A preliminary analysis of the phenomenology of skin-picking in Prader-Willi syndrome

Prolapsed Rectum and Risk Factors in Prader-Willi Syndrome: A Case-Based Review

A 14-year-old male adolescent patient with Prader-Willi syndrome (PWS) with maternal disomy 15 was reported with rectal prolapse as only the second patient in the literature. With predisposing risk factors present for rectal damage and prolapse in this syndrome, the incidence must be higher and therefore underreported. These risk factors include skin and rectal picking, self-stimulation, altered pain sensation, decreased muscle mass, strength and physical activity with hypotonia, and gastrointestinal (GI) disturbances. Pertinent literature was reviewed and analyzed that focused on clinical features and behavior seen in PWS as underrecognized risk factors for developing rectal damage and prolapse. An illustrative case is presented as the second patient reported with PWS and a prolapsed rectum. A discussion of predisposing behavioral and clinical risk factors is presented including for self-stimulation, rectal picking, chronic constipation, decreased gut motility, reduced water intake, and a restricted diet. Although a paucity of cases do exist, physical, behavioral, and GI findings common in PWS may contribute to rectal prolapse requiring better awareness and proactive surveillance, management, and treatment protocols for patients affected with this rare obesity-related genetic disorder.

Dermatillomania: Strategies for Developing Protective Biomaterials/Cloth

Dermatillomania or skin picking disorder (SPD) is a chronic, recurrent, and treatment resistant neuropsychiatric disorder with an underestimated prevalence that has a concerning negative impact on an individual’s health and quality of life. The current treatment strategies focus on behavioral and pharmacological therapies that are not very effective. Thus, the primary objective of this review is to provide an introduction to SPD and discuss its current treatment strategies as well as to propose biomaterial-based physical barrier strategies as a supporting or alternative treatment. To this end, searches were conducted within the PubMed database and Google Scholar, and the results obtained were organized and presented as per the following categories: prevalence, etiology, consequences, diagnostic criteria, and treatment strategies. Furthermore, special attention was provided to alternative treatment strategies and biomaterial-based physical treatment strategies. A total of six products with the potential to be applied as physical barrier strategies in supporting SPD treatment were shortlisted and discussed. The results indicated that SPD is a complex, underestimated, and underemphasized neuropsychiatric disorder that needs heightened attention, especially with regard to its treatment and care. Moreover, the high synergistic potential of biomaterials and nanosystems in this area remains to be explored. Certain strategies that are already being utilized for wound healing can also be further exploited, particularly as far as the prevention of infections is concerned.

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.

A profile of mental health and behaviour in Prader-Willi syndrome

BACKGROUND

Prader-Willi syndrome (PWS) is a neurogenetic syndrome with an associated behavioural phenotype and a high incidence of behaviours of concern and psychiatric co-morbidity. These associated behaviours and co-morbidities are not well addressed by existing interventions, and they impact significantly on affected individuals and their caregivers.

METHODS

We undertook a national survey of the needs of individuals with PWS and their families in Ireland. In this paper, we report on the parent/caregiver-reported mental health, behavioural and access to services.

RESULTS

Over 50% of individuals with PWS in this survey had at least one reported psychiatric diagnosis, the most common diagnosis was anxiety. The most commonly reported behaviours in children were skin picking, repetitive questioning, difficulty transitioning and non-compliance. The same four behaviours were reported by caregivers as being the most commonly occurring in adolescents and adults in addition to food-seeking behaviours. Increased needs for mental health services were also reported by caregivers. Individuals with PWS had an average wait of 22 months for an appointment with a psychologist and 4 months for an appointment with a psychiatrist.

CONCLUSION

This study highlighted high levels of psychiatric co-morbidities and behavioural concerns in individuals with PWS in Ireland. The findings of this study suggest that there is an urgent need to provide specialist psychiatric and behavioural interventions to manage complex mental health and behavioural needs to better support individuals with PWS and reduce caregiver burden.

