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Evidence indicates that autism spectrum disorder (ASD) is underidentified in populations with psychosis, but that clinical presentations of comorbid ASD and psychosis (ASD-P) and specific treatment needs that may relate to this group are not well understood. In fact, recent studies of ASD in first-episode psychosis suggest that there may be a specific clinical presentation of ASD-P. In response, the Cambridgeshire and Peterborough Early Intervention in Psychosis (EIP) service in the UK implemented and evaluated a 3-step ASD screening and diagnostic protocol, using the Autism Spectrum Disorder in Adults Screening Questionnaire (ASDASQ), case note review, and the Autism Diagnostic Observation Schedule (ADOS-2) and the Childhood Autism Spectrum Test (CAST). As a quality improvement project, the evaluation aimed to (1) establish the prevalence of patients with ASD-P, (2) describe characteristics of the clinical presentation of ASD-P and compare them to those of patients suffering from psychosis but no ASD, and (3) determine any differences in treatment between psychosis patients with and without ASD. Notably, at least 9% of the EIP service caseload met the criteria for a diagnosis of ASD-P, with half identified via the implementation of this protocol. The patients with ASD-P had specific clinical presentations and treatment needs that differed from those of patients with psychosis but no ASD. Thus, the findings from this study supported existing evidence concerning the underdetection of ASD in EIP populations. Our findings also added to emerging evidence for a clinical presentation of ASD-P with specific treatment needs. Our protocol has now been established as routine practice, and its implementation has improved the detection and treatment of patients with ASD-P within our EIP service.

ObjectiveThis is a prospective population screening study for autism in toddlers aged 18–30 months old using the Quantitative Checklist for Autism in Toddlers (Q-CHAT), with follow-up at age 4.DesignObservational study.SettingLuton, Bedfordshire and Cambridgeshire in the UK.Participants13 070 toddlers registered on the Child Health Surveillance Database between March 2008 and April 2009, with follow-up at age 4; 3770 (29%) were screened for autism at 18–30 months using the Q-CHAT and the Childhood Autism Spectrum Test (CAST) at follow-up at age 4.InterventionsA stratified sample across the Q-CHAT score distribution was invited for diagnostic assessment (phase 1). The 4-year follow-up included the CAST and the Checklist for Referral (CFR). All with CAST ≥15, phase 1 diagnostic assessment or with developmental concerns on the CFR were invited for diagnostic assessment (phase 2). Standardised diagnostic assessment at both time-points was conducted to establish the test accuracy of the Q-CHAT.Main outcome measuresConsensus diagnostic outcome at phase 1 and phase 2.ResultsAt phase 1, 3770 Q-CHATs were returned (29% response) and 121 undertook diagnostic assessment, of whom 11 met the criteria for autism. All 11 screened positive on the Q-CHAT. The positive predictive value (PPV) at a cut-point of 39 was 17% (95% CI 8% to 31%). At phase 2, 2005 of 3472 CASTs and CFRs were returned (58% response). 159 underwent diagnostic assessment, including 82 assessed in phase 1. All children meeting the criteria for autism identified via the Q-CHAT at phase 1 also met the criteria at phase 2. The PPV was 28% (95% CI 15% to 46%) after phase 1 and phase 2.ConclusionsThe Q-CHAT can be used at 18–30 months to identify autism and enable accelerated referral for diagnostic assessment. The low PPV suggests that for every true positive there would, however, be ~4–5 false positives. At follow-up, new cases were identified, illustrating the need for continued surveillance and rescreening at multiple time-points using developmentally sensitive instruments. Not all children who later receive a diagnosis of autism are detectable during the toddler period.

