Associations between repetitive questioning, resistance to change, temper outbursts and anxiety in Prader-Willi and Fragile-X syndromes

The Effect of Anxiety and Autism Symptom Severity on Restricted and Repetitive Behaviors Over Time in Children with Fragile X Syndrome

Background

Restricted and repetitive behaviors (RRBs) are highly prevalent and reduce function in individuals with fragile X syndrome (FXS). As transdiagnostic features of intellectual disability, elevated rates of RRBs in FXS could represent various underlying known co-occurring conditions in FXS such as anxiety or autism spectrum disorder (ASD), yet this distinction has not been investigated. Further, delineating whether RRBs are more indicative of anxiety or ASD in FXS may clarify phenotypic profiles within FXS and improve differential assessment.

Methods

We longitudinally examined the potentially independent or multiplicative effect of ASD and anxiety symptom severity on RRBs in 60 children with FXS. Anxiety was measured using the Child Behavior Checklist (CBCL), ASD severity was measured using the Childhood Autism Rating Scale (CARS), and RRBs were measured using The Repetitive Behavior Scale - Revised (RBS-R). We estimated a series of moderated regression models with anxiety and ASD symptoms at the initial assessment (Time 1) as predictors of RRBs at the outcome assessment two years later (Time 2), along with an anxiety-by-ASD interaction term to determine the potential multiplicative effect of these co-occurring conditions on RRBs.

Results

Results identified a significant interaction between ASD and anxiety symptom severity at the initial assessment that predicted elevated sensory-motor RRBs two years later. Increased sensory-motor RRBs were predicted by elevated ASD symptoms only when anxiety symptom severity was low. Likewise, increased sensory-motor RRBs were predicted by elevated anxiety symptoms only when ASD symptom severity was low. Interestingly, this relationship was isolated to Sensory-Motor RRBs, with evidence that it could also apply to total RRBs.

Conclusions

Findings suggest that ASD and anxiety exert independent and differential effects on Sensory-Motor RRBs when at high severity levels and a multiplicative effect when at moderate levels.

Cognitive dysfunction and psychopathology: a cohort study of adults with intellectual developmental disorder

BACKGROUND

Cognitive impairment of intellectual developmental disorders (IDD) is determined by several different combinations of specific cognitive alterations. People with IDD present a rate of mental health problems that is up to 4 times higher than that of the general population. Despite this, the relationship between specific cognitive dysfunctions and co-occurring mental disorders has not been adequately studied. The aim of the present paper is to investigate the association between specific cognitive dysfunctions and specific psychiatric symptoms and syndromes in people with IDD.

METHODS

One hundred and twenty adults with mild to moderate IDD living in residential facilities underwent a clinical and instrumental assessment for specific cognitive and psychopathological features.

RESULTS

Participants with IDD and ASD have significantly lower scores compared to those without respect to who has not the diagnosis on the Processing Speed Index (PSI) and Perceptual Reasoning Index (PRI) on the WAIS-IV and higher time scores on the TMT A. Moreover, there is a significant association between years of hospitalisation and TMT B and TMT B A time scores; the longer a participant with IDD was hospitalised, the worse their performance on the TMT. Although not statistically significant, many psychopathological clusters showed substantial cognitive profiles.

CONCLUSIONS

Although further research is needed, neuropsychological and IQ tests scores seem to be differently associated to various psychopathological conditions co-occurring with IDD, and with ASD especially. Cognitive assessment seems to support diagnosis and treatment of psychopathological co-occurrences in persons with IDD, also in consideration of indirect implications including a better knowledge of the patient's characteristics beyond IQ deficit.

Behaviours that Challenge in SATB2-associated Syndrome: Correlates of Self-injury, Aggression and Property Destruction

SATB2-associated syndrome (SAS) is a genetic syndrome characterised by intellectual disability, severe speech delay, and palatal and dental problems. Behaviours that challenge (BtC) are reported frequently; however, there is limited research on specific forms of BtC and the correlates of these behaviours. The current study explores correlates of well-defined BtC, self-injury, aggression, and property destruction, in SAS. Eighty-one parents/caregivers of individuals with SAS (53.1% male, Mage 10.12 years) completed questionnaire measures of health, behavioural, emotional, and autism characteristics. Individuals with SAS were grouped based on caregiver responses to the presence or absence of self-injury, aggression, and property destruction on the Challenging Behaviour Questionnaire. Rates of self-injury, aggression and property destruction were 42%, 77% and 49%, respectively. Between-group comparisons were conducted to compare characteristics between behaviour groups. Significantly differing characteristics were entered into separate hierarchical logistic regressions for each form of BtC. Behavioural comparisons indicated variation in the characteristics associated with each behaviour. All hierarchical logistic regression models were significant (p < .001): self-injury (χ2(5) = 38.46, R2 = 0.571), aggression (χ2(4) = 25.12, R2 = 0.414), property destruction (χ2(4) = 23.70, R2 = 0.346), explaining between 34.6% and 57.1% of the variance in behaviour presence. This is the first study to identify correlates of self-injury, aggression, and property destruction in SAS. Variability in the characteristics associated with each behaviour highlights the importance of specificity when examining BtC. Understanding correlates of specific forms of BtC has important implications for informing SAS-associated pathways to behavioural outcomes and the implementation of tailored behavioural interventions.

Remote cognitive training for children with congenital brain malformation or genetic syndrome: a scoping review

Increased attention is arising on the delivery of remote cognitive interventions, which allow performing exercises in everyday settings, favouring rehabilitation continuity. The present study offers an overview of remote cognitive training programs for children with congenital brain malformation or genetic syndrome affecting the central nervous system, included in papers published in the time period 2011-2021. A total of 13 records was found and discussed including efficacy studies, feasibility studies and study protocols. Many studies have focused on a specific diagnosis, such as cerebral palsy, Down Syndrome, Fragile X Syndrome, while no or little evidence has been gathered on more rare diseases or brain malformations. Interventions were found to generate benefits on some cognitive functions, but problems with adherence were highlighted, especially due to excessive cognitive load from the training or clinical comorbidities. Conclusions remain tentative due to heterogeneity in training, study and patients characteristics, and methodological limitations of studies.

