Efficacy of cannabinoids in neurodevelopmental and neuropsychiatric disorders among children and adolescents: a systematic review.

A better understanding of the endocannabinoid system and a relaxation in regulatory control of cannabis globally has increased interest in the medicinal use of cannabinoid-based products (CBP). We provide a systematic review of the rationale and current clinical trial evidence for CBP in the treatment of neuropsychiatric and neurodevelopmental disorders in children and adolescents. A systematic search of MEDLINE, Embase, PsycINFO, and the Cochrane Central Register of Trials was performed to identify articles published after 1980 about CBP for medical purposes in individuals aged 18 years or younger with selected neuropsychiatric or neurodevelopmental conditions. Risk of bias and quality of evidence was assessed for each article. Of 4466 articles screened, 18 were eligible for inclusion, addressing eight conditions (anxiety disorders (n = 1); autism spectrum disorder (n = 5); foetal alcohol spectrum disorder (n = 1); fragile X syndrome (n = 2); intellectual disability (n = 1); mood disorders (n = 2); post-traumatic stress disorder (n = 3); and Tourette syndrome (n = 3)). Only one randomised controlled trial (RCT) was identified. The remaining seventeen articles included one open-label trial, three uncontrolled before-and-after trials, two case series and 11 case reports, thus the risk of bias was high. Despite growing community and scientific interest, our systematic review identified limited and generally poor-quality evidence for the efficacy of CBP in neuropsychiatric and neurodevelopmental disorders in children and adolescents. Large rigorous RCTs are required to inform clinical care. In the meantime, clinicians must balance patient expectations with the limited evidence available.

The characteristics of temper outbursts in Prader-Willi syndrome.

The purpose of this study was to develop a comprehensive understanding of temper outbursts in Prader-Willi syndrome (PWS). A survey was developed from interviews conducted with individuals with PWS and their caregivers. The survey was completed by 101 primary caregivers. The findings suggest that outburst frequency decreases with age while duration increases. Adolescents exhibited more severe behaviors than children or adults. No differences were found across gender or genetic subtype. Provocations fit into three themes: goal blockage, social injustice, and difficulty dealing with change. Distracting the person or giving them space to calm down were the only management strategies judged effective. Risperidone, sertraline, and fluoxetine were the most common medications prescribed for outbursts, though parents reported only minor effects.

Microstructural white matter tract alteration in Prader-Willi syndrome: A diffusion tensor imaging study.

Prader-Willi Syndrome (PWS) is a genetic disorder characterized by infantile hypotonia, hyperphagia, hypogonadism, growth hormone deficiency, intellectual disability, and severe emotional and behavioral problems. The brain mechanisms that underpin these disturbances are unknown. Diffusion tensor imaging (DTI) enables in vivo investigation of the microstructural integrity of white matter pathways. To date, only one study has used DTI to examine white matter alterations in PWS. However, that study used selected regions of interest, rather than a whole brain analysis. In the present study, we used diffusion tensor and magnetic resonance (T 1-weighted) imaging to examine microstructural white matter changes in 15 individuals with PWS (17-30 years) and 15 age-and-gender-matched controls. Whole-brain voxel-wise statistical analysis of FA was carried out using tract-based spatial statistics (TBSS). Significantly decreased fractional anisotropy was found localized to the left hemisphere in individuals with PWS within the splenium of the corpus callosum, the internal capsule including the posterior thalamic radiation and the inferior frontal occipital fasciculus (IFOF). Reduced integrity of these white matter pathways in individuals with PWS may relate to orientating attention, emotion recognition, semantic processing, and sensorimotor dysfunction.

Reduced gamma-aminobutyric acid is associated with emotional and behavioral problems in Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is characterized by infantile hypotonia, hypogonadism, small hands and feet, distinct facial features and usually intellectual impairment. The disorder is associated with severe behavioral disturbances which include hyperphagia leading to morbid obesity, temper outbursts, skin-picking, and compulsive behaviors. While the brain mechanisms that underpin these disturbances are unknown these behaviors suggest a lack of inhibition and thus gamma-aminobutyric acid (GABA), the main inhibitory neurotransmitter may be implicated. In the present study, we investigated in vivo brain GABA and its relationship with emotion and behavior in individuals with PWS. Single voxel proton magnetic resonance spectroscopy (1H-MRS) was performed on 15 individuals with PWS and 15 age- and gender-matched typically developing controls. GABA levels were measured in the parieto-occipital lobe. All other metabolite levels (N-acetyl aspartate, myo-Inositol, glutathione, glutamate, and glutamine + glutamate) were measured in the anterior cingulate cortex (ACC). GABA levels were significantly lower in the participants with PWS who had clinically significant emotional and behavioral problems relative to typically developing control participants and participants with PWS who did not have emotional and behavioral problems within the clinically significant range. GABA levels were negatively correlated with total behavioral problem scores as well as temper outbursts, skin-picking, depression, social relating difficulties, and a tendency to be self-absorbed. Our data suggests that alterations of the GABAergic system may play an important role in aspects of the pathophysiology of PWS. Pathological mechanism found in PWS may be relevant to understanding the control of similar behaviors in the general population. © 2016 Wiley Periodicals, Inc.