Objective Attention deficit/hyperactivity disorder (ADHD) is a developmental disorder caused by structural and functional brain abnormalities as well as genetic and environmental factors. ADHD symptoms are commonly observed in individuals with epilepsy. A few studies have reported a pattern of behavioral problems in children with combined epilepsy and ADHD. We aimed to evaluate comorbid behavioral problems and mental health concerns among children with epilepsy with ADHD and without ADHD including autism spectrum disorder, anxiety, depression, somatic problems, oppositional defiant disorder, and conduct disorder. Methods A total of 100 children aged between 6 and 11 years were recruited and categorized into 1 of 5 groups (20 child/group): (1) epilepsy, (2) epilepsy with ADHD, (3) ADHD with electroencephalogram (EEG) changes, (4) ADHD without EEG changes, and (5) healthy control. The scales used in our study included the Childhood Autism Spectrum Test (CAST) to screen autism spectrum conditions and related social and communication conditions, Conners’ Parent Rating Scale (CPRS) to assess ADHD and other comorbid behavioral and social-emotional difficulties, and Children Behavior Checklist (CBCL) to evaluate behavior problems. Results The CAST scale score showed no significant difference among the studied groups. Regarding the Conners-3 scale, the combined type of ADHD was predominant in the ADHD with EEG changes group and the ADHD with epilepsy group, while hyperactive ADHD was predominant in the ADHD without EEG changes group. The ADHD with EEG changes group and the ADHD with epilepsy group had equally high clinical rating scores for CBCL in internalizing and externalizing problems. There was a significant difference in the profile of all Diagnostic and Statistical Manual of Mental Disorders (DSM-5) scales of CBCL among the studied groups. Conclusion This is the first study to use EEG in patients with ADHD in comparison with epilepsy. ADHD with epilepsy is closely related to ADHD with EEG changes regarding psychiatric comorbidity in terms of anxiety, depression, somatic problems, oppositional defiance problems, and conduct problems.

In developing countries, autism is needed to detect at early ages that helps us to improve the conditions of children. The diagnosis of autism is a challenging issue in the low and middle income countries due to lack of trained professionals, low cost available tools and infrastructure. In this paper, we proposed a mobile interactive automated application named prottoy to screen autism between 3 to 11 years children using Bengali version of Childhood Autism Spectrum Test. It was translated into Bengali by following cross cultural validation schemes. Pictorial representation of each question was placed into this apps. So, parents can easily check autism of their children by understanding the scenarios of each question. After screening, this app is automatically manipulated user response and detected the possibility of autism of their children. We expect that this app will promote screening that help us to detect autism early of the children in Bangladesh.

Background No study has examined how child and maternal psychopathological difficulties and family factors contribute to the health-related quality of life (HRQOL) of mothers of children with attention deficit hyperactivity (ADHD). Aims To investigate the impact of children’s diagnosis of ADHD, children’s and maternal psychopathology and significant sociodemographic variables of the children, parents and family on HRQOL of mothers of children with ADHD and those of children with typical development (TD) in Taiwan. Methods and procedures Children with ADHD (n = 257) and children with typical development (n = 324) and their mothers were recruited from a psychiatric clinic of a medical center and 10 elementary schools and four high schools in northern Taiwan. Maternal HRQOL was assessed with the World Health Organization Quality of Life – BREF, while the other factors were screened using the Chinese version of the Childhood Autism Spectrum Test for autistic traits, the Swanson, Nolan, and Pelham, version IV scale for ADHD symptoms, the Child Behavior Checklist for behavioral and emotional problems, The Center for Epidemiologic Studies Depression Scale for maternal depression and interpersonal problems, the Adult ADHD Self-report Scale for maternal ADHD symptoms, and the Family APGAR for family support. Outcomes and results Mothers of children with ADHD had significantly worse HRQOL in all four domains compared with those of children with typical development. Multiple regressions found that factors consistently related to the HRQOL of mothers of children with ADHD and those of children with TD were maternal depression and perceived family support after controlling for several familial, parental and child variables. HRQOL of mothers of children with ADHD and those of children with TD was more closely related to her own and family factors rather than mother- or teacher-rated ADHD symptoms, clinical diagnosis of ADHD or psychopathology of the child. Conclusions and implications Screening for maternal HRQOL, depressive symptoms and family support systems and mental health services for mothers of children with ADHD are warranted based on these findings.