Behavioural and physiological indicators of anxiety reflect shared and distinct profiles across individuals with neurogenetic syndromes

Anxiety is heightened in individuals with intellectual disability, particularly in those with specific neurogenetic syndromes. Assessment of anxiety for these individuals is hampered by a lack of appropriate measures that cater for communication impairment, differences in presentation, and overlapping features with co-occurring conditions. Here, we adopt a multi-method approach to identify fine-grained behavioural and physiological (via salivary cortisol) responses to anxiety presses in people with fragile X (FXS; n = 27; Mage = 20.11 years; range 6.32 - 47.04 years) and Cornelia de Lange syndromes (CdLS; n = 27; Mage = 18.42 years; range 4.28 - 41.08 years), two neurogenetic groups at high risk for anxiety, compared to neurotypical children (NT; n = 21; Mage = 5.97 years; range 4.34 - 7.30 years). Results indicate that physical avoidance of feared stimuli and proximity seeking to a familiar adult are prominent behavioural indicators of anxiety/stress in FXS and CdLS. Heightened pervasive physiological arousal was identified in these groups via salivary cortisol. An association between autistic characteristics and anxiety was evident in the FXS group but not in the CdLS group pointing to syndrome-specific nuances in the association between anxiety and autism. This study furthers understanding of the behavioural and physiological presentation of anxiety in individuals with intellectual disability and progresses theoretical developments regarding the development and maintenance of anxiety at the intersection of autism.

Social Anxiety in Neurodevelopmental Disorders: The Case of Fragile X Syndrome

Despite significant advances in understanding and treating social anxiety in the general population, progress in this area lags behind for individuals with intellectual disability. Fragile X syndrome is the most common cause of inherited intellectual disability and is associated with an elevated prevalence rate of social anxiety. The phenotype of fragile X syndrome encompasses multiple clinically significant characteristics that are posed as risk markers for social anxiety in other populations. Here, evidence is reviewed that points to physiological hyperarousal, sensory sensitivity, emotion dysregulation, cognitive inflexibility, and intolerance of uncertainty as primary candidates for underlying mechanisms of heightened social anxiety in fragile X syndrome. A multilevel model is presented that provides a framework for future research to test associations.

Systematic Review: Emotion Dysregulation in Syndromic Causes of Intellectual and Developmental Disabilities

OBJECTIVE

To summarize the current state of the literature regarding emotion dysregulation (ED) in syndromic intellectual disabilities (S-IDs) in 6 of the most common forms of S-IDs-Down syndrome, fragile X syndrome (FXS), tuberous sclerosis complex, Williams syndrome, Prader-Willi syndrome, and Angelman syndrome-and to determine future research directions for identification and treatment of ED.

METHOD

PubMed bibliographic database was searched from date of inception to May 2021. PRISMA 2020 guidelines were followed with the flowchart, table of included studies, list of excluded studies, and checklist provided. Filters applied included human research and English. Only original research articles were included in the final set, but review articles were used to identify secondary citations of primary studies. All articles were reviewed for appropriateness by 2 authors and summarized. Inclusion criteria were met by 145 articles (Down syndrome = 29, FXS = 55, tuberous sclerosis complex = 11, Williams syndrome = 18, Prader-Willi syndrome = 24, Angelman syndrome = 8).

RESULTS

Each syndrome review was summarized separately and further subdivided into articles related to underlying neurobiology, behaviors associated with ED, assessment, and targeted intervention. FXS had the most thorough research base, followed by Down syndrome and Prader-Willi syndrome, with the other syndromes having more limited available research. Very limited research was available regarding intervention for all disorders except FXS.

CONCLUSION

Core underlying characteristics of S-IDs appear to place youth at higher risk for ED, but further research is needed to better assess and treat ED in S-IDs. Future studies should have a standard assessment measure of ED, such as the Emotion Dysregulation Inventory, and explore adapting established curricula for ED from the neurotypical and autism spectrum disorder fields.

Establishing the transdiagnostic contextual pathways of emotional outbursts

Emotional outbursts or temper outbursts are challenging behaviours commonly experienced by people with neurodevelopmental disorders and people who have experienced childhood adversity, which can negatively impact individuals and their families. Emotional outbursts may manifest in different situations via unique pathways distinguished by context-specific differences in the regulation and expression of emotions. Caregivers (N = 268) of young people (6-25 years) with emotional outbursts completed a bespoke caregiver-report questionnaire. Potential pathways were identified by examining the patterns of antecedents and setting events related to outbursts through factor and cluster analyses. Six contextual factors were derived from the Emotional Outburst Questionnaire. Based on these factors, the responses were classified into three clusters, which may represent potential pathways of emotional outbursts. The three clusters were characterized by the increased likelihood of outbursts: (1) across all setting events and triggers; (2) in safe setting events; (3) in unsafe setting events. These potential pathways may be related to: (1) differences in sensory processing; (2) masking of emotions in unsafe environments; (3) differences in safety perception. This framework supports a transdiagnostic account of emotional outbursts and may facilitate the development of pathway-specific intervention strategies.

Executive function, repetitive behaviour and restricted interests in neurodevelopmental disorders

BACKGROUND

Individuals with genetic syndromes show unique profiles of repetitive behaviours and restricted interests (RRBs). The executive dysfunction account of RRBs suggests that in autistic (AUT) individuals executive function impairments underpin RRBs, but not communication and social interaction autistic characteristics.

AIMS

To 1) describe profiles of behavioural manifestations of executive function (EF behaviours) and 2) explore the relationship between EF behaviours and autistic traits across individuals with Cornelia de Lange (CdLS), fragile X (FXS) and Rubinstein-Taybi syndromes (RTS), and AUT individuals.

METHOD

Carers completed the Behavior Rating Inventory of Executive Function - Preschool Version and the Social Communication Questionnaire. Data reporting on 25 individuals with CdLS (Mage = 18.60, SD = 8.94), 25 with FXS (Mage = 18.48, SD = 8.80), 25 with RTS (Mage = 18.60, SD = 8.65) and 25 AUT individuals (Mage = 18.52, SD = 8.65) matched on chronological age and adaptive ability were included in analyses.

RESULTS

All groups showed impairments across EF behaviours compared to two-to-three-year-old typically developing normative samples with no differences between groups. Different EF behaviours predicted RRBs in the syndrome groups with no associations found in the AUT group.

CONCLUSIONS

Syndrome related differences should be considered when developing targeted interventions that focus on EF behaviours and/or RRBs in these groups.

Anxiety in Angelman Syndrome

Angelman Syndrome (AS) is a neurodevelopmental disorder most commonly caused by the impaired expression of the maternal UBE3A gene on chromosome 15. Though anxiety has been identified as a frequently present characteristic in AS, there are limited studies examining anxiety in this population. Studies of anxiety in other neurodevelopmental disorders have found disorder specific symptoms of anxiety and age specific displays of anxiety symptoms. However, there is a consistent challenge in identifying anxiety in people with neurodevelopmental disorders given the lack of measurement instruments specifically designed for this population. Given the limited information about AS and anxiety, the aims of the current project were to (a) examine symptoms of anxiety in children with AS and (b) determine the correlates of anxiety in children with AS. Participants included 42 adult caregivers of youth with AS in the AS Natural History study who completed the Developmental Behavior Checklist (DBC). The results found that 26% of the sample demonstrated elevated symptoms of anxiety and established a relationship between elevated anxiety in youth with AS and higher levels of irritability, hyperactivity, self-absorbed behaviors, and disruptive/antisocial behaviors. Findings from this research provide a foundation for tailoring evidence-based assessments and treatments for youth with AS and anxiety.