Rectal Picking Masquerading as Inflammatory Bowel Disease in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is a genetic syndrome in which individuals have multisystem medical challenges. Gastroenterological difficulties in the syndrome include decreased vomiting, constipation, delayed gastric emptying, delayed colonic transit, dysphagia, increased choking, and increased risk of gastric dilation and rupture. In addition, self-injurious behavior such as rectal picking may be present and severe enough to lead to rectal ulceration and bleeding. Many patients have extensive gastroenterological workup and treatment before their ultimate diagnosis of severe rectal picking. We describe 4 new cases of rectal picking in individuals with PWS leading to rectal bleeding and ulceration as well as a review of the literature of prior cases of severe rectal picking in PWS and potential treatment options. It is important to recognize these cases early in order to prevent unnecessary treatments and implement appropriate behavioral interventions.

A mindfulness-based intervention for self-management of verbal and physical aggression by adolescents with Prader-Willi syndrome

PURPOSE

There is a dearth of clinical and research literature on the treatment of maladaptive behaviors in adolescents with Prader-Willi syndrome (PWS). The purpose of this study was to evaluate the effectiveness of a mindfulness-based intervention, Meditation on the Soles of the Feet (SoF), to facilitate self-management of verbal and physical aggression.

METHOD

We utilized a multiple-baseline design across participants to test the intervention with three adolescents diagnosed with PWS.

RESULTS

Relative to baseline, verbal aggression decreased to minimal levels following mindfulness-based practice and physical aggression was nearly eliminated. Intervention effects were maintained at 12-month follow-up. Quantitative analytics confirmed statistically significant outcomes.

CONCLUSIONS

The SoF mindfulness intervention was effective in reducing verbal and physical aggression in three adolescents with PWS. Future research should test the SoF intervention with this clinical population in a larger clinical trial, and the SoF intervention may be applicable to other pediatric populations.

Psychiatric disorders in a cohort of individuals with Prader-Willi syndrome

BACKGROUND

Psychiatric manifestations in Prader-Willi Syndrome (PWS) are common and often are the most debilitating problem in these individuals. We present an epidemiological nation-wide survey of psychiatric diagnoses in the PWS population, based on full-range psychiatric interviews.

METHODS

We studied the distribution of psychiatric diagnoses (as opposed to a symptom-based approach) in the Israel national cohort of adolescents and adults with PWS. There was a total of 53 (32 males) ages 12 years and older. All individuals and their caretakers were interviewed using standardized psychiatric questionnaires. Demographic and clinical variables, Clinical Global Impression (CGI) score, IQ, severity of hyperphagia and quality of life (QOL) were also assessed and correlations with NPD (number of psychiatric diagnoses) calculated.

RESULTS

An overwhelming majority (89%) of the study participants had at least one psychiatric diagnosis. The most common were disruptive behavior disorders (DBD) (68%), obsessive compulsive disorder (OCD) (45%) and skin picking (35%). Individuals with DBD were at increased risk for OCD and skin picking. Psychotic disorders were found in 11%. NPD had a significant negative influence on QOL. There was no correlation between NPD and BMI, IQ, hyperphagia severity, hormonal profile or genetic subtypes.

CONCLUSIONS

Psychiatric diagnoses are very frequent in PWS and strongly influence QOL. Furthermore, characterizing the profile of psychiatric comorbidity in PWS is crucial for planning effective interventions. Precise behavioral phenotyping in PWS in combination with a well-defined genetic etiology may aid biological research linking biological correlates to behavior.

Anomalous basal ganglia connectivity and obsessive-compulsive behaviour in patients with Prader Willi syndrome

BACKGROUND

Prader Willi syndrome is a genetic disorder with a behavioural expression characterized by the presence of obsessive-compulsive phenomena ranging from elaborate obsessive eating behaviour to repetitive skin picking. Obsessive-compulsive disorder (OCD) has been recently associated with abnormal functional coupling between the frontal cortex and basal ganglia. We have tested the potential association of functional connectivity anomalies in basal ganglia circuits with obsessive-compulsive behaviour in patients with Prader Willi syndrome.

METHODS

We analyzed resting-state functional MRI in adult patients and healthy controls. Whole-brain functional connectivity maps were generated for the dorsal and ventral aspects of the caudate nucleus and putamen. A selected obsessive-compulsive behaviour assessment included typical OCD compulsions, self picking and obsessive eating behaviour.

