Catherine Stewart

Heritability of Autism Spectrum Disorder in a UK Population-Based Twin Sample

IMPORTANCE Most evidence to date highlights the importance of genetic influences on the liability to autism and related traits. However, most of these findings are derived from clinically ascertained samples, possibly missing individuals with subtler manifestations, and obtained estimates may not be representative of the population. OBJECTIVES To establish the relative contributions of genetic and environmental factors in liability to autism spectrum disorder (ASD) and a broader autism phenotype in a large population-based twin sample and to ascertain the genetic/environmental relationship between dimensional trait measures and categorical diagnostic constructs of ASD. DESIGN, SETTING, AND PARTICIPANTS We used data from the population-based cohort Twins Early Development Study, which included all twin pairs born in England and Wales from January 1, 1994, through December 31, 1996. We performed joint continuous-ordinal liability threshold model fitting using the full information maximum likelihood method to estimate genetic and environmental parameters of covariance. Twin pairs underwent the following assessments: the Childhood Autism Spectrum Test (CAST) (6423 pairs; mean age, 7.9 years), the Development and Well-being Assessment (DAWBA) (359 pairs; mean age, 10.3 years), the Autism Diagnostic Observation Schedule (ADOS) (203 pairs; mean age, 13.2 years), the Autism Diagnostic Interview-Revised (ADI-R) (205 pairs; mean age, 13.2 years), and a best-estimate diagnosis (207 pairs). MAIN OUTCOMES AND MEASURES Participants underwent screening using a population-based measure of autistic traits (CAST assessment), structured diagnostic assessments (DAWBA, ADI-R, and ADOS), and a best-estimate diagnosis. RESULTS On all ASD measures, correlations among monozygotic twins (range, 0.77-0.99) were significantly higher than those for dizygotic twins (range, 0.22-0.65), giving heritability estimates of 56% to 95%. The covariance of CAST and ASD diagnostic status (DAWBA, ADOS and best-estimate diagnosis) was largely explained by additive genetic factors (76%-95%). For the ADI-R only, shared environmental influences were significant (30% [95% CI, 8%-47%]) but smaller than genetic influences (56% [95% CI, 37%-82%]). CONCLUSIONS AND RELEVANCE The liability to ASD and a more broadly defined high-level autism trait phenotype in this large population-based twin sample derives primarily from additive genetic and, to a lesser extent, nonshared environmental effects. The largely consistent results across different diagnostic tools suggest that the results are generalizable across multiple measures and assessment methods. Genetic factors underpinning individual differences in autismlike traits show considerable overlap with genetic influences on diagnosed ASD.

Family Therapy for Child and Adolescent Eating Disorders: A Critical Review

Eating disorder-focused family therapy has emerged as the strongest evidence-based treatment for adolescent anorexia nervosa, supported by evidence from nine RCTs, and there is increasing evidence of its efficacy in treating adolescent bulimia nervosa (three RCTs). There is also emerging evidence for the efficacy of multifamily therapy formats of this treatment, with a recent RCT demonstrating the benefits of this approach in the treatment of adolescent anorexia nervosa. In this article, we critically review the evidence for eating disorder-focused family therapy through the lens of a moderate common factors paradigm. From this perspective, this treatment is likely to be effective as it provides a supportive and nonblaming context that: one, creates a safe, predictable environment that helps to contain anxiety generated by the eating disorder; two, promotes specific change early on in treatment in eating disorder-related behaviors; and three, provides a vehicle for the mobilization of common factors such as hope and expectancy reinforced by the eating disorder expertise of the multidisciplinary team. In order to improve outcomes for young people, there is a need to develop an improved understanding of the moderators and mediators involved in this treatment approach. Such an understanding could lead to the refining of the therapy, and inform adaptations for those families who do not currently benefit from treatment.

Diagnosing Autism Spectrum Disorder in community settings using the development and well-being assessment: validation in a UK population-based twin sample

Background Increasing numbers of people are being referred for the assessment of autism spectrum disorder (ASD). The NICE (UK) and the American Academy of Pediatrics recommend gathering a developmental history using a tool that operationalises ICD/DSM criteria. However, the best‐established diagnostic interview instruments are time consuming, costly and rarely used outside national specialist centres. What is needed is a brief, cost‐effective measure validated in community settings. We tested the Development and Well‐Being Assessment (DAWBA) for diagnosing ASD in a sample of children/adolescents representative of those presenting in community mental health settings. Methods A general population sample of twins (TEDS) was screened and 276 adolescents were selected as at low (CAST score < 12; n = 164) or high risk for ASD (CAST score ≥ 15 and/or parent reported that ASD suspected/previously diagnosed; n = 112). Parents completed the ASD module of the DAWBA interview by telephone or online. Families were visited at home: the ADI‐R and autism diagnostic observation schedule (ADOS) were completed to allow a best‐estimate research diagnosis of ASD to be made. Results Development and Well‐Being Assessment ASD symptom scores correlated highly with ADI‐R algorithm scores (ρ = .82, p < .001). Good sensitivity (0.88) and specificity (0.85) were achieved using DAWBA computerised algorithms. Clinician review of responses to DAWBA questions minimally changed sensitivity (0.86) and specificity (0.87). Positive (0.82–0.95) and negative (0.90) predictive values were high. Eighty‐six per cent of children were correctly classified. Performance was improved by using it in conjunction with the ADOS. Conclusions The DAWBA is a brief structured interview that showed good sensitivity and specificity in this general population sample. It requires little training, is easy to administer (online or by interview) and diagnosis is aided by an algorithm. It holds promise as a tool for assisting with assessment in community settings and may help services implement the recommendations made by NICE and the American Academy of Pediatrics regarding diagnosis of young people on the autism spectrum.