The Feasibility and Effectiveness of a Novel, On-Line Social Skills Intervention for Individuals With Prader-Willi Syndrome

INTRODUCTION

People with neurodevelopmental disabilities, including Prader-Willi syndrome (PWS), are at heightened risk for the negative sequalae of loneliness, including depression and anxiety. While societal factors such as stigma or limited social opportunities contribute to loneliness, so too do deficits in social cognition and social skills. People with PWS have specific difficulties recognizing affect in others, accurately interpreting social interactions, and taking the perspectives of others. These features, combined with hyperphagia, rigidity, and insistence on sameness conspire to impede the abilities of people with PWS to make and sustain friendships and reduce feelings of loneliness.

METHODS

We developed and administered an intervention, Building Our Social Skills (BOSS), that aimed to improve social skill deficits in PWS. The 10-week intervention was administered on-line via Zoom to 51 young people with PWS in the U.S. (M age = 20.8, SD = 6.42). Two clinicians co-led groups of 6-8 participants in 30-min sessions, 3 times per week, and also trained 4 graduate students to co-lead groups with high fidelity. We used a pre-post intervention and 3-month follow-up design, with no control group, and mitigated this design limitation by triangulating across informants and methodologies. Specifically, parents completed the widely used Social Responsiveness Scale (SRS) and Child Behavior Checklist (CBCL), and participants were individually interviewed about their friendships and loneliness. Interview responses were reliably coded by independent raters.

RESULTS

Repeated measure multivariate analyses, with baseline values entered as covariates, revealed significant pre-to post-test improvements in the SRS's social cognition, motivation and communication subscales (p's < 0.001), with large effect sizes ( n p 2 = 0.920, 0.270, and 0.204, respectively). Participant and parental reports of loneliness were correlated with the CBCL's Internalizing domain, specifically the Anxiety/Depressed subdomain. Over time, parents reported getting along better with peers, increased contact with friends, more friends and less loneliness. Participants also reported significantly less loneliness and more friends.

CONCLUSIONS

This mixed method, proof-of-concept study demonstrated the feasibility of delivering an on-line social skills intervention to young people with PWS. As no differences were found between clinician vs. graduate student outcomes, the BOSS curriculum holds considerable promise for wider dissemination and implementation in the PWS community.

Understanding the psycho-social context for a new early intervention for resistance to change that aims to strike a beneficial balance between structure and flexibility

BACKGROUND

Emotional and behavioural problems linked to changes to expectations - resistance to change - are linked to disability in neurodevelopmental disorders, including autism spectrum disorder (ASD), Prader-Willi (PWS) and fragile X syndromes (FXS). Structuring routines is best practice for minimising current resistance to change. But complete structure is impractical and flexibility in early life may actually reduce later resistance by supporting cognitive development. We aimed to examine the psycho-social context of families with children at risk of developing resistance to change so as to identify design requirements for an intervention that strikes a beneficial balance between structure and flexibility.

METHODS

Thirty-six caregivers of children aged 4-12 years (17 ASD, 15 PWS, and 4 FXS) took part in an interview designed collaboratively with 12 professional stakeholders.

RESULTS

Children need to feel like they are in control of flexibility but they also need support in choice making, understanding plans (using individually tailored visuals) and anxiety reduction. Caregivers need an accessible approach that they have full control over, and which they can tailor for their child. Caregivers also need clear guidance, education and support around structure and flexibility.

CONCLUSIONS

We propose a digital approach which addresses the needs identified. It tackles the most perplexing challenge by presenting flexibility to children in the context of a game that children can feel they have full control over, whilst caregivers can maintain control in reality. Furthermore, individualised support for children and caregivers would be enabled.

Behavioral Inflexibility Across Two Neurogenetic Conditions: Down Syndrome and Fragile X Syndrome

Behavioral inflexibility (BI) has been highlighted to occur across genetic and neurodevelopmental disorders. This study characterized BI in two common neurogenetic conditions: Fragile X syndrome (FXS) and Down syndrome (DS). Caregivers of children with FXS (N = 56; with ASD = 28; FXS only = 28) and DS (N = 146) completed the Behavioral Inflexibility Scale (BIS) via an online survey. Total BIS scores were higher in FXS+ASD than both FXS only and DS (p <.001). Most endorsed items were similar across the three groups, but scores were higher in the FXS+ASD group. In all groups, BI associated with other clinical variables (receptive behaviors, anxiety, social communication). The current data suggest that BI is variable across neurogenetic conditions and higher in individuals with comorbid ASD.

Behavioral features in Prader-Willi syndrome (PWS): consensus paper from the International PWS Clinical Trial Consortium

Prader-Willi syndrome (PWS) is a rare neurodevelopmental genetic disorder associated with a characteristic behavioral phenotype that includes severe hyperphagia and a variety of other behavioral challenges such as temper outbursts and anxiety. These behaviors have a significant and dramatic impact on the daily functioning and quality of life for the person with PWS and their families. To date, effective therapies addressing these behavioral challenges have proven elusive, but several potential treatments are on the horizon. However, a limiting factor for treatment studies in PWS is the lack of consensus in the field regarding how to best define and measure the complex and interrelated behavioral features of this syndrome. The International PWS Clinical Trials Consortium (PWS-CTC, www.pwsctc.org) includes expert PWS scientists, clinicians, and patient advocacy organization representatives focused on facilitating clinical trials in this rare disease. To address the above gap in the field, members of the PWS-CTC “Behavior Outcomes Working Group” sought to develop a unified understanding of the key behavioral features in PWS and build a consensus regarding their definition and description. The primary focus of this paper is to present consensus definitions and descriptions of key phenotypic PWS behaviors including hyperphagia, temper outbursts, anxiety, obsessive–compulsive behaviors, rigidity, and social cognition deficits. Patient vignettes are provided to illustrate the interrelatedness and impact of these behaviors. We also review some available assessment tools as well as new instruments in development which may be useful in measuring these behavioral features in PWS.