RESULTS

We included 24 adults with Prader Willi syndrome and 29 controls in our study. Patients with Prader Willi syndrome showed abnormal functional connectivity between the prefrontal cortex and basal ganglia and within subcortical structures that correlated with the presence and severity of obsessive-compulsive behaviours. In addition, abnormally heightened functional connectivity was identified in the primary sensorimotor cortex-putamen loop, which was strongly associated with self picking. Finally, obsessive eating behaviour correlated with abnormal functional connectivity both within the basal ganglia loops and between the striatum and the hypothalamus and the amygdala.

LIMITATIONS

Limitations of the study include the difficulty in evaluating the nature of content of obsessions in patients with Prader Willi Syndrome and the risk of excessive head motion artifact on brain imaging.

CONCLUSION

Patients with Prader Willi syndrome showed broad functional connectivity anomalies combining prefrontal loop alterations characteristic of OCD with 1) enhanced coupling in the primary sensorimotor loop that correlated with the most impulsive aspects of the behaviour and 2) reduced coupling of the ventral striatum with limbic structures for basic internal homeostasis that correlated with the obsession to eat.

Psychotropic treatments in Prader-Willi syndrome: a critical review of published literature

Prader-Willi syndrome (PWS) is a rare genetic syndrome. The phenotype includes moderate to intellectual disability, dysmorphia, obesity, and behavioral disturbances (e.g., hetero and self-injurious behaviors, hyperphagia, psychosis). Psychotropic medications are widely prescribed in PWS for symptomatic control. We conducted a systematic review of published literature to examine psychotropic medications used in PWS. MEDLINE was searched to identify articles published between January 1967 and December 2014 using key words related to pharmacological treatments and PWS. Articles with original data were included based on a standardized four-step selection process. The identification of studies led to 241 records. All selected articles were evaluated for case descriptions (PWS and behavioral signs) and treatment (type, titration, efficiency, and side effects). Overall, 102 patients were included in these studies. Treatment involved risperidone (three reports, n = 11 patients), fluoxetine (five/n = 6), naltrexone (two/n = 2), topiramate (two/n = 16), fluvoxamine (one/n = 1), mazindol (one/n = 2), N-acetyl cysteine (one/n = 35), rimonabant (one/n = 15), and fenfluramine (one/n = 15).

CONCLUSION

We identified promising treatment effects with topiramate for self-injury and impulsive/aggressive behaviors, risperidone for psychotic symptoms associated with uniparental disomy (UPD), and N-acetyl cysteine for skin picking. The pharmacological approach of behavioral impairment in PWS has been poorly investigated to date. Further randomized controlled studies are warranted.

WHAT IS KNOWN

Behavioral disturbances in Prader-Willi syndrome including aggressive reactions, skin picking, and hyperphagia might be very difficult to manage. Antipsychotic drugs are widely prescribed, but weight gain and increased appetite are their major side effects.

WHAT IS NEW

Topiramate might be efficient for self-injury and impulsive/aggressive behaviors, N-acetyl cysteine is apromising treatment for skin picking and Antidepressants are indicated for OCD symptoms. Risperidone is indicated in case of psychotic symptoms mainly associated with uniparental disomy.

Multidisciplinary assessment and treatment of self-injurious behavior in autism spectrum disorder and intellectual disability: integration of psychological and biological theory and approach

The objective of this review is to consider the psychological (largely behavioral) and biological [neurochemical, medical (including genetic), and pharmacological] theories and approaches that contribute to current thinking about the etiology and treatment of self-injurious behavior (SIB) in individuals with autism spectrum disorder and/or intellectual disability. Algorithms for the assessment and treatment of SIB in this context, respectively, from a multidisciplinary, integrative perspective are proposed and challenges and opportunities that exist in clinical and research settings are discussed.

N-acetyl cysteine in the treatment of obsessive compulsive and related disorders: a systematic review

OBJECTIVE

Obsessive compulsive and related disorders are a collection of debilitating psychiatric disorders in which the role of glutamate dysfunction in the underpinning neurobiology is becoming well established. N-acetyl cysteine (NAC) is a glutamate modulator with promising therapeutic effect. This paper presents a systematic review of clinical trials and case reports exploring the use of NAC for these disorders. A further objective was to detail the methodology of current clinical trials being conducted in the area.

