean age 22.7 ± 5.1; 58.1% female) responded and were included in the analysis. The overall prevalence of SPD was 4.2% (females=5.8%; males=2.0%). SPD was associated with significantly higher lifetime rates of affective, anxiety, eating, substance use and impulse control disorders. Men with SPD had significantly higher BMI ratings and perceived themselves as significantly less attractive to others while women had significantly higher depressive symptoms.

CONCLUSION

SPD is common in both genders and is associated with significant mental and physical health detriments, including higher levels of stress, more psychiatric comorbidity and poorer perceived health. Academic institutions, clinicians and public health officials should be aware of the multimodal presentation of SPD and screen for it in primary care and dermatologic settings.

Life threatening self starvation; a case report

Background

Obsessive compulsive disorders are a complex group that can have a variety of manifestations. Many authors now describe an obsessive compulsive spectrum disorder where many other specific diagnostic entities such as trichotillomania, tic disorders and body dysmorphic disorder are considered to be related and linked disorders.

Case presentation

We report a case of a twenty two year old Sri Lankan male who presented with life threatening self starvation due to severe obsessive compulsive disorder. The diagnosis was not considered till late due to the atypical presentation of the patient. While his symptoms bordered on a delusional psychosis, a decision was made to treat him as for obsessive compulsive disorder with behavioural therapy which was successful in the end.

Conclusions

In analysis of a patient with severe anorexia, the psychological causes should not be forgotten. In fact, if the feeding pattern of the patient was observed at the beginning, unnecessary investigating and life threatening worsening of the condition could have been avoided.

A cognitive comparison of pathological skin picking and trichotillomania

OBJECTIVE

Pathological Skin Picking (PSP) and Trichotillomania (TTM) share overlapping comorbidity and phenomenology. The extent to which these disorders share a common cognitive phenotype, however, has yet to be examined. This study sought to compare inhibitory control processes in individuals with PSP or TTM.

METHODS

Thirty-one subjects with PSP (mean age 31.2 ± 12.5 years; 93.5% female), 39 subjects with TTM (mean age 35.9 ± 10.7 years; 87.2% female), and 33 matched controls (mean age 31.9 ± 9.9 years; 72.7% female) undertook cognitive assessments using the Stop-Signal Task (assessing response impulsivity) and the Intra-dimensional/Extra-dimensional (ID/ED) Set Shift task (assessing cognitive flexibility). Groups were matched for age, gender, race/ethnicity, and education.

RESULTS

PSP was associated with significantly impaired stop-signal reaction times but intact ID/ED cognitive flexibility compared to controls. TTM occupied an intermediate position in terms of stop-signal reaction times between controls and PSP but did not differ significantly from either group on the ID/ED Set Shift Task.

CONCLUSION

These results replicate the finding of impaired inhibitory control in PSP but suggest TTM may be heterogeneous with respect to such impairment. Future work should explore possible subgroups in TTM and whether cognitive variables are predictive of treatment outcomes.

A Randomized Controlled Trial of a Novel Self-Help Technique for Impulse Control Disorders

Nail-biting is currently classified as an impulse control disorder not otherwise specified. Although seldom targeted as a primary symptom, nail-biting is often associated with somatic complications and decreased quality of life. The present study assessed the effectiveness of an innovative self-help technique, titled decoupling (DC). DC aims at attenuating pathological nail-biting by performing motor sequences that decouple and rearrange the behavioral elements involved in the habit. A total of 72 participants with excessive nail-biting were recruited via specialized self-help forums and were randomized to either DC or progressive muscle relaxation (PMR) groups after baseline assessment. Four weeks later, participants underwent a similar assessment as before and were asked to rate the effectiveness of the intervention. The primary outcome parameter was the Massachusetts General Hospital Scale (MGH) adapted. Relative to the PMR group, the DC group showed significant progress in withstanding the urge to bite their nails. Furthermore, they appraised the appearance of their nails as considerably less compromised at the end of the treatment relative to participants undergoing PMR. At statistical trend level, the DC group showed a significantly greater decline on the adapted MGH relative to PMR. Despite methodological limitations, the present study asserts that the effectiveness of DC, previously shown for trichotillomania, extends to nail-biting.