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 cross-syndrome approach to the social phenotype of neurodevelopmental disorders: Focusing on social vulnerability and social interaction style

BACKGROUND

Following Annette Karmiloff-Smith's approach to cognitive research, this study applied a cross-syndrome approach to the social phenotype, focusing on social vulnerability (SV) and the factors that contribute to it.

AIMS

To (i) identify syndrome-specific differences in SV across four neurodevelopmental disorder (NDD) groups, (ii) determine the contribution of intellectual disability (ID), age or gender to SV, and (iii) explore its relationship with social interaction style (SIS).

METHODS AND PROCEDURES

262 parents of children: Autism (n = 29), Williams syndrome (n = 29), Attention deficit hyperactivity disorder (n = 36), Fragile X syndrome (n = 18), and Neurotypical (n = 150) reported on their child's SV, quality of SIS and other factors (ID, age, gender).

OUTCOMES AND RESULTS

Heightened SV was not syndrome-specific. Instead it was found equally across NDD groups (and not in the neurotypical group), and independently of ID, age and gender. Different atypical SISs were also distributed across NDD groups and each were significantly related to SV, independent of the factors above and beyond neurodevelopmental diagnosis.

CONCLUSIONS AND IMPLICATIONS

The findings emphasise that social phenotypes are best understood as distributed across diagnostic boundaries and offer opportunities to further test the role of varied atypical SISs in the development of heightened SV.

Restricted and Repetitive Behaviors in Males and Females with Fragile X Syndrome: Developmental Trajectories in Toddlers Through Young Adults

There is limited research on the trajectory of restricted and repetitive behaviors (RRBs) in fragile X syndrome (FXS), with previous studies only examining males and/or examining RRBs as a unitary construct rather than delineating subtypes of RRBs. Thus, we described the trajectory of five subtypes of RRBs in 153 males and females with FXS (aged 1-18 years) with repeated measurement over time (445 total assessments). Multilevel modeling was used to test age-related differences in RRB subtypes between males and females with FXS, controlling for nonverbal IQ. Results showed that lower-order Sensory-Motor behaviors decreased over time for both males and females, while there was no significant change in the higher-order RRBs. The trajectory between males and females differed for Self-Injury.

Psychological treatment strategies for challenging behaviours in neurodevelopmental disorders: what lies beyond a purely behavioural approach?

PURPOSE OF REVIEW

Challenging behaviour shown by individuals with neurodevelopmental disorders (NDDs) has a major negative impact. There is robust evidence for the efficacy of treatments based on applied behaviour analysis. However, such approaches are limited in important ways - providing only part of the whole solution. We reviewed the literature to provide an overview of recent progress in psychological treatments for challenging behaviour and how these advance the field beyond a purely behavioural approach.

RECENT FINDING

We identified 1029 articles via a systematic search and screened for those implementing a psychological intervention with individuals with NDD (or caregivers) and measuring the potential impact on challenging behaviour. Of the 69 included studies published since 2018, more than 50% implemented a purely behavioural intervention. Other studies could generally be categorized as implementing parent training, meditation, skill training or technology-assisted interventions.

SUMMARY

Greater consideration of the interplay between behavioural and nonbehavioural intervention components; systematic approaches to personalization when going beyond the behavioural model; mental health and broad social communication needs; and models that include cognitive and emotional pathways to challenging behaviour; is needed to advance the field. Furthermore, technology should not be overlooked as an important potential facilitator of intervention efforts.

Food and Non-Food-Related Behavior across Settings in Children with Prader-Willi Syndrome

This study sought to describe food- and non-food-related behaviors of children aged 3 to 18 years with Prader–Willi syndrome (PWS) in home and school settings, as assessed by 86 parents and 63 teachers using 7 subscales of the Global Assessment of Individual’s Behavior (GAIB). General Behavior Problem, Non-Food-Related Behavior Problem, and Non-Food-Related Obsessive Speech and Compulsive Behavior (OS/CB) scores did not differ significantly between parent and teacher reports. Food-Related Behavior Problem scores were higher in parent versus teacher reports when the mother had less than a college education (difference of 13.6 points, 95% Confidence Interval (CI) 5.1 to 22). Parents assigned higher Food-Related OS/CB scores than teachers (difference of 5.7 points, 95% CI 2.4 to 9.0). Although teachers reported fewer Food-Related OS/CB, they scored overall OS/CB higher for interfering with daily activities compared with parents (difference of 0.9 points, 95% CI 0.4 to 1.4). Understanding how behaviors manifest in home and school settings, and how they vary with socio-demographic and patient characteristics can help inform strategies to reduce behavior problems and improve outcomes.

Defining Mental and Behavioural Disorders in Genetically Determined Neurodevelopmental Syndromes with Particular Reference to Prader-Willi Syndrome

Genetically determined neurodevelopmental syndromes are frequently associated with a particular developmental trajectory, and with a cognitive profile and increased propensity to specific mental and behavioural disorders that are particular to, but not necessarily unique to the syndrome. How should these mental and behavioural disorders best be conceptualised given that similar symptoms are included in the definition of different mental disorders as listed in DSM-5 and ICD-10? In addition, a different conceptual framework, that of applied behavioural analysis, has been used to inform interventions for what are termed 'challenging behaviours' in contrast to types of interventions for those conditions meeting diagnostic criteria for a 'mental disorder'. These syndrome-specific developmental profiles and associated co-morbidities must be a direct or indirect consequence of the genetic abnormality associated with that syndrome, but the genetic loci associated with the syndrome may not be involved in the aetiology of similar symptoms in the general population. This being so, should we expect underlying brain mechanisms and treatments for specific psychopathology in one group to be effective in the other? Using Prader-Willi syndrome as an example, we propose that the conceptual thinking that informed the development of the Research Domain Criteria provides a model for taxonomy of psychiatric and behavioural disorders in genetically determined neurodevelopmental syndromes. This model brings together diagnostic, psychological and developmental approaches with the aim of matching specific behaviours to identifiable neural mechanisms.

