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

Accuracy of paper-and-pencil systematic observation versus computer-aided systems

Computer-aided behavior observation is gradually supplanting paper-and-pencil approaches to behavior observation, but there is a dearth of evidence on the relative accuracy of paper-and-pencil versus computer-aided behavior observation formats in the literature. The current study evaluated the accuracy resulting from paper-and-pencil observation and from two computer-aided behavior observation methods: The Observer XT® desktop software and the Big Eye Observer® smartphone application. Twelve postgraduate students without behavior observation experience underwent a behavior observation training protocol. As part of a multi-element design, participants recorded 60 real clinical sessions randomly assigned to one of the three observation methods. All three methods produced high levels of accuracy (paper-and-pencil, .88 ± .01; The Observer XT, .84 ± .01; Big Eye Observer, .84 ± .01). A mixed linear model analysis indicated that paper-and-pencil observation produced marginally superior accuracy values, whereas the accuracy produced by The Observer XT and Big Eye Observer did not differ. The analysis suggests that accuracy of recording was mediated by the number of recordable events in the observation videos. The implications of these findings for research and practice are discussed.

Conducting In-Home Functional Analyses of Aggression and Self-Injury Exhibited by Boys with Fragile X Syndrome

OBJECTIVE

Boys with fragile X syndrome (FXS) are at increased risk for exhibiting aggression and self-injury that can be extremely disruptive to families. Few studies, however, have examined the extent to which social-environmental factors can influence these behaviors, particularly in home settings.

METHODS

Caregivers of 32 boys with FXS, aged 3 to 10 years, were coached by a board-certified behavior analyst to implement a functional analysis (FA) with their child in their home over 2 days. The functions identified in the FAs were validated by behavioral interventions conducted through telehealth over 12 weeks.

RESULTS

Social functions for aggression and self-injury were identified in 29 (90.6%) cases, with the most common functions identified being escape from demands/transitions and/or tangible reinforcement. Subsequent function-based behavioral interventions (i.e., functional communication training) implemented for 22 cases by telehealth resulted in decreased rates of aggression and self-injury by 74% to 100%.

CONCLUSION

These data underscore the significant impact that social-environmental factors can have on the development and maintenance of aggression and self-injury in FXS. Conducting early home-based behavioral interventions designed to increase functional communication skills may therefore be an effective solution for the treatment of aggression and self-injury in FXS in the long term.

The RDoC approach for translational psychiatry: Could a genetic disorder with psychiatric symptoms help fill the matrix? the example of Prader-Willi syndrome

The Research Domain Criteria project (RDoc) proposes a new classification system based on information from several fields in order to encourage translational perspectives. Nevertheless, integrating genetic markers into this classification has remained difficult because of the lack of powerful associations between targeted genes and RDoC domains. We hypothesized that genetic diseases with psychiatric manifestations would be good models for RDoC gene investigations and would thereby extend the translational approach to involve targeted gene pathways. To explore this possibility, we reviewed the current knowledge on Prader-Willi syndrome, a genetic disorder caused by the absence of expression of some of the genes of the chromosome 15q11-13 region inherited from the father. Indeed, we found that the associations between genes of the PW locus and the modification identified in the relevant behavioral, physiological, and brain imaging studies followed the structure of the RDoC matrix and its six domains (positive valence, negative valence, social processing, cognitive systems, arousal/regulatory systems, and sensorimotor systems).

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.

Injury characteristics across functional classes of self-injurious behavior

Self-injurious behavior (SIB) is inherently problematic because it can lead to injuries, including those that are quite severe and may result in loss of function or permanent disfigurement. The current study replicated and extended Rooker et al. (2018) by classifying the physical characteristics of injuries across groups of individuals with automatically maintained SIB (ASIB Subtypes 2 and 3) and socially maintained SIB. Individuals with Subtype 2 ASIB had the most frequent and severe injuries. Further, an inverse relation was found between the level of differentiation in the functional analysis and the number of injuries across groups. Studying the response products of SIB (the injuries) documents the risks associated with SIB, justifies the need for research and the intensive intervention, and advances knowledge of SIB. Additional research is needed to replicate these findings, and determine the variables that produce different characteristics of injury secondary to SIB.

Classification of injuries observed in functional classes of self-injurious behaviour

BACKGROUND

Limited research has examined how the functions of self-injurious behaviour (SIB) relate to the production of injuries and the location, type or severity of those injuries.