The developmental trajectory of disruptive behavior in Down syndrome, fragile X syndrome, Prader-Willi syndrome and Williams syndrome.

The aim of this study was to investigate the developmental trajectories of verbal aggression, physical aggression, and temper tantrums in four genetic syndrome groups. Participants were part of the Australian Child to Adult Development Study (ACAD), which collected information from a cohort of individuals with an intellectual disability at five time points over 18 years. Data were examined from a total of 248 people with one of the four following syndromes: Down syndrome, Fragile X syndrome, Prader-Willi syndrome, or Williams syndrome. Changes in behaviors were measured using validated items from the Developmental Behavior Checklist (DBC). The results indicate that, while verbal aggression shows no evidence of diminishing with age, physical aggression, and temper tantrums decline with age before 19 years for people with Down syndrome, Fragile X syndrome, and William syndrome; and after 19 years for people with Prader-Willi syndrome. These findings offer a somewhat more optimistic outlook for people with an intellectual disability than has previously been suggested. Research is needed to investigate the mechanisms predisposing people with PWS to persistence of temper tantrums and physical aggression into adulthood.

The effects of a course of intranasal oxytocin on social behaviors in youth diagnosed with autism spectrum disorders: a randomized controlled trial.

BACKGROUND: There is increasing interest in oxytocin as a therapeutic to treat social deficits in autism spectrum disorders (ASD). The aim of this study was to investigate the efficacy of a course of oxytocin nasal spray to improve social behavior in youth with ASD. METHODS: In a double-blind, placebo-controlled trial across two Australian university sites between February 2009 and January 2012, 50 male participants aged between 12 and 18 years, with Autistic or Asperger's Disorder, were randomized to receive either oxytocin (n = 26) or placebo (n = 24) nasal sprays (either 18 or 24 International Units), administered twice-daily for 8 weeks. Participants were assessed at baseline, after 4- and 8-weeks of treatment, and at 3-month follow-up. Primary outcomes were change in total scores on the caregiver-completed Social Responsiveness Scale and clinician-ratings on the Clinical Global Impressions-Improvement scale. Secondary assessments included caregiver reports of repetitive and other developmental behaviors and social cognition. CLINICAL TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry www.anzctr.org.au ACTRN12609000513213. RESULTS: Participants who received oxytocin showed no benefit following treatment on primary or secondary outcomes. However, caregivers who believed their children received oxytocin reported greater improvements compared to caregivers who believed their child received placebo. Nasal sprays were well tolerated and there was no evidence of increased side effects resulting from oxytocin administration. CONCLUSIONS: This is the first evaluation of the efficacy for a course of oxytocin treatment for youth with ASD. Although results did not suggest clinical efficacy, further research is needed to explore alternative delivery methods, earlier age of intervention, and the influence of caregiver expectation on treatment response.

A double-blind randomized controlled trial of oxytocin nasal spray in Prader Willi syndrome.

Individuals with Prader-Willi syndrome (PWS) have a significant reduction in the number of oxytocin-producing neurons (42%) in the hypothalamic paraventricular nucleus. A number of animal studies and observations of humans show that lesions in this region can produce PWS-like symptoms. Given the evidence for potential oxytocin deficiency, we tested the effects of a course of intranasal oxytocin on PWS symptoms. Thirty individuals with PWS aged 12-30 years participated in an 18-week randomized double-blind placebo-controlled crossover trial. Participants received 8 weeks of oxytocin and 8 weeks of placebo with a minimum 2-week washout period. The first 11 participants received the following oxytocin doses: 24 IU (twice daily) B.I.D for participants 16 years and over and 18 IU B.I.D for participants 13-15 years. The dose was increased for the remaining 18 participants to 40 IU B.I.D for participants 16 years and over and 32 IU B.I.D for 13-15 years. Measures used to assess changes were standardized well-accepted measures, including the Developmental Behavior Checklist-Monitor, Parent, Teacher, and Adult; The Yale-Brown Obsessive Compulsive Scale; The Dykens Hyperphagia questionnaire; Reading The Mind in the Eyes Test; Epworth Sleepiness Scale and the Movie Stills. Oxytocin had little impact on any measure. The only significant difference found between the baseline, oxytocin, and placebo measures was an increase in temper outbursts (P = 0.023) with higher dose oxytocin. The lack of effect of oxytocin nasal spray may reflect the importance of endogenous release of oxytocin in response to exogenous oxytocin.