Transcutaneous vagus nerve stimulation (t-VNS): A novel effective treatment for temper outbursts in adults with Prader-Willi Syndrome indicated by results from a non-blind study

Temper outbursts are a severe problem for people with Prader-Willi Syndrome (PWS). Previous reports indicate that vagus nerve stimulation (VNS) may reduce maladaptive behaviour in neurodevelopmental disorders, including PWS. We systematically investigated the effectiveness of transcutaneous VNS (t-VNS) in PWS. Using a non-blind single case repeat measures modified ABA design, with participants as their own controls, t-VNS was evaluated in five individuals with PWS [three males; age 22-41 (M = 26.8)]. After a baseline phase, participants received four-hours of t-VNS daily for 12 months, followed by one month of daily t-VNS for two-hours. The primary outcome measure was the mean number of behavioural outbursts per day. Secondary outcomes included findings from behavioural questionnaires and both qualitative and goal attainment interviews. Four of the five participants who completed the study exhibited a statistically significant reduction in number and severity of temper outbursts after approximately nine months of daily four-hour t-VNS. Subsequent two-hour daily t-VNS was associated with increased outbursts for all participants, two reaching significance. Questionnaire and interview data supported these findings, the latter indicating potential mechanisms of action. No serious safety issues were reported. t-VNS is an effective, novel and safe intervention for chronic temper outbursts in PWS. We propose these changes are mediated through vagal projections and their effects both centrally and on the functioning of the parasympathetic nervous system. These findings challenge our present biopsychosocial understanding of such behaviours suggesting that there is a single major mechanism that is modifiable using t-VNS. This intervention is potentially generalizable across other clinical groups. Future research should address the lack of a sham condition in this study along with the prevalence of high drop out rates, and the potential effects of different stimulation intensities, frequencies and pulse widths.

Cognitive Training Targeting Planning Dysfunction in Adults with Prader-Willi Syndrome: Brief Report of a Study Protocol

Background: Prader-Willi syndrome (PWS) is a neurodevelopmental genetic disorder involving executive deficits notably with planning. The main objective of the study is to assess the effectiveness of cognitive training on daily life planning difficulties in PWS patients. Methods/design: The study is a double-blind randomized controlled trial which will compare the effectiveness of a metacognitive strategy intervention designed to improve planning difficulties for PWS patients to usual occupational therapy. Sixty adults will be included over 20 months. The main outcome measure will be the performance on the Modified Six Elements Test from the BADS; secondary outcome measures will be computerized executive tasks and questionnaires. Daily life planning difficulties will be identified and transformed into measurable goals using Goal Attainment Scaling. Discussion: The project will provide knowledge on the difficulties experienced by PWS patients, in relation to their executive functioning in order to implement effective intervention for planning in daily life.

Effects of mavoglurant on visual attention and pupil reactivity while viewing photographs of faces in Fragile X Syndrome

BACKGROUND

Numerous preclinical studies have supported the theory that enhanced activation of mGluR5 signaling, due to the absence or reduction of the FMR1 protein, contributes to cognitive and behavioral deficits in patients with fragile X syndrome (FXS). However multiple phase 2 controlled trials in patients with FXS have failed to demonstrate efficacy of compounds that negatively modulate mGluR5, including two phase 2b randomized controlled trials (RCT) of mavoglurant (AFQ056, Novartis Pharma AG), when the primary measures of interest were behavioral ratings. This has cast some doubt onto the translation of the mGluR5 theory from animal models to humans with the disorder.

METHODS

We evaluated social gaze behavior-a key phenotypic feature of the disorder-and sympathetic nervous system influence on pupil size using a previously-validated eye tracking paradigm as a biobehavioral probe, in 57 adolescent or adult patients with FXS at baseline and following three months of blinded treatment with one of three doses of mavoglurant or placebo, within the context of the AFQ056 RCTs.

RESULTS

Patients with FXS treated with mavoglurant demonstrated increased total absolute looking time and number of fixations to the eye region while viewing human faces relative to baseline, and compared to those treated with placebo. In addition, patients had greater pupil reactivity to faces relative to baseline following mavoglurant treatment compared to placebo.

DISCUSSION

The study shows that negative modulation of mGluR5 activity improves eye gaze behavior and alters sympathetically-driven reactivity to faces in patients with FXS, providing preliminary evidence of this drug's impact on behavior in humans with the disorder.

Parental Intention to Support the Use of Computerized Cognitive Training for Children With Genetic Neurodevelopmental Disorders

Children with genetic neurodevelopmental disorders (NDDs) such as Down syndrome, Prader-Willi syndrome, and Fragile X syndrome may show a range of cognitive impairments, including impairments in executive functions (EF). EF are related to general intelligence, academic achievement, and literacy and mathematical skills. EF deficits are linked to a variety of clinically and socially important behaviors. Therefore, methods for improving EF in children with NDDs could be beneficial. One method for improving EF is through cognitive training. Research on commercial brain training programmes and video games suggests that EF can be improved through training, both in healthy adults and in children with NDDs. Computerized cognitive training (CCT) therefore represents a potentially viable intervention for children with NDDs. For training to be effective, it is important that an appropriate regimen is followed. Since children are likely to engage with training at home, the intentions of their parents to support them are therefore important. However, no research has investigated the attitudes of parents of children with NDDs to CCT. To address this, we developed a questionnaire based on the theory of planned behavior, which states that a person's intention to engage in a behavior is predicted by (1) their attitude toward the behavior, (2) their perception of subjective norms regarding the behavior (i.e., perceived social pressure), and (3) their perceived control over the behavior. The questionnaire was completed by parents of children with NDDs; 58 unique responses were retained for analyses. Parents reported low levels of knowledge of CCTs, and low levels of experience with CCTs (both their own experience and their child's experience). However, our results also show that parents of children with NDDs have positive beliefs about the potential of CCT to benefit their children and intend to support the use of CCT by their children. Linear modeling showed that, of the three constructs of the theory of planned behavior, only attitudes significantly predicted intention. Finally, parents' beliefs about the benefits of CCT correlated positively with positive attitudes toward such training. We also found limited evidence that parents of boys have more positive attitudes regarding CCT than parents of girls.

Rigidity in routines and the development of resistance to change in individuals with Prader-Willi syndrome

BACKGROUND

Individuals with Prader-Willi syndrome (PWS) commonly show debilitating resistance to change, which has been linked to cognitive deficits in task switching. Anecdotal reports suggest that exposure to flexibility in routines during development may be beneficial for limiting subsequent resistance to change in people with PWS, which is consistent with a beneficial role of such exposure on the development of task switching, highlighted in typical children. Here, we aim to investigate the development of resistance to change in individuals with PWS and hypothesise that exposure to increased rigidity in routines will be associated with increased subsequent resistance to change.

METHODS

An author-compiled informant report interview and two previously validated questionnaires were administered to the caregivers of 10 individuals with PWS (5-23 years). The interview examined rigidity in routines and resistance to change across life stages defined by easily distinguishable events (before school, during primary school, during secondary school, after school, currently), using open-ended and structured yes/no and 5-point Likert questions. Open-ended data were coded using an author-compiled system. Responses from two additional informants and data from the questionnaires were used to assess inter-informant reliability and concurrent validity of the structured questions.