The Childhood Autism Spectrum Test (CAST; Scott, Baron-Cohen, Bolton & Brayne, 2002) has proved to be a good test for screening autism spectrum disorders (ASD) and social communication problems. This study provides evidence on its psychometric properties, describe its validity for screening and provides data on its discriminative capabilities in a Spanish sample of 4-12 year-old children from community and clinical settings (N = 1460 and 36, respectively). Factorial and convergent validity is also assessed. The full Spanish version with a cut-off score of 15 presented a high sensitivity (83.9%) and specificity (92.5%), a positive predictive value (PPV) of .63 and an internal consistency (α) of .826. Some items showed low discriminating power and these results led us to propose a reduced version with 28 items and a cut-off score of 13, which presented a high sensitivity (85.7%) and specificity (91.16%), a PPV of .61 and an α of .839. Correlations were high between the Spanish full and reduced versions of the CAST, and ADI-R (Autism Diagnostic Interview Revised) and ADOS-2 (Autism Diagnostic Observation Schedule, Second Edition). Like previous adaptation studies, a two-factor structure was found. The data show that the CAST can be a valid and reliable questionnaire for ASD screening in Spanish clinical and community populations. Autism Res 2017, 10: 1491-1498. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

We studied three patients with Unverricht–Lundborg disease for autistic features along with other clinical features associated with progressive myoclonus epilepsy. We diagnosed this disease based on noise and touch sensitive myoclonus, ataxia, cognitive decline, typical EEG features, normal MRI of the brain and applied Children's Global Assessment Scale and Childhood Autism Spectrum Test to these children. The CGAS score was 35 in two and 50 in one of them. CAST scores were above 15 in all of three of them. Autistic features may be an important clinical feature of this disease. History and physical examination for myoclonus should probably be taken in autistic children., Highlights • Unverricht–Lundborg disease can present with autistic features and hyperactivity. • Main autistic features are an absence of eye contact and avoidance of strangers and absence of attachment to the parents. • Children's Global Assessment Scale scores may be moderately to severely affected. • Childhood Autism Spectrum Test scores may be above the cutoff of 15.

Background: There is a marked male preponderance in autism spectrum conditions. The extreme male brain theory and the fetal androgen theory of autism suggest that elevated prenatal testosterone exposure is a key contributor to autistic traits. The current paper reports findings from two separate studies that test this hypothesis. \ud Methods: A parent-report questionnaire, the Childhood Autism Spectrum Test (CAST), was employed to measure autistic traits in both studies. The first study examined autistic traits in young children with congenital adrenal hyperplasia (CAH), a condition causing unusually high concentrations of testosterone prenatally in girls. 81 children with CAH (43 girls) and 72 unaffected relatives (41 girls), aged 4 to 11 years, were assessed. The second study examined autistic traits in relation to amniotic testosterone in 92 typically-developing children (48 girls), aged 3 to 5 years. \ud Results: Findings from neither study supported the association between prenatal androgen (testosterone) exposure and autistic traits. Specifically, young girls with and without CAH did not differ significantly in CAST scores and amniotic testosterone concentrations were not significantly associated with CAST scores in boys, girls, or the whole sample. \ud Conclusions: These studies do not support a relationship between prenatal testosterone exposure and autistic traits. These findings augment prior research suggesting no consistent relationship between early androgen exposure and autistic traits.

The number of studies addressing the latent structure of specific screening and diagnostic tools for autism spectrum conditions is still limited. The current study explored the latent structure of the Bulgarian CAST (Childhood Autism Spectrum Test) in screening for autism in the Bulgarian population. The data were analysed using factor analyses. A hierarchical model with two primary factors yielded best data fit. This structure is consistent with the two main categories adopted in the DSM-5 and current accounts of the range of conditions broadly falling into two main clusters of symptoms. These results confirm the validity of CAST as a tool for screening for autism spectrum conditions in other cultures and support the construct validity of the model and criteria included in the DSM-5. Furthermore, our results demonstrate how factor analysis can be exploited to reveal the underlying structure of screening tools aimed at capturing the behavioural traits of deficit phenotypes.