METHODS

PubMed, Web of Science and Cochrane Library Database were searched for human clinical trials or case reports investigating NAC in the treatment of obsessive compulsive disorder (OCD) or obsessive compulsive related disorders. Researchers with known involvement in NAC studies were contacted for any unpublished data.

RESULTS

Four clinical trials and five case reports/series were identified. Study durations were commonly 12-weeks, using 2,400-3,000 mg/day of NAC. Overall, NAC demonstrates activity in reducing the severity of symptoms, with a good tolerability profile and minimal adverse effects. Currently there are three ongoing randomized controlled trials using NAC for OCD (two adults and one pediatric), and one for excoriation.

CONCLUSIONS

Encouraging results have been demonstrated from the few pilot studies that have been conducted. These results are detailed, in addition to a discussion of future potential research.

Psychiatric disorders in children with Prader-Willi syndrome-Results of a 2-year longitudinal study

Psychiatric disorders such as psychosis are highly prevalent in adults with Prader-Willi syndrome (PWS). However, knowledge about the presence and progression of psychiatric disorders in children with PWS is very limited. Sixty-one children with PWS aged 7-17 years were tested using the Diagnostic Interview Schedule for Children (DISC) and Compulsive Behaviour Checklist (CBC), and 38/61 were retested after 2 years. Prevalence of psychiatric disorders and the association with age, gender, genetic subtype, and total IQ were assessed. In addition, occurrence and characteristics of compulsions were determined. Prior to the study, two boys were known with psychotic symptoms and treated with antipsychotics. At baseline, none scored positive for psychotic disorder. During the follow-up, only one boy with known psychotic symptoms required a dose adjustment of his antipsychotic medication. After 2 years, none of the children had a psychotic disorder according to the DISC. Oppositional defiant disorder (ODD) was the most common diagnosis and present in 20% of children with PWS, and this was not associated with age (β = -0.081, P = 0.546), gender (β = 0.013, P = 0.923), genetic subtype (β = -0.073, P = 0.584), or total IQ (β = -0.150, P = 0.267). The most common compulsions were hoarding and fixed hygiene sequences. In our large group of 61 children with PWS, the majority had no psychotic disorder and no progression was found during 2-year follow-up. ODD was present in 20% of children. No changes in the prevalence of psychiatric disorders were found during the 2-year follow-up study and genetic subtype was not related to psychosis, depression, or ODD.

Experimental functional analysis of severe skin-picking behavior in Prader-Willi syndrome

Skin picking is an extremely distressing and treatment resistant behavior commonly shown by individuals with Prader-Willi syndrome (PWS). However, with the exception of a limited number of published single-case and survey studies, little is known about the environmental determinants of skin picking in this population. In this study, functional analyses were conducted with thirteen individuals with PWS, aged 6-23 years, who engaged in severe skin-picking behavior. In addition to the conditions typically employed in a functional analysis (i.e., alone, attention, play, demand), we included an ignore condition to examine potential effects of stimulus control by the presence of an adult. Twelve participants engaged in skin picking during the functional analysis, with the highest levels occurring in the alone and ignore conditions for eight participants, suggesting that skin picking in these participants was maintained by automatic reinforcement. For the remaining four participants, an undifferentiated pattern of low-rate skin picking was observed across conditions. These data confirm previous studies indicating that skin picking in PWS may be maintained most often by automatically produced sensory consequences. There were no associations between demographic characteristics of the participants (e.g., sex, age, IQ or BMI) and levels of skin picking observed in the functional analysis. Additional investigations are needed to identify the nature of the sensory consequences produced during episodes of skin picking in PWS. Behavioral interventions designed to extinguish or compete with the potential sensory consequences arising from skin picking in PWS are also warranted.