Quality of life and clinical severity in pathological skin picking and trichotillomania

Pathological skin picking (PSP) and trichotillomania (TTM) are disorders characterized by distress and impaired functioning. This study sought to compare quality of life for individuals with PSP or TTM. PSP or TTM subjects completed the quality of life inventory and valid and reliable measures of clinical severity. Analyses included group comparisons of PSP, TTM and healthy controls, and within-group comparisons. 59 subjects with PSP (mean age 33.4±12.8; 88.1% female), 70 with TTM (mean age 34.8±12.0; 88.6% female), and 25 healthy controls (mean age 31.3±10.1; 80% female) were included. PSP subjects reported more psychosocial impairment compared to TTM subjects (p=0.013). Both PSP and TTM subjects had lower quality of life scores compared to healthy controls. Quality of life was not associated with symptom severity. Larger studies should examine further the impact PSP and TTM have on quality of life as well as the role quality of life itself plays in the severity and duration of illness.

Effects of acute modafinil on cognition in trichotillomania

RATIONALE

Individuals with trichotillomania often report significant difficulty resisting the urges and drive to pull hair.

OBJECTIVES

The aim of this study is to examine whether modafinil improves motor inhibitory control, and other cognitive functions, in trichotillomania.

METHODS

Eighteen subjects with trichotillomania (mean age 33.4 ± 12.8 years; 78% female) received a single dose of modafinil (200 mg) and placebo in a crossover double-blind design. Neurocognitive performance was assessed using the stop-signal, pattern recognition, rapid visual information processing and Tower of London tasks.

RESULTS

No effects of modafinil on cognition approached statistical significance on the test measures examined (all p > 0.10).

CONCLUSIONS

These results suggest that modafinil may not be useful for targeting impulse dyscontrol in trichotillomania. However, it remains possible that relatively small effects of modafinil on cognition could exert larger downstream effects on overt behaviour. Further trials using modafinil and other pro-cognitive agents are warranted.

Pilot trial of dialectical behavior therapy-enhanced habit reversal for trichotillomania

BACKGROUND

Not all hair pullers improve acutely with cognitive-behavioral treatment (CBT) and few maintain their gains over time.

METHODS

We conducted an open clinical trial of a new treatment that addresses affectively triggered pulling and emphasizes relapse prevention in addition to standard CBT approaches. Ten female participants satisfying DSM-IV criteria for trichotillomania (TTM) at two study sites received Dialectical Behavior Therapy (DBT)-enhanced CBT consisting of 11 weekly sessions and 4 maintenance sessions over the following 3 months. Independent assessors rated hair pulling impairment and global improvement at several study time points. Participants completed self-report measures of hair pulling severity and emotion regulation.

RESULTS

Significant improvement in hair pulling severity and emotion regulation, as well as hair pulling impairment and anxiety and depressive symptoms, occurred during acute treatment and were maintained during the subsequent 3 months. Significant correlations were reported between changes in emotion regulation and hair pulling severity during both the acute treatment and maintenance phases.

CONCLUSIONS

This study offers preliminary evidence for the efficacy of DBT-enhanced CBT for TTM and suggests the importance of addressing emotion regulation during TTM treatment.

A double-blind, placebo-controlled trial of lamotrigine for pathological skin picking: treatment efficacy and neurocognitive predictors of response

Although a relatively common behavior, treatment data for pathological skin picking (PSP) are limited. The current study sought to examine the efficacy and tolerability of lamotrigine in adults with PSP and to examine neurocognitive predictors of treatment response. Thirty-two subjects (29 female subjects [90.6%]; mean age, 32.8 +/- 13.3 years) with PSP were treated in a 12-week randomized, double-blind, placebo-controlled trial of lamotrigine as monotherapy. Baseline cognitive assessment comprised the stop signal and intradimensional/extradimensional set shift tasks. Lamotrigine dosing ranged from 12.5 to 300 mg/d. The primary outcome measure was picking symptoms measured by the Yale-Brown Obsessive Compulsive scale Modified for Neurotic Excoriation. Subjects also were assessed with measures of psychosocial functioning. No significant overall differences were noted between lamotrigine and placebo on the primary or secondary end points. Seven subjects assigned to lamotrigine (43.8%) were considered responders (defined as >or=35% n the Yale-Brown Obsessive Compulsive scale Modified for Neurotic Excoriation) compared with 5 (31.3%) assigned to placebo. Those who ultimately responded to lamotrigine exhibited impaired cognitive flexibility (extradimensional shifting) at baseline compared with lamotrigine nonresponders. These findings suggest that, although safe and well tolerated, lamotrigine treatment may not be efficacious in patients with PSP as a whole, compared with placebo. However, these neurocognitive data suggest that lamotrigine may be valuable in a subset of patients who exhibit relatively impaired cognitive flexibility.