RESULTS

The validity of the interview was supported by acceptable inter-rater reliability of the open-ended coding system and inter-informant reliability, internal consistency and concurrent validity of structured questions. Descriptive analyses of ratings of behaviour change showed a pattern of increasing resistance to change over the life course for the four oldest individuals, who had all been exposed to substantial rigidity in routines before and during primary school. Furthermore, only one individual - currently in primary school - was exposed to very little rigidity in routines before and during primary school, and he had showed a decrease in resistance to change after entering primary school. Open-ended data showed that more individuals currently evidencing little resistance to change had been exposed to parent or self-imposed flexibility in routines, than those currently evidencing substantial resistance to change. However, correlational analyses on rigidity and resistance to change ratings highlighted the possibility that rigidity during primary school is most relevant for developing resistance to change. Finally, open-ended data emphasised an important beneficial role of rigidity in routines for limiting the current challenging behaviour of individuals with high resistance to change.

CONCLUSION

Because task switching appears to evidence a period of high developmental sensitivity during early primary school years, we propose that this period may represent a critical time when increasing flexibility in the routines of children with PWS could limit the development of resistance to change. However, a careful balance would need to be struck, given the apparent benefit of rigid routines on current behaviour. Further work in this area is much needed.

Signalling changes to individuals who show resistance to change can reduce challenging behaviour

BACKGROUND & OBJECTIVES

Several neurodevelopmental disorders are associated with resistance to change and challenging behaviours - including temper outbursts - that ensue following changes to routines, plans or expectations (here, collectively: expectations). Here, a change signalling intervention was tested for proof of concept and potential practical effectiveness.

METHODS

Twelve individuals with Prader-Willi syndrome participated in researcher- and caregiver-led pairing of a distinctive visual-verbal signal with subsequent changes to expectations. Specific expectations for a planned subset of five participants were systematically observed in minimally manipulated natural environments. Nine caregivers completed a temper outburst diary during a four week baseline period and a two week signalling evaluation period.

RESULTS

Participants demonstrated consistently less temper outburst behaviour in the systematic observations when changes imposed to expectations were signalled, compared to when changes were not signalled. Four of the nine participants whose caregivers completed the behaviour diary demonstrated reliable reductions in temper outbursts between baseline and signalling evaluation.

LIMITATIONS

An active control group for the present initial evaluation of the signalling strategy using evidence from caregiver behaviour diaries was outside the scope of the present pilot study. Thus, findings cannot support the clinical efficacy of the present signalling approach.

CONCLUSIONS

Proof of concept evidence that reliable pairing of a distinctive cue with a subsequent change to expectation can reduce associated challenging behaviour is provided. Data provide additional support for the importance of specific practical steps in further evaluations of the change signalling approach.

Cognition in people with Prader-Willi syndrome: Insights into genetic influences on cognitive and social development

We present a mini-review of cognition in Prader-Willi syndrome. Studies cited include findings on general ability (IQ), IQ correlates with family members, strengths and weaknesses in cognitive profiles in genetic subtypes, attainment in literacy and numeracy, language, comprehension, modality preferences, executive functions, and social cognition. The latter includes investigations of theory of mind, emotion recognition, face processing and knowledge of social norms. Results from research on mouse models and brain imaging studies relevant to cognition are briefly discussed. The importance of these studies to understanding and managing education and behaviour in PWS and the limitations of the studies in terms of small numbers, non-representativeness, and lack of replication is also touched upon.

Prader-Willi syndrome mental health research strategy workshop proceedings: the state of the science and future directions

Abstract

This paper reports on the ‘Prader-Willi Syndrome (PWS) Mental Health Research Strategy Workshop’ that took place in March 2015. PWS is characterized by a complex phenotype affecting multiple systems with a high prevalence of maladaptive behaviours, and neuropsychiatric illness. Prader Willi syndrome results from the absence of paternally derived alleles located at the imprinted chromosomal locus, 15q11–13. The goal of the workshop was to highlight the state of the science of the mental health of people with this rare neurodevelopmental disorder. Mental ill health and maladaptive behaviors significantly impact quality of life for persons with PWS and their caregivers. Effective treatments and further research into this area are critically needed.

Methods

A multidisciplinary group of scientists and health care professionals were brought together to discuss the mental health and behavioral needs of people with PWS. The workshop strategy was to integrate established work on PWS with other relevant areas of study. The meeting also focused on two neurobiological systems that research had suggested were relevant to understanding the broader mental health aspects of PWS: the autonomic nervous system and oxytocin/vasopressin pathways. Other relevant topics were considered and recommendations made.

Results

The workshop presentations and working group discussions revealed that no one approach was sufficient to fully conceptualize the mental health challenges in PWS. Workshop discussions pointed to the need for theoretically informed studies focused on clinical characterization, measurement, and the probing of specific neurobiological systems through pharmaceutical or other interventions. Future studies in this area should explore the use of advanced neuroimaging protocols, as well as molecular studies using iPS cells in order to create more informed theories.

Conclusions

Within this framework, workshop participants identified and prioritized key research questions, and highlighted current opportunities. Recommendations were made with respect to the development of specific resources and tools for furthering mental health research such as The Global PWS Registry, the development of effective endpoints, the use of animal models and iPS cells to aid understanding of the neurobiological underpinnings. Additionally, collaborative opportunities across disciplines and syndromes were highlighted and targeted research initiatives focused on psychological/behavioral interventions modified for use in PWS were recommended.

The role of anxiety in vulnerability for self-injurious behaviour: studies in a rodent model

Self-injurious behaviour (SIB) is a debilitating characteristic that is highly prevalent in autism and other neurodevelopmental disorders. Pathological anxiety is also common, and there are reports of comorbid anxiety and self-injury in some children. We have investigated potential interactions between anxiety and self-injury, using a rat model of pemoline-induced self-biting. In one experiment, rats were pre-screened for trait anxiety by measuring expression of anxiety-related behaviour on the elevated plus maze and open field emergence test. The rats were then treated with pemoline once daily for ten days, and vulnerability for pemoline-induced self-injury was evaluated. This revealed modest correlations between innate levels of anxiety-related behaviour in the open field test (time in the start box, and latency to enter the open field), and vulnerability for pemoline-induced self-biting (total duration of self-injurious oral contact, and total size of tissue injury). Measures in the elevated plus maze were not significantly correlated with vulnerability for pemoline-induced self-injury. In a second experiment, rats were treated with the beta-carboline FG 7142 twice daily, during 5days of treatment with pemoline. The rats that were treated with this anxiogenic drug exhibited greater duration of self-injurious oral contact, and larger injuries than vehicle-treated controls did. Overall, these results suggest that anxiety may contribute to the etiology and/or expression of self-injurious behaviour, and indicate that further research is warranted.