METHODS

Clinical and medical records were coded for 64 individuals hospitalised for SIB. When injuries were present, the physical properties of SIB and injuries were assessed across groups of individuals with automatically and socially maintained SIB.

RESULTS

Injuries were observed for 35 of the individuals who engaged in SIB. Individuals who engaged in a single form of SIB were more likely to have injuries (P < .05). Individuals with SIB maintained by automatic reinforcement had significantly more severe injuries to the head than those in the social group (q < .05, P = .0132, H = 12.54).

CONCLUSION

Although results are preliminary, the results provide evidence that the function of SIB may influence the severity and location of injuries produced.

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.

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.

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.

Functional analysis and treatment of problem behavior exhibited by children with fragile X syndrome

The efficacy of function-based interventions for the treatment of severe problem behavior exhibited by individuals with intellectual and developmental disabilities (IDD) is well established. However, few studies have reported on behavioral interventions in fragile X syndrome (FXS) specifically. The present study is a consecutive case-series analysis that reports on functional analysis and treatment of problem behavior of nine children with FXS. Assessment findings were consistent with previous research indicating that among individuals with FXS, problem behavior is more commonly maintained by escape from demands and access to tangible items, relative to the broader population of individuals with IDD. Functional analysis-based behavioral interventions resulted in a mean reduction in problem behavior of 95.2% across the nine participants. Additionally, generalization of treatment effects from controlled clinical settings to home, school, and community was demonstrated. The current findings suggest that function-based behavioral interventions shown to be effective with the broader population of individuals with IDD are also effective for individuals with FXS. Our results in combination with those of previous studies describing functional analysis outcomes provide additional evidence for a unique functional behavioral phenotype for severe problem behavior in individuals with FXS. Implications of study findings for early intervention and prevention of problem behavior in children with FXS are discussed.

Neural correlates of self-injurious behavior in Prader-Willi syndrome

Individuals with Prader-Willi syndrome (PWS), a genetic disorder caused by mutations to the q11-13 region on chromosome 15, commonly show severe skin-picking behaviors that can cause open wounds and sores on the body. To our knowledge, however, no studies have examined the potential neural mechanisms underlying these behaviors. Seventeen individuals with PWS, aged 6-25 years, who showed severe skin-picking behaviors, were recruited and scanned on a 3T scanner. We used functional magnetic resonance imaging (fMRI) while episodes of skin picking were recorded on an MRI-safe video camera. Three participants displayed skin picking continuously throughout the scan, three participants did not display skin picking, and the data for one participant evidenced significant B0 inhomogeneity that could not be corrected. The data for the remaining 10 participants (six male, four female) who displayed a sufficient number of picking and nonpicking episodes were subjected to fMRI analysis. Results showed that regions involved in interoceptive, motor, attention, and somatosensory processing were activated during episodes of skin-picking behavior compared with nonpicking episodes. Scores obtained on the Self-Injury Trauma scale were significantly negatively correlated with mean activation within the right insula and left precentral gyrus. These data indicate that itch and pain processes appear to underlie skin-picking behaviors in PWS, suggesting that interoceptive disturbance may contribute to the severity and maintenance of abnormal skin-picking behaviors in PWS. Implications for treatments are discussed.

Cognitive and behavioural aspects of Prader-Willi syndrome

PURPOSE OF REVIEW

To provide a review of the recent advances in the diagnosis and treatment of psychiatric disorders in Prader-Willi syndrome (PWS).

RECENT FINDINGS

Research in the last 12 months has provided a descriptive prognosis of psychosis in PWS and highlighted the possible genes associated with the increased risk of psychosis for those with maternal uniparental disomy (mUPD). Several studies investigating social and communication skills have shown people with PWS to have difficulty with core, receptive and expressive language skills, interpreting emotional valence in faces, playing with children of their own age, understanding personal space and a developmental delay in the theory of mind. These social and communication deficits are often more pronounced in those with mUPD. Two recent clinical trials of oxytocin provide mixed results and highlight the need for an improved understanding of the neurobiological characteristics of the PWS brain. A recent pilot study suggests N-acetylcysteine may be a viable treatment for skin picking.

SUMMARY

Recent advances have contributed to our understanding of the emotional and behavioural problems associated with PWS, and provided directions for further research.