A clinical comparison of pathologic skin picking and obsessive-compulsive disorder

BACKGROUND

It has been hypothesized that pathologic skin picking (PSP) shares many of the same biological and phenomenological characteristics as obsessive-compulsive disorder (OCD). This study sought to examine the clinical similarities between PSP and OCD.

METHOD

Demographic and clinical characteristic data were examined in a treatment-seeking sample of 53 PSP (mean age, 34.2 +/- 13.1 years; 86.8% female) and 51 OCD (mean age, 36.5 +/- 11.7 years; 35.3% female) subjects. Psychiatric comorbidity and family history data were also obtained.

RESULTS

The PSP subjects were more likely to be female (P < .001), report higher rates of co-occurring compulsive nail biting (P < .001), and have a first-degree relative with a grooming disorder (P < .001). The OCD subjects spent significantly more time on their thoughts and behaviors (P < .001) and were more likely to have co-occurring body dysmorphic disorder (P = .001).

CONCLUSION

Although PSP and OCD share some clinical similarities, important differences exist and cast doubt on the conceptualization of PSP as simply a variant of OCD.

Volitional disorders: a proposal for DSM-V

In the DSM-IV-TR, specific impulse control disorders not elsewhere classified (ICD) have been designated following four principles: (1) through the addition of an adjective that emphasizes the aberrant character of an otherwise normal behaviour (e.g., pathological gambling); (2) by means of metaphors (such as in intermittent explosive disorder); (3) according to the presumably quintessential nature of their main signs and symptoms, such as impulsive (e.g., impulse control disorders not elsewhere classified), compulsive (e.g., compulsive shopping), or addictive (e.g., internet addiction); or (4) using Greek suffix mania (e.g., kleptomania, pyromania, and trichotillomania). Given this flagrant inconsistency, we argue that time has come to adopt a less arbitrary way of describing these disorders, at least until it becomes clearer whether they are really impulsive, compulsive or addictive or if the preoccupation with this distinction is valid. In keeping with DSM's emphasis on descriptive phenomenology rather than on unsupported theory, a less biased terminology is in order. Therefore, we would like to suggest: (1) the substitution of the term ICD by the more neutral expression 'volitional disorders not elsewhere classified'; (2) the use of the classical Greek suffix mania, already present in some DSM-IV-TR ICDs, as the main naming principle to be adopted in the DSM-V; and (3) the creation of compulsive, impulsive, and mixed subtypes of the 'volitional disorders not elsewhere classified', since they are beginning to be validated by treatment trials.

Probing compulsive and impulsive behaviors, from animal models to endophenotypes: a narrative review

Failures in cortical control of fronto-striatal neural circuits may underpin impulsive and compulsive acts. In this narrative review, we explore these behaviors from the perspective of neural processes and consider how these behaviors and neural processes contribute to mental disorders such as obsessive-compulsive disorder (OCD), obsessive-compulsive personality disorder, and impulse-control disorders such as trichotillomania and pathological gambling. We present findings from a broad range of data, comprising translational and human endophenotypes research and clinical treatment trials, focussing on the parallel, functionally segregated, cortico-striatal neural projections, from orbitofrontal cortex (OFC) to medial striatum (caudate nucleus), proposed to drive compulsive activity, and from the anterior cingulate/ventromedial prefrontal cortex to the ventral striatum (nucleus accumbens shell), proposed to drive impulsive activity, and the interaction between them. We suggest that impulsivity and compulsivity each seem to be multidimensional. Impulsive or compulsive behaviors are mediated by overlapping as well as distinct neural substrates. Trichotillomania may stand apart as a disorder of motor-impulse control, whereas pathological gambling involves abnormal ventral reward circuitry that identifies it more closely with substance addiction. OCD shows motor impulsivity and compulsivity, probably mediated through disruption of OFC-caudate circuitry, as well as other frontal, cingulate, and parietal connections. Serotonin and dopamine interact across these circuits to modulate aspects of both impulsive and compulsive responding and as yet unidentified brain-based systems may also have important functions. Targeted application of neurocognitive tasks, receptor-specific neurochemical probes, and brain systems neuroimaging techniques have potential for future research in this field.