Previous studies reported that the prevalence of Autism Spectrum Conditions (ASC) in mainland China is much lower than estimates from developed countries (around 1%). The aim of the study is to apply current screening and standardized diagnostic instruments to a Chinese population to establish a prevalence estimate of ASC in an undiagnosed population in mainland China. We followed the design development used previously in the UK published in 2009 by Baron-Cohen and colleagues. The Mandarin Childhood Autism Spectrum Test (CAST) was validated by screening primary school pupils (n = 737 children age 6-10 years old) in Beijing and by conducting diagnostic assessments using the Autism Diagnostic Observation Schedule and the Autism Diagnostic Interview-Revised. The prevalence estimate was generated after adjusting and imputing for missing values using the inverse probability weighting. Response was high (97%). Using the UK cutoff (≥15), CAST performance has 84% sensitivity and 96% specificity (95% confidence interval [CI]: 46, 98, and 96, 97, respectively). Six out of 103 children, not previously diagnosed, were found to the meet diagnostic criteria (8.5 after adjustment, 95% CI: 1.6, 15.4). The preliminary prevalence in an undiagnosed primary school population in mainland China was 119 per 10,000 (95% CI: 53, 265). The utility of CAST is acceptable as a screening instrument for ASC in large epidemiological studies in China. Using a comparable method, the preliminary prevalence estimate of ASC in mainland China is similar to that of those from developed countries. Autism Res 2015, ●●: ●●-●●. © 2015 The Authors. Autism Research published by Wiley Periodicals, Inc. on behalf of International Society for Autism Research.

Sex differences in social and communication behaviours related to autism spectrum conditions (ASC) have been investigated mainly in Western populations. Little research has been done in Chinese populations. This study explored sex differences related to ASC characteristics by examining differences in item responses and score distributions in relation to a screening instrument, the Childhood Autism Spectrum Test (CAST), used with Chinese children. A Mandarin Chinese version of the CAST (M-CAST) was distributed to 737 children aged 6-11 years in mainstream schools in Beijing. Questionnaires from 682 (93 %) children were available for analysis. The median score for boys was higher than for girls [boys, median = 8 (IQR 6, 11); girls, median = 7 (IQR 4, 9); p

Autism spectrum disorder (ASD) is reported to be increased in neurofibromatosis type 1 (NF1), but it's unknown if ASD screening tools are sensitive and specific for NF1. This study compared the rate at which children with NF1 screen-positive for two ASD screening tools [Modified Checklist for Autism in Toddlers (M-CHAT) and Childhood Autism Spectrum Test (CAST)] to the screen-positive rate of the general population. A retrospective cross-sectional observational design to investigate the association between children with NF1 and at risk status for ASD was used. Medical records of children between 16 months and 11 years of age seen in an NF Clinic were reviewed for an ASD screening questionnaire. There were no statistically significant differences in the screen-positive rate for ASD in NF1 compared to published controls, but mean CAST scores were higher in NF1.

The Childhood Autism Spectrum Test (CAST) (formally known as the Childhood Asperger Screening Test) identifies autism spectrum conditions by measuring social and communication skills. The present study explored the sex distribution of scores. The CAST was distributed to 11,635 children aged 4-9 years in Cambridgeshire primary schools (UK). 3,370 (29%) were returned. The median score was significantly higher in boys (median test, P0.001) (Boys, median = 5 (IQR: 3,8); girls, median = 4 (IQR: 2,6)). There was a predominance of boys (n = 81 (79.4%) over girls (n = 21 (20.6%)) amongst those scoringor= 15. Exclusion of children with ASC did not significantly affect the results. We conclude that different profiles of social and communication skills in boys and girls must be taken into account when measuring these skills in the general population.

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.