Autism Spectrum Disorders and Other Mental Health Problems: Exploring Etiological Overlaps and Phenotypic Causal Associations

OBJECTIVE Recent studies have highlighted the impact of coexisting mental health problems in autism spectrum disorders (ASD). No twin studies to date have reported on individuals meeting diagnostic criteria of ASD. This twin study reports on the etiological overlap between the diagnosis of ASD and emotional symptoms, hyperactivity, and conduct problems measured with the Strengths and Difficulties Questionnaire. METHOD Genetic and environmental influences on the covariance between ASD and coexisting problems were estimated, in line with the correlated risks model prediction. Phenotypic causality models were also fitted to explore alternative explanations of comorbidity: namely, that coexisting problems are the result of or result in ASD symptoms; that they increase recognition of ASD; or that they arise due to an over-observation bias/confusion when differentiating between phenotypes. RESULTS More than 50% of twins with broad spectrum/ASD met the borderline/abnormal levels cut-off criteria for emotional symptoms or hyperactivity, and approximately 25% met these criteria for the 3 reported problems. In comparison, between 13% and 16% of unaffected twins scored above the cut-offs. The phenotypic correlation between ASD and emotional symptoms was explained entirely by genetic influences and accompanied by a moderate genetic correlation (0.42). The opposite was true for the overlap with conduct problems, as nonshared-environmental factors had the strongest impact. For hyperactivity, the best-fitting model suggested a unidirectional phenotypic influence of hyperactivity on ASD. CONCLUSION Our findings suggest a possible effect of hyperactivity on identification of ASD. The lack of genetic influences on conduct problems-ASD overlap further supports the genetic independence of these 2 phenotypes. Finally, the co-occurrence of emotional symptoms in ASD, compared to other co-occurring problems, is completely explained by common genetic effects.

Multi-Family Therapy for Bulimia Nervosa in Adolescence

Existing randomized controlled trials of family therapy for treatment of bulimia nervosa in adolescence highlight the need for further development of treatments. This article describes the development of multi-family treatment for bulimia nervosa in adolescents aged 13–18. It outlines the theory guiding this development, the areas of need identified by previous studies, and the treatment that has been designed to meet these needs. Particular attention is given to the need to increase communication between family members, strategies to reduce high levels of criticism or hostility, and skills to manage emotion dysregulation and low tolerance for negative emotions. To these ends the program draws on the multi-family treatment for anorexia nervosa, cognitive behavioral therapy techniques, and dialectical behavior therapy.

Impact of ASD Traits on Treatment Outcomes of Eating Disorders in Girls

Evidence links high levels of Autism Spectrum Disorder Traits in women with chronicity of anorexia nervosa. This study reports through clinical audit the impact of ASD traits on treatment outcomes of girls who were referred for treatment in a specialist eating disorder service. Presence of current, but not early childhood, ASD traits was elevated in comparison with previously reported community samples. Current ASD traits were correlated with emotional disorders and with need for treatment augmentation (psychiatric inpatient or day patient admission), but this relationship was not significant after the contribution of depression had been controlled for. There was no difference in Morgan Russell Outcomes at discharge for those with high and low current ASD traits. Parent-reported ASD-related developmental difficulties were associated with attenuated change in self-reported cognitive symptoms of AN. This study highlights the need for further understanding of the aetiology, diagnostic significance and predictive utility for future relapse of elevated ASD traits in childhood eating disorders. Copyright

Screening for co-occurring conditions in adults with autism spectrum disorder using the Strengths and Difficulties Questionnaire: a pilot study