The relationship between cardiac activity, behaviour and endogenous oxytocin and vasopressin in Prader-Willi Syndrome: An exploratory study.

This study aimed to increase our understanding of cardiac activity abnormalities in Prader-Willi Syndrome (PWS) and the relationship between cardiac activity, PWS behaviours thought to be associated with cardiac vagal tone and endogenous oxytocin and vasopressin levels. We compared cardiac activity (respiratory sinus arrhythmia (RSA), low-frequency heart rate variability (LF-HRV), heart period) in 30 adolescents and adults with PWS to 30 typically developing age-matched controls. RSA, LF-HRV, and heart period were lower in individuals with PWS than in the control group. In the control group, RSA was higher for females than males. However, for those with PWS, there was no difference between the sexes. Individuals with the mUPD genetic subtype had lower RSA and LF-HRV than participants with the PWS deletion subtype and compared to typically developing controls, no difference was found between the latter two groups. Heart period was also lower for those with mUPD compared to controls. Higher RSA reduced the odds of having temper outbursts and skin-picking. RSA was lower in those with PWS and psychosis compared to those with PWS without psychosis. Finally, we found RSA correlated with vasopressin for those with mUPD but not deletion. There was no relationship between RSA and oxytocin plasma or saliva levels. Our findings suggest autonomic dysfunction in PWS that is more marked in mUPD than deletion and potentially due to greater loss of parasympathetic activity in mUPD.

The relationship between endogenous oxytocin and vasopressin levels and the Prader-Willi syndrome behaviour phenotype.

Background: Oxytocin and vasopressin systems are altered in Prader Willi syndrome (PWS). However, investigations into endogenous oxytocin and vasopressin levels as well as clinical trials evaluating the effect of exogenous oxytocin on PWS symptoms have had mixed results. It is also unknown whether endogenous oxytocin and vasopressin levels are associated with certain PWS behaviours. Method: We compared plasma oxytocin and vasopressin and saliva oxytocin levels in 30 adolescents and adults with PWS to 30 typically developing age-matched controls. We also compared neuropeptide levels between gender and genetic subtypes within the PWS cohort and examined the relationship between neuropeptide levels and PWS behaviours. Results: While we did not measure a group difference in plasma or saliva oxytocin levels, plasma vasopressin was significantly lower in individuals with PWS compared to controls. Within the PWS cohort, saliva oxytocin levels were higher in females compared to males and individuals with the mUPD compared to the deletion genetic subtype. We also found the neuropeptides correlated with different PWS behaviours for males and females and for genetic subtypes. For the deletion group, higher plasma and saliva oxytocin levels were related to fewer behaviour problems. For the mUPD group, higher plasma vasopressin levels were related to more behaviour problems. Conclusion: These findings support existing evidence of a vasopressin system defect in PWS and for the first time identify potential differences in the oxytocin and vasopressin systems across PWS genetic subtypes.

The availability of normative data for the Developmental Behaviour Checklist for Adults.

BACKGROUND: Standardised normative data for checklists of behavioural and emotional disturbance have a demonstrated usefulness for clinicians, researchers, and service providers. METHOD: The Developmental Behaviour Checklist for Adults (DBC-A) was the instrument used in a large-scale Australian study (n = 1,538) of emotional and behavioural disturbance. RESULTS: To assist the field, normative data is now available on the DBC-A for adults with ID from age 18-85 years, across three levels of intellectual disability (ID). A condensed version of DBC-A normative data is presented here. CONCLUSIONS: A large population-based study provided an opportunity for further checklist development, and the utility of the DBC-A has been enhanced by the provision of normative data.

How much does intellectual disability really cost? First estimates for Australia.