Physiological Correlates of Maternal Responsivity in Mothers of Preschoolers With Fragile X Syndrome

The present study examined the relationship between salivary cortisol and maternal responsiveness in mothers of boys with fragile X syndrome (FXS). Maternal responsivity is strongly associated with child outcomes, and children with FXS are at risk for compromised development due to intellectual disability and problem behavior. Increased understanding of the nature and underlying mechanisms of maternal responsivity in FXS is important to optimize outcomes in children with FXS and contribute to improved family cohesion. Data from 36 mother-child dyads indicated a complex age effect with elevated cortisol levels associated with high maternal responsivity scores when children are young and low responsivity scores when children are older. Implications of these findings and directions for future research are discussed.

Increased Exposure to Rigid Routines can Lead to Increased Challenging Behavior Following Changes to Those Routines

Several neurodevelopmental disorders are associated with preference for routine and challenging behavior following changes to routines. We examine individuals with Prader-Willi syndrome, who show elevated levels of this behavior, to better understand how previous experience of a routine can affect challenging behavior elicited by disruption to that routine. Play based challenges exposed 16 participants to routines, which were either adhered to or changed. Temper outburst behaviors, heart rate and movement were measured. As participants were exposed to routines for longer before a change (between 10 and 80 min; within participants), more temper outburst behaviors were elicited by changes. Increased emotional arousal was also elicited, which was indexed by heart rate increases not driven by movement. Further study will be important to understand whether current intervention approaches that limit exposure to changes, may benefit from the structured integration of flexibility to ensure that the opportunity for routine establishment is also limited.

Examining the operant function of challenging behavior in young males with fragile X syndrome: a summary of 12 cases

This study used experimental functional analyses to examine the operant function of challenging behaviors exhibited by 12 males (ages 27-51 months) with fragile X syndrome (FXS). Eight children met criteria for negatively reinforced challenging behavior in the form of escape from demands and/or escape from social interactions. Nine children met criteria for positively reinforced challenging behavior in the form of obtaining access to highly preferred items. Attention was identified as a maintaining consequence for three children. The functional analysis was inconclusive for one child. Results suggest that, for young males with FXS, challenging behaviors may more likely be tangibly and escape maintained than attention maintained. Our findings affirm past research suggesting a unique behavioral phenotype for this population.

The prevalence of aggression in genetic syndromes: a review

Research into behavioural phenotypes identifies both environmental and organic factors as influencing aggression in children and adults with genetic disorders associated with intellectual disability. However, in contrast to self-injury there is a paucity of research that compares aggression across relevant syndromes. The primary aim of this review is to examine the association between aggression and genetic syndromes by analysis of prevalence studies. The review also examines the literature on the form of the behaviour and influence of environmental factors. Results imply that certain syndrome groups (Cri du Chat, Smith-Magenis, Prader-Willi, Angelman, Cornelia de Lange, and Fragile X syndromes; estimates over 70%) evidence a stronger association with aggression than others (e.g. Williams and Down syndromes; estimates below 15%). However, the strength of association is difficult to quantify due to methodological differences between studies. The results from examining form and environmental influences highlight the importance of phenotype-environment interactions. Research employing group comparison designs is warranted and future work on the assessment and intervention of aggression in genetic syndromes should consider the importance of phenotype-environment interactions.

Temperament factor structure in fragile X syndrome: the children's behavior questionnaire

Early patterns of temperament lay the foundation for a variety of developmental constructs such as self-regulation, psychopathology, and resilience. Children with fragile X syndrome (FXS) display unique patterns of temperament compared to age-matched clinical and non-clinical samples, and early patterns of temperament have been associated with later anxiety in this population. Despite these unique patterns in FXS and recent reports of atypical factor structure of temperament questionnaires in Williams Syndrome (Leyfer, John, Woodruff-Borden, & Mervis, 2012), no studies have examined the latent factor structure of temperament scales in FXS to ensure measurement validity in this sample. The present study used confirmatory factor analysis to examine the factor structure of a well-validated parent-reported temperament questionnaire, the Children's Behavior Questionnaire (Rothbart, Ahadi, Hershey, & Fisher, 2001), in a sample of 90 males with FXS ages 3-9 years. Our data produced a similar, but not identical, three-factor model that retained the original CBQ factors of negative affectivity, effortful control, and extraversion/surgency. In particular, our FXS sample demonstrated stronger factor loadings for fear and shyness than previously reported loadings in non-clinical samples, consistent with reports of poor social approach and elevated anxiety in this population. Although the original factor structure of the Children's Behavior Questionnaire is largely retained in children with FXS, differences in factor loading magnitudes may reflect phenotypic characteristics of the syndrome. These findings may inform future developmental and translational research efforts.

Temper outbursts in Prader-Willi syndrome: causes, behavioural and emotional sequence and responses by carers

BACKGROUND

Temper outbursts are common in Prader-Willi syndrome but rarely described in detail. This study investigated the phenomenology of temper outbursts in terms of antecedents, sequence of behaviours and emotions and intervention strategies used.

METHOD

A semi-structured interview about temper outbursts was conducted with the main carers of seven children (9.5 to 16.7 years) and seven adults (24.7 to 47.10 years) with Prader-Willi syndrome (10 male, 4 female). Reliability and validity of the interview results was established.

RESULTS

Various setting events increased and reduced the likelihood of temper outbursts. The most common antecedent was a change to routine or expectation. There were marked similarities in the sequence of behaviours and emotions during temper outbursts, with anger rising quickly followed by expressions of remorse and distress at the end of an outburst.

DISCUSSION

The sequence of behaviours and emotions within outbursts was similar to that described in temper tantrums in typical development. Cognitive and emotional processes are likely to be important in the understanding of temper outbursts with implications for early intervention.

Correlates of self-injurious, aggressive and destructive behaviour in children under five who are at risk of developmental delay

AIM

Several behavioural correlates of self-injury, aggression and destructive behaviour have been identified in children and young adults with intellectual disabilities. This cross-sectional study aimed to further explore these correlates in very young children with developmental delay.

METHODS

Parents of 56 children (40 male) under the age of five years (mean age 2 years 10 months) completed a questionnaire about their child's behaviour and the presence of behavioural correlates, including repetitive, over-active or impulsive behaviour and more severe developmental delay.

RESULTS

Parents reported very high prevalence of self-injurious, aggressive and destructive behaviour: 51%, 64% and 51%, respectively. A binary logistic regression revealed that a higher score on a measure of overactive and impulsive behaviour significantly predicted the presence of destructive behaviour. A multiple linear regression revealed that both repetitive behaviour and number of health problems approached significance as independent predictors of severe self-injurious behaviour.