Adolescents and adults with autism spectrum disorder (ASD) are at elevated risk of co‐occurring mental health problems. These are often undiagnosed, can cause significant impairment, and place a very high burden on family and carers. Detecting co‐occurring disorders is extremely important. However, there is no validated screening tool for this purpose. The aim of this pilot study is to test the utility of the strengths and difficulties questionnaire (SDQ) to screen for co‐occurring emotional disorders and hyperactivity in adolescents and adults with ASD. The SDQ was completed by 126 parents and 98 individuals with ASD (in 79 cases both parent and self‐report were available from the same families). Inter‐rater reliability, test‐retest stability, internal consistency, and construct validity were examined. SDQ subscales were also compared to clinically utilized measures of emotional disorders and hyperactivity to establish the ability to predict risk of disorder. Inter‐rater reliability (r = 0.42), test‐retest stability (r = 0.64), internal consistency (α = 0.52–0.81) and construct validity (r = 0.42–0.57) for the SDQ subscales were comparable to general population samples. Parent‐ and self‐report SDQ subscales were significantly associated with measures of anxiety, depression and hyperactivity (62–74% correctly classified). Parent‐report performed significantly better than self‐report; adults with ASD under‐reported difficulties. The SDQ shows promise as a simple and efficient way to screen for emotional disorders and hyperactivity in adolescents and adults with ASD that could help reduce the impact of these disorders on individuals and their families. However, further more systematic attempts at validation are warranted. Autism Res 2016, 9: 1353–1363.

Understanding the relationship between schematic beliefs, bullying, and unusual experiences in 8-14 year olds

BACKGROUND Cognitive models of adult psychosis propose that negative schematic beliefs (NSBs) mediate the established association between victimisation and psychotic symptoms. In childhood, unusual, or psychotic-like, experiences are associated with bullying (a common form of victimisation) and NSBs. This study tests the mediating role of NSBs in the relationship between bullying and distressing unusual experiences (UEDs) in childhood. METHOD Ninety-four 8-14 year olds referred to community Child and Adolescent Mental Health Services completed self-report assessments of UEDs, bullying, and NSBs about the self (NS) and others (NO). RESULTS Both NS and NO were associated with bullying (NS: r=.40, P<.001; NO: r=.33, P=.002), and with UEDs (NS: r=.51, P<.001; NO: r=.43, P<.001). Both NS and NO significantly mediated the relationship between bullying and UEDs (NS: z=3.15, P=.002; NO: z=2.35, P=.019). CONCLUSIONS Childrens NSBs may mediate the adverse psychological impact of victimisation, and are appropriate treatment targets for young people with UEDs. Early educational intervention to reduce negative appraisals of the self and others may increase resilience to future adverse experiences and reduce later mental health risk.

Intensive treatment program (ITP): A case series service evaluation of the effectiveness of day patient treatment for adolescents with a restrictive eating disorder

OBJECTIVE Family Therapy for Anorexia Nervosa (FT-AN) is the first line treatment for adolescents with anorexia nervosa in the UK. However, research suggests between 10 and 40% of young people have a poor outcome. For those for whom FT-AN alone is not effective there is a clear need to develop additional treatments. This paper describes the effectiveness of an additional treatment for adolescents who had not responded to FT-AN, the Intensive Day Treatment Program (ITP) embedded within a comprehensive outpatient service at the Maudsley Hospital. METHOD Data from a retrospective chart review of patient files were analyzed for 105 young people aged 11-18 with restrictive eating disorders referred to the program in the first four and a half years of its operation. RESULTS Young people attended ITP for only on average 28.41 days. Over this time they made significant improvements in a range of domains, including weight gain, eating disorder symptomatology, motivation to recover, quality of life and comorbid symptomatology. Young people continued to make improvements post ITP in outpatient treatment provided by the same service and 73.2% had a good or an intermediate outcome at the point of discharge from the service. DISCUSSION This uncontrolled case series indicates that ITP can contribute to positive outcomes for young people who require intensification of treatment. ITP outcomes are discussed in comparison to the published literature concerning day programs for adolescents with a diagnosis of an eating disorder.

Taste sensitivity in anorexia nervosa: A systematic review

Abstract Objective There is evidence for altered processing of taste in anorexia nervosa, particularly in the areas of reward processing and hedonic sensitivity. However, research on whether people with anorexia nervosa identify taste stimuli accurately, known as taste sensitivity, has yielded mixed findings. The objective of this study was to synthesize the literature on taste sensitivity in this disorder to provide a basis for future discussion on whether altered taste sensitivity may be also implicated in wider atypical taste processing in anorexia. Method Electronic databases were searched systematically to identify published research examining taste sensitivity in anorexia. Search terms were “anorexia nervosa”, or “eating disorder”, combined with “taste”. 18 studies met inclusion criteria. Results The review of the findings suggest that individuals with AN may experience reduced taste sensitivity that may improve following recovery. However, there was a significant variability in results across studies, potentially reflecting methodological problems including low sample sizes, experimental designs, and uncontrolled confounding variables. Discussion: This review suggests that altered taste sensitivity could represent a component in the wider altered taste processing observed in anorexia nervosa. However, the heterogeneity of findings highlight the need for future research to consider methodological issues raised by this review.