BACKGROUND: Given the paucity of relevant data, this study estimates the cost of intellectual disability (ID) to families and the government in Australia. METHOD: Family costs were collected via the Client Service Receipt Inventory, recording information relating to service use and personal expense as a consequence of ID. Government expenditure on the provision of support and services was estimated using top-down costing. RESULTS: A total of 109 parents participated. The cost of ID in Australia is high, especially for families. Total economic costs of ID are close to $14,720 billion annually. Opportunity cost of lost time provided 85% of family expense. A comparison of family expense and social welfare benefits received suggests that families suffer considerable loss. This may impact on families' physical and emotional wellbeing. CONCLUSIONS: Monitoring of changes in expenditure is required. Policies should ensure that money devoted to ID is allocated in a rational, equitable, and cost-effective manner.

Context influences the motivation for stereotypic and repetitive behaviour in children diagnosed with intellectual disability with and without autism.

BACKGROUND: Children are motivated to engage in stereotypic and repetitive behaviours for a number of reasons. Their motivation seems to change according to context, but little empirical evidence supports that observation. Interventions designed to reduce the behaviours may be improved by an increased understanding of the interaction between motivation and context. METHOD: Using Rasch analysis, we analysed data describing stereotypic behaviours from 279 Revised Motivation Assessment Scales (MAS:R). Data were gathered from two groups of children: Group 1 with intellectual disability (n = 37) and Group 2 with both intellectual disability and autism (n = 37). We examined behaviours in three contexts: free time, transition and while engaged in tasks. MAS:R distinguishes two intrinsic motivators: enhanced sensation and decreased anxiety and three extrinsic motivators: seeking attention or objects or escape. RESULTS: Significant differences in motivators were observed during free time and transition. No one motivator predominated while children were engaged in tasks. For both groups, sensory enhancement was a more likely motivator in free time and anxiety reduction was a more likely motivator during transition. Transition was the context most likely to influence extrinsic motivators, but there were significant differences between the groups. CONCLUSIONS: Context influences the motivation for stereotyped and repetitive behaviours. Transition has a particularly powerful effect.

Interventions provided by parents for children with intellectual disabilities in low and middle income countries.

BACKGROUND: In low- and middle-income (LAMI) countries, there is a lack of well-trained therapists to provide specialist interventions for children with intellectual disabilities and their families. We sought to identify strategies deliverable by families or non-specialist workers. MATERIALS AND METHODS: After searches of appropriate scientific databases, we applied GRADE methodology to rate the quality of evidence for these interventions. RESULTS: We identified small-scale interventions trialled in LAMI countries with limited evidence of effectiveness in supporting development, adaptive behaviour and/or community participation. In high-income countries, the Stepping Stones Triple P program for adaptive behaviour and the Portage program for child development have the most extensive evidence base and may be applicable in LAMI countries. CONCLUSIONS: There is reason to hope that, when combined with community development strategies, the welfare of children with intellectual disabilities in LAMI countries can be advanced within those countries' economic means.

Comorbidity of intellectual disability and mental disorder in children and adolescents: a systematic review.

BACKGROUND: Mental disorder and intellectual disability each accounts for substantial burden of disease. However, the extent of this co-occurrence varies substantially between reports. We sought to determine whether studies in children and/or adolescents with acceptably rigorous methods can be distinguished from existing reports, and whether key risk factors could be ascertained. METHOD: Published studies investigating the prevalence of mental disorders in children and/or adolescents with intellectual disability were reviewed. RESULTS: Nine studies with acceptable methods were identified, 4 which compared the prevalence of mental disorder in populations of those with and without intellectual disability, and a further 5 studies that estimated the rates of mental disorder in those with intellectual disability were identified. Collectively, these studies demonstrate rates of comorbidity for children and adolescents between 30 and 50% with a relative risk of mental disorder associated with intellectual disability ranging from 2.8-4.5. The risks for this comorbidity associated with age, gender, severity of intellectual disability, and socioeconomic status remain uncertain. CONCLUSIONS: Appreciation of this comorbidity needs to be a fundamental component of both mental health and intellectual disability services.

Extracting more information from behaviour checklists by using components of mean based scores.

Sums of responses to behaviour checklist items are commonly used as outcome measures. We argue for the use of mean scores. For sets of responses registering absence and presence at different levels of intensity of behaviours we also show that mean scores may usefully be 'decomposed' into separate measures of the range and the intensity of problematic behaviours. These separate measures are the proportion of items positively endorsed and the 'intensity index' - the proportion of positive scores that are above one. We illustrate their use with primary outcome scores from the Developmental Behaviour Checklist (DBC) in the Australian Child to Adult Development Study. The low mean scores of young people with profound intellectual disability are shown to be a function of the narrow range of behaviours they display rather than of the level of intensity of these behaviours, which is relatively high. Change over time in mean scores is shown to be attributable to change in both the range and the intensity of behaviours as young people age in the study. We show how the technique of measuring these two separate strands contributing to mean scores may be applied to checklists with sets of responses longer than the zero, one, two of the DBC.