An open-label pilot study of N-acetylcysteine for skin-picking in Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by an abnormality on the long arm of chromosome 15 (q11-q13) that results in a host of behavioral characteristics including excessive interest in food, skin picking, difficulty with a change in routine, and obsessive and compulsive behaviors. Skin-picking can result in serious and potentially life-threatening infections. Recent evidence suggests that the excitatory neurotransmitter glutamate is dysregulated in obsessive-compulsive behaviors, and modulation of the glutaminergic pathway may decrease compulsive behaviors, such as recurrent hair pulling or skin-picking behaviors. N-acetylcysteine (NAC), a derivative of the amino acid cysteine, is thought to act either via modulation of NMDA glutamate receptors or by increasing glutathione in pilot studies. Thirty-five individuals with confirmed PWS (ages 5-39 years, 23 females/12 males) and skin-picking behavior for more than 1 year were treated with N-acetylcysteine (Pharma-NAC®) at a dose of 450-1,200 mg/day. Skin-picking symptoms and open lesions were assessed after 12 weeks of treatment by counting and measuring lesions before and after the medication. All 35 individuals had improvement in skin-picking behaviors. Ten (29%) individuals (six males and four females) did not have complete resolution of skin-picking behavior, but had significant reduction in the number of active lesions. Longer-term, placebo-controlled trials are needed to further assess the potential benefit of this treatment.

Impaired theory of mind and symptoms of Autism Spectrum Disorder in children with Prader-Willi syndrome

In order to evaluate the social cognitive functioning in children with Prader-Willi syndrome (PWS), Theory of Mind (ToM) and symptoms of Autism Spectrum Disorder were evaluated. Sixty-six children with PWS aged 7-17 years were tested using the Theory of Mind test-R and the Diagnostic Interview for Social Communication disorders. We tested the correlation between Total ToM Standard Deviation Score (Total ToM SDS) and genetic subtype of paternal deletion or maternal uniparental disomy, and total IQ, verbal IQ and performal IQ. Prevalence and symptoms of Autism Spectrum Disorder were assessed. Median (interquartile range) of total ToM SDS of those aged 7-17 years was -3.84 (-5.73, -1.57). Their Total ToM SDS correlated with total IQ (β=0.662, p<0.001, adj.R(2)=0.407), in particular with verbal IQ (β=0.502, p=0.001, adj.R(2)=0.409), but not with performal IQ (β=0.241, p>0.05, adj.R(2)=0.259). No difference in Total ToM SDS was found between children with deletion and maternal uniparental disomy (β=-0.143, p>0.05, adj.R(2)=-0.016). Compared to the reference group of healthy children aged 7-12 years, children with PWS in the same age group had a median ToM developmental delay of 4 (3-5) years. One third of children with PWS scored positive for Autism Spectrum Disorder. Most prominent aberrations in Autism Spectrum Disorder were focused on maladaptive behavior. Our findings demonstrate a markedly reduced level of social cognitive functioning, which has consequences for the approach of children with PWS, i.e. adjustment to the child's level of social cognitive functioning.

An analysis of the topography, severity, potential sources of reinforcement, and treatments utilized for skin picking in Prader-Willi syndrome

We examined the topography, severity, potential sources of reinforcement, and treatments utilized for skin-picking behavior shown by individuals with Prader-Willi syndrome (PWS). The parents of 55 individuals with PWS, aged 6-25 years, were interviewed about their child's skin-picking behavior using the Self-Injury Trauma Scale (SIT; Iwata, Pace, Kissel, Nau, & Farber, 1990) and the Functional Analysis Screening Tool (FAST; Iwata, DeLeon, & Roscoe, 2013). Results showed that skin picking in PWS occurred on the extremities (i.e., arms, legs, hands, and feet) for 75% of cases and resulted in bodily injury for 83.7% cases. Skin picking posed a high risk to the individual concerned in 41.8% of cases. Automatic sensory stimulation was identified as a potential source of reinforcement in the majority of cases (52.7%) followed by access to social attention or preferred items (36.4%). Treatments utilized by parents were primarily behavioral strategies (56.3%) followed by basic first aid (54.5%). There were no differences in the topography, severity or potential source of reinforcement between those with the deletion (DEL) subtype and those with the uniparental disomy (UPD) subtype. Taken together, these data indicate that skin picking shown by individuals with PWS is a particularly severe and intractable behavioral issue that may be maintained by (as yet unknown) sensory consequences. Further studies to identify the determinants of skin picking in PWS are therefore needed. The implications for interventions are discussed.