The Childhood Asperger Syndrome Test (CAST) is a parental questionnaire to screen for autism spectrum conditions. In this validation study, the CAST was distributed to 1925 children aged 5-11 in mainstream Cambridgeshire schools. A sample of participants received a full diagnostic assessment, conducted blind to screen status. The sensitivity of the CAST, at a designated cut-point of 15, was 100 percent, the specificity was 97 percent and the positive predictive value was 50 percent, using the group’s consensus diagnosis as the gold standard. The accuracy indices varied with the case definition used. The sensitivity of the accuracy statistics to case definition and to missing data was explored. The CAST is useful as a screening test for autism spectrum conditions in epidemiological research. There is not currently enough evidence to recommend the use of the CAST as a screening test within a public health screening programme in the general population.

Limited studies have investigated the latent autistic traits in the mainland Chinese population for autism spectrum conditions (ASC). This study explored the psychometric properties of a Mandarin Chinese version of the CAST in a sample consisting of 737 children in mainstream schools and 50 autistic cases. A combination of categorical data factor analysis and item response theory suggested a good-fit model of a two-factor solution for 28 items on the Mandarin CAST including social and communication, and inflexible/stereotyped language and behaviours (Goodness-of-fit indices: RMSEA = 0.029, CFI = 0.957, TLI = 0.950, SRMR = 0.064). The correlation between the two factors was moderate (GFC = 0.425). This study provided evidence for the CAST as a multidimensional measure for ASC screening in a Chinese population and also showed that the symptom manifestation of ASC in Chinese children shares similarity with western populations.

Autism spectrum conditions (ASC) and attention-deficit/hyperactivity disorder (ADHD) regularly co-occur. Twin studies increasingly indicate that these conditions may have overlapping genetic causes. Less is known about the degree to which specific autistic traits relate to specific behaviours characteristic of ADHD. We hence tested, using the classical twin design, whether specific dimensional autistic traits, including social difficulties, communication atypicalities and repetitive behaviours, would display differential degrees of aetiological overlap with specific traits of ADHD, including hyperactivity/impulsivity and inattention. Parents of approximately 4,000 pairs of 12-year-old twins completed the Childhood Autism Spectrum Test and Conners’ Parent Rating Scale. These measures were divided into subscales corresponding to different types of autistic and ADHD behaviours. Twin model fitting suggested that the degree of genetic overlap was particularly strong between communication difficulties and traits of ADHD (genetic correlations = .47−.51), while repetitive behaviours and social difficulties showed moderate (genetic correlations = .12−.33) and modest (.05−.11) genetic overlap respectively. Environmental overlap was low across all subscales (correlations = .01−.23). These patterns were also apparent at the extremes of the general population, with communication difficulties showing the highest genetic overlap with traits of ADHD. These findings indicate that molecular genetic studies seeking to uncover the shared genetic basis of ASC and ADHD would benefit from taking a symptom-specific approach. Furthermore, they could also help to explain why studies of the communication abilities of individuals with ASC and ADHD have produced overlapping findings. Electronic supplementary material The online version of this article (doi:10.1007/s00787-014-0666-0) contains supplementary material, which is available to authorized users.

A Mandarin Chinese version of the Childhood Autism Spectrum Test (CAST) and Clancy Autism Behaviour Scale (CABS) were applied to 150 children aged 4–11 years old from clinical settings and mainstream schools in Beijing. All the children were further assessed using the Autism Diagnostic Observation Schedule (ADOS) and the Autism Diagnostic Interview-Revised (ADI-R). The validity of two instruments on screening of ASC was examined and compared using receiver operating characteristic (ROC) curve analysis. The validity of CAST (sensitivity: 89%, specificity: 80%, PPV: 70%) was better than the CABS (sensitivity: 58%, specificity: 84%, PPV: 65%). The area under the curve (AUC) of the CAST (AUC = 0.90) was significantly higher than the CABS (AUC = 0.79, p = 0.0002). The Mandarin CAST demonstrated a better validity in distinguishing children with ASC from children without ASC. It is an acceptable candidate as a screening instrument for ASC in large epidemiological study in Chinese population.