A review of clinical trials of oxytocin in Prader-Willi syndrome.

PURPOSE OF REVIEW: PWS is a severe developmental disability for which there is no known treatment. The oxytocin system is currently a primary target for intervention. The aim of this article is to review the evidence for the efficacy of intranasal oxytocin in PWS. RECENT FINDINGS: To date, there have been five clinical trials of oxytocin in PWS. Four of these studies reported that oxytocin improved behaviors. However, each of these studies suffered important limitations that likely influenced the findings. For example, one study did not include a control group. Another study did not statistically analyze the effects of oxytocin on behavior. The final two studies used study-specific measures for which psychometric properties have not been assessed. SUMMARY: Because of these limitations, the most appropriate conclusion to draw from the existing studies is that there is currently no convincing evidence that intranasal oxytocin improves symptoms of PWS. However, this does not mean that oxytocin is not involved in PWS. Rather, it suggests that further work is needed to understand the nature of the PWS oxytocin abnormality.

Short form of the developmental behaviour checklist.

A 24-item short form of the 96-item Developmental Behaviour Checklist was developed to provide a brief measure of Total Behaviour Problem Score for research purposes. The short form Developmental Behaviour Checklist (DBC-P24) was chosen for low bias and high precision from among 100 randomly selected item sets. The DBC-P24 was developed from epidemiological data in the first three waves of the Australian Child to Adult Development study, and cross validated for groups with autism, fragile X, Prader-Willi, and Williams in this longitudinal study and in cross sectional Dutch, English, and Finnish samples of young people with intellectual disability. The DBC-P24 has low bias and high precision in cross-validation samples and achieves high sensitivity and specificity to full DBC-P based caseness decisions.

A cross-cultural exploration of the everyday social participation of individuals with autism spectrum disorders in Australia and Taiwan: An experience sampling study.

Individuals with an autism spectrum disorder commonly have limited social participation. This study aimed to examine the similarities and differences of everyday participation among males and females with autism spectrum disorder in Australia and Taiwan, using an experience sampling methodology. A total of 14 Australians (4 males, aged 16-43 years) and 16 Taiwanese (12 males, aged 19-45 years) with autism spectrum disorder who are cognitively able were asked to carry a device which prompted them seven times per day for 7 days, to record everyday participation: where they were, what they were doing, and who they were with. Multilevel analyses were used to identify the relationships between everyday participation and associated factors including gender, country of residence, clinical severity of autism spectrum disorder, and social anxiety. The results showed that Taiwanese participants were more likely to stay at home than Australian participants. However, female participants were more likely to engage in social situations than males. Furthermore, participants with fewer autism spectrum disorder symptoms and those with higher levels of social anxiety were less likely to engage in social interactions. This study sheds light on ways that culture and gender affect social participation and highlights the relationship of social anxiety to social participation. The findings have implications for interventions for social participation.

Psychopathology in children and adolescents with autism compared to young people with intellectual disability.

Autism is a neurodevelopmental disorder with a specific pattern of behavioural, communication and social problems. Additional mental health problems are often poorly understood and undetected. This study investigates the level and pattern of emotional and behavioural problems in young people with autism compared with children with intellectual disability (ID). Subjects were 381 young people with autism and a representative group of 581 Australian young people with ID aged 4-18 years. Parents/carers provided details of the emotional and behavioural problems of their child using the Developmental Behaviour Checklist (DBC-P). Young people with autism were found to suffer from significantly higher levels of psychopathology than young people with ID. The implications of this finding are discussed.

Mortality in Prader-Willi syndrome.

Persons with Prader-Willi syndrome have been known to have a high mortality rate. However, intellectual disability, which usually accompanies Prader-Willi syndrome, is also associated with a higher mortality rate than in the general population. In this study, the death rates in a longitudinal cohort of people with Prader-Willi syndrome are compared with those for an epidemiologically derived control sample of people with intellectual disability from other causes. We found that those with Prader-Willi syndrome had a higher mortality rate than did controls. After the protective effect of mild intellectual disability or average intellectual function was accounted for, the hazard ratio for Prader-Willi syndrome versus controls was 6.07. Obesity and its complications were factors contributing to the mortality identified in this study.