Motor inhibition and cognitive flexibility in pathologic skin picking

BACKGROUND

Individuals with pathologic skin picking (PSP) often report significant difficulty resisting the urges and drive to engage in picking behavior. Studies have shown significant inhibitory deficiencies (i.e. increased impulsivity) in subjects with other putative obsessive-compulsive spectrum disorders, such as trichotillomania, using objective tests. This study sought to assess motor inhibitory control and aspects of cognitive flexibility in a sample of individuals with PSP.

METHOD

Twenty subjects with PSP (mean age 33.1+/-14.3 years; 85% female) and 20 healthy controls (mean age 31.6+/-9.1 years; 85% female) underwent cognitive assessments using the Stop-signal and Intra-dimensional/Extra-dimensional (ID/ED) set-shift tasks. Groups were matched for age, gender, and education.

RESULTS

PSP was associated with significantly impaired stop-signal reaction times but intact ID/ED cognitive flexibility compared to controls. Measures of disease severity in the PSP subjects did not covary significantly with stop-signal performance.

CONCLUSION

The finding of impaired inhibitory control but intact set-shift cognitive flexibility draws remarkable parallels with findings in trichotillomania but differs from obsessive compulsive disorder. These findings have important implications for understanding potential neurobiological dysfunction in PSP, how the disorder should be classified, and suggest new potential treatment directions.

The epidemiology of obsessive-compulsive disorder in the National Comorbidity Survey Replication

Despite significant advances in the study of obsessive-compulsive disorder (OCD), important questions remain about the disorder's public health significance, appropriate diagnostic classification, and clinical heterogeneity. These issues were explored using data from the National Comorbidity Survey Replication, a nationally representative survey of US adults. A subsample of 2073 respondents was assessed for lifetime Diagnostic and Statistical Manual of Mental Disorders, 4th edn (DSM-IV) OCD. More than one quarter of respondents reported experiencing obsessions or compulsions at some time in their lives. While conditional probability of OCD was strongly associated with the number of obsessions and compulsions reported, only small proportions of respondents met full DSM-IV criteria for lifetime (2.3%) or 12-month (1.2%) OCD. OCD is associated with substantial comorbidity, not only with anxiety and mood disorders but also with impulse-control and substance use disorders. Severity of OCD, assessed by an adapted version of the Yale-Brown Obsessive Compulsive Scale, is associated with poor insight, high comorbidity, high role impairment, and high probability of seeking treatment. The high prevalence of subthreshold OCD symptoms may help explain past inconsistencies in prevalence estimates across surveys and suggests that the public health burden of OCD may be greater than its low prevalence implies. Evidence of a preponderance of early onset cases in men, high comorbidity with a wide range of disorders, and reliable associations between disorder severity and key outcomes may have implications for how OCD is classified in DSM-V.

Update on pathological skin picking

Pathological skin picking (PSP) is a disabling disorder characterized by repetitive picking of the skin that causes tissue damage. Estimated to affect 2% to 5.4% of the population, PSP is currently listed as an impulse control disorder not otherwise specified. However, the repetitive and compulsive behaviors seen in PSP are phenomenologically and clinically similar to the behaviors seen in obsessive-compulsive disorder and other body-focused repetitive behaviors, such as trichotillomania and pathological nail biting. Animal neuroimaging research in related disorders such as obsessive-compulsive disorder and trichotillomania provides useful information for understanding PSP. Recent cognitive testing of individuals with PSP demonstrated impaired inhibitory control; these findings may assist in the proper characterization of PSP and aid in the development of effective treatment options. Although the disorder is common, appropriate treatments for PSP are limited. Pharmacotherapeutic and certain cognitive-behavioral interventions have demonstrated promise in treating this disorder and need to be explored further.