The use of medical care and the prevalence of serious illness in an adult Prader-Willi syndrome cohort

INTRODUCTION

Adults with Prader-Willi syndrome (PWS) have an increased occurrence of several medical conditions. We report on the consequences of high morbidity rates such as prevalence rate of hospital admissions, medication use and surgery in a Dutch cohort of adults with PWS. Special attention is paid to causes and symptoms of serious illness.

METHOD

Participants were contacted via the Dutch Prader-Willi Parent Association and through physicians specializing in persons with ID. The persons with PWS and their main caregivers were visited at home. Information was collected through semi-structured interviews on 102 adults with PWS.

RESULTS

The need for medical care in the neonatal period is associated with hypotonia and feeding problems. Hospital admissions for respiratory tract infections are frequent. During childhood most hospital admissions were due to PWS syndrome specific surgery. During adolescence hospital admissions occurred for scoliosis surgery and endocrine evaluations. At adult age, hospitalization was associated with inguinal hernia surgery, diabetes mellitus, psychosis, erysipelas, water and drug intoxications. In the older group, respiratory infections were again the main reason for hospital admissions. Frequently used medications at adult age included psychotropics, laxatives, anti-diabetics and dermatologic preparations. Abnormal drinking patterns, problems with anesthesia, decreased ability to vomit, abnormal pain awareness and unpredictable fever responses were frequent and often lead to delayed diagnoses of serious conditions.

DISCUSSION

People with PWS are frequent users of medical-care. Reasons for hospitalization and medication use are age specific. Knowledge on the different presentation of symptoms in people with PWS is needed. In case of unexplained illness, disturbances of consciousness and behavioral changes in people with PWS, an infection should be ruled out in the first place. Information from this study may help in preventing conditions and recognizing conditions in an early stage. Adequate preventive management and treatment of PWS related morbidity, could reduce medical care use in the long term and could improve quality adjusted life years.

Genomic imprinting: an obsession with depilatory mice

Excessive grooming in mice has been promoted as a model of human obsessive-compulsive disorders. A recent paper adds Grb10 to the list of genes with effects on behavioral hair loss, with the added twist that this time the gene is imprinted.

Prader-Willi syndrome: A primer for clinicians

The advent of sensitive genetic testing modalities for the diagnosis of Prader-Willi syndrome has helped to define not only the phenotypic features of the syndrome associated with the various genotypes but also to anticipate clinical and psychological problems that occur at each stage during the life span. With advances in hormone replacement therapy, particularly growth hormone children born in circumstances where therapy is available are expected to have an improved quality of life as compared to those born prior to growth hormone.

This manuscript was prepared as a primer for clinicians-to serve as a resource for those of you who care for children and adults with Prader-Willi syndrome on a daily basis in your practices. Appropriate and anticipatory interventions can make a difference.

Is there a genomically imprinted social brain?

Imprinted genes (IGs) are expressed or silenced according to their parent-of-origin. These genes are known to play a role in regulating offspring growth, development and infant behaviors such as suckling and ultrasonic calls. In adults, neurally expressed IGs coordinate several behaviors including maternal care, sex, feeding, emotionality, and cognition. However, despite evidence from human psychiatric disorders and evolutionary theory that maternally and paternally expressed genes should also regulate social behavior, little empirical data from mouse research exists. This paper discusses data from a recent study (Garfield et al., 2011) that the IG Grb10 governs unique aspects of mouse social behavior and interprets the relevance of these findings for the future of this field.

Functional Assessment and Behavioral Treatment of Skin Picking in a Teenage Girl With Prader-Willi Syndrome

Skin picking is common in individuals with Prader-Willi Syndrome (PWS) but few treatment studies exist. This study reports the successful functional behavioral assessment (FBA) and treatment of skin picking in a 16-year-old female with PWS. A treatment package based on FBA results consisted of differential reinforcement for alternative and incompatible behavior, self-evaluation of progress, and reinforcement for weekly progress and participation in treatment. Pictures of wounds resulting from skin picking were taken during treatment. A total of 30 pictures were randomly selected and shown in a random order to 16 individuals unfamiliar with the study. The individuals then rated severity of the wounds displayed in the pictures. Pearson’s χ2 was used to assess changes in the ratings of severity during the course of treatment, and significant results indicate improvement over the course of intervention, χ 2(1) = 246.6, p < .001. This study adds to the very small literature on treatment of skin picking in people with PWS.