INTERPRETATION

Despite the very small sample, several factors emerged as potential predictors of self-injurious, aggressive and destructive behaviour. These findings support the need for further investigation in a larger sample. Confirmation in this age group could help guide the development of targeted early intervention for these behaviours by identifying behavioural risk markers.

[Behavioral characteristics of children with Prader-Willi syndrome in preschool and school age: an exploratory study on ritualistic behavior]

Parents of 64 children and youths with Prader-Willi syndrome (PWS) describe their children's behaviour on the "Temperament and Atypical Behavior Scale" (TABS) and the German version of the "Developmental Behavior Checklist" (VFE). In the younger age group, there are no specific behavioural abnormalities which characterize a behavioral phenotype. In the older age group the data reveal elevated levels of abnormal behaviors (communication disturbance, social relations and disruptive behaviors). Parents stress ritualistic behaviors as especially challenging. The results concerning form and age-dependency of abnormal behaviors are discussed in the context of prevention and treatment options.

Behavioral intervention for problem behavior in children with fragile X syndrome

Parents and professionals typically report problem behavior as a significant concern for children with fragile X syndrome. In the present study, the authors explored whether behaviorally based interventions would result in a reduction in problem behavior and an improvement in quality of life for 3 children with fragile X syndrome and their families. A multiple baseline design was used to demonstrate intervention effects for specific high-priority contexts (i.e., bedtime, running errands, and toileting). A multicomponent intervention plan was developed to teach the parents and child to effectively cope with the particular context. After intervention, there were substantial improvements in problem behavior and family quality of life within the given contexts. Results of this study demonstrated the effectiveness of behavioral intervention for children with fragile X syndrome.

Phenotype-environment interactions in genetic syndromes associated with severe or profound intellectual disability

The research literature notes both biological and operant theories of behavior disorder in individuals with intellectual disabilities. These two theories of genetic predisposition and operant reinforcement remain quite distinct; neither theory on its own is sufficient to explain challenging behavior in genetic syndromes and an integrated approach is required. This literature review integrates the two approaches by exploring how environmental factors can influence problem behavior in genetic syndromes associated with intellectual disability. Particular attention is paid to studies that describe evidence that problem behaviors in syndromes that are considered to be phenotypic are associated with other aspects of an established behavioral phenotype. The review highlights how the study of phenotype-environment interactions within syndromes can promote understanding of the aetiology of problem behaviors both within genetic syndromes and, ultimately, the wider population of individuals with severe intellectual disabilities. The review also evaluates the current status of research and the methods typically employed. Implications for intervention, future research and extending existing causal models of challenging behavior are discussed.

Neurobehavioral phenotype in Prader-Willi syndrome

The focus of this article is on the lifetime development of people with Prader-Willi syndrome (PWS) and specifically on the neurobehavioral phenotype. We consider studies of this aspect of the phenotype (the "behavioral phenotype" of the syndrome) that have confirmed that there are specific behaviors and psychiatric disorders, the propensities to which are increased in those with PWS, and cannot be accounted for by other variables such as IQ or adaptive behavior. Beginning with a description of what is observed in people with PWS, we review the evolving PWS phenotype and consider how some aspects of the phenotype might be best explained, and how this complex phenotype may relate to the equally complex genotype. We then consider in more detail some of the neurobehavioral aspects of the phenotype listed above that raise the greatest management problems for parents and carers.

The relationship between specific cognitive impairment and behaviour in Prader-Willi syndrome

BACKGROUND

Individuals with Prader-Willi syndrome (PWS) have been shown to demonstrate a particular cognitive deficit in attention switching and high levels of preference for routine and temper outbursts. This study assesses whether a specific pathway between a cognitive deficit and behaviour via environmental interaction can exist in individuals with PWS.

METHODS

Four individuals with PWS participated in a series of three single-case experiments including laboratory-based and natural environment designs. Cognitive (computer-based) challenges placed varying demands on attention switching or controlled for the cognitive demands of the tasks while placing no demands on switching. Unexpected changes to routines or expectations were presented in controlled games, or imposed on participants' natural environments and compared with control conditions during which no unexpected changes occurred. Behaviour was observed and heart rate was measured.

RESULTS

Participants showed significantly increased temper outburst related behaviours during cognitive challenges that placed demands on attention switching, relative to the control cognitive challenges. Participants showed significantly increased temper outburst related behaviours when unexpected changes occurred in an experimental or the natural environment compared with when no changes occurred.

CONCLUSIONS

Difficult behaviours that could be triggered reliably in an individual by a specific cognitive demand could also be triggered via manipulation of the environment. Results suggest that a directional relationship between a specific cognitive deficit and behaviour, via environmental interaction, can exist in individuals with PWS.

Examining the function of problem behavior in fragile X syndrome: preliminary experimental analysis

Fragile X syndrome is the most common inherited cause of intellectual and developmental disability. The influence of environmental variables on behaviors associated with the syndrome has received only scant attention. The current study explored the function served by problem behavior in fragile X syndrome by using experimental functional analysis methodology with 8 children with fragile X. No child met criteria for attention-maintained problem behavior, 5 children met criteria for escape-maintained problem behavior, and 4 children met criteria for tangible-maintained problem behavior. Results are discussed and compared with previous findings on the function of problem behavior in fragile X syndrome, and implications for intervention are discussed. It is noted that the external validity of these findings is limited by the small sample size.

Neural correlates of task switching in paternal 15q11-q13 deletion Prader-Willi syndrome

We report a first study of brain activity linked to task switching in individuals with Prader-Willi syndrome (PWS). PWS individuals show a specific cognitive deficit in task switching which may be associated with the display of temper outbursts and repetitive questioning. The performance of participants with PWS and typically developing controls was matched in a cued task switching procedure, and brain activity was contrasted on switching and non-switching blocks using fMRI. Individuals with PWS did not show the typical frontal-parietal pattern of neural activity associated with switching blocks, with significantly reduced activation in regions of the posterior parietal and ventromedial prefrontal cortices. We suggest that this is linked to a difficulty in PWS in setting appropriate attentional weights to enable task-set reconfiguration. In addition to this, PWS individuals did not show the typical pattern of deactivation, with significantly less deactivation in an anterior region of the ventromedial prefrontal cortex. One plausible explanation for this is that individuals with PWS show dysfunction within the default mode network, which has been linked to attentional control. The data point to functional changes in the neural circuitry supporting task switching in PWS even when behavioural performance is matched to controls and thus highlight neural mechanisms that may be involved in a specific pathway between genes, cognition and behaviour.