Background Acetaminophen is extensively used during pregnancy. But there is a lack of population-representative cohort studies evaluating its effects on a range of neuropsychological and behavioural endpoints. We aimed to assess whether prenatal exposure to acetaminophen is adversely associated with neurodevelopmental outcomes at 1 and 5 years of age. Methods This Spanish birth cohort study included 2644 mother-child pairs recruited during pregnancy. The proportion of liveborn participants evaluated at 1 and 5 years was 88.8% and 79.9%, respectively. Use of acetaminophen was evaluated prospectively in two structured interviews. Ever/never use and frequency of use (never, sporadic, persistent) were measured. Main neurodevelopment outcomes were assessed using Childhood Autism Spectrum Test (CAST), Conner's Kiddie Continuous Performance Test (K-CPT) and ADHD-DSM-IV form list. Regression models were adjusted for social determinants and co-morbidities. Results Over 40% of mothers reported using acetaminophen. Ever-exposed offspring had higher risks of presenting more hyperactivity/impulsivity symptoms [incidence rate ratio (IRR) = 1.41, 95% confidence interval (CI) 1.01-1.98), K-CPT commission errors (IRR = 1.10, 1.03-1.17), and lower detectability scores (coefficient β = -0.75, -0.13--0.02). CAST scores were increased in ever-exposed males (β = 0.63, 0.09-1.18). Increased effect sizes of risks by frequency of use were observed for hyperactivity/impulsivity symptoms (IRR = 2.01, 0.95-4.24) in all children, K-CPT commission errors (IRR = 1.32, 1.05-1.66) and detectability (β = -0.18, -0.36-0.00) in females, and CAST scores in males (β = 1.91, 0.44-3.38). Conclusions Prenatal acetaminophen exposure was associated with a greater number of autism spectrum symptoms in males and showed adverse effects on attention-related outcomes for both genders. These associations seem to be dependent on the frequency of exposure.

I n this issue of the Journal, Dworzynski et al. 1 capitalize on the Twins Early Development Study to shed new light on possible gender differences in autism. In this report, they examine children in the Twins Early Development Study who scored above the screening cutoff of 14 on the Childhood Autism Spectrum Test (CAST) or carried a community diagnosis of an autism spectrum disorder (ASD) endorsed by parent report and whose diagnoses were subsequently confirmed on the Development and Wellbeing Assessment (DAWBA). Children with high CAST scores were considered “diagnosed” if they received a DAWBA and the DAWBA was positive. An important limitation of the study is that 34 of 227 high-CAST boys and 23 of 75 high-CAST girls did not receive DAWBAs yet were assigned to the “undiagnosed” category. Therefore, the most informative subjects were those who had both measurements. Assuming the DAWBA validly differentiates affectation from nonaffectation in this context (this is an assumption), the study yields the following interesting findings: 227 boys and 75 girls screened in TEDS exceeded the CAST cutoff (indicative of a significant gender disparity in the distribution of CAST scores in the population—it is not reported which proportion of each had community diagnoses of ASD by parent report in the Twins Early Development Study); of those who exceeded the CAST cutoff and were assessed with the DAWBA, 56% of the boys but only 38% of the girls met the criteria on the DAWBA (suggestive of a bias in diagnosis); the symptom profile for those who exceeded the cutoff differed by gender (more social deficits in boys, more communicative deficits in girls); and the girls who were diagnosed exhibited more intellectual and behavioral deficits, on average, than their diagnosed male counterparts, suggesting that it requires a relative increase in the total

Objective This study aimed to explore sex differences in autistic traits in relation to diagnosis, to elucidate factors that might differentially impact whether girls versus boys meet diagnostic criteria for autism or a related autism spectrum disorder (ASD). Method Data from a large population-based sample of children were examined. Girls and boys (aged 10–12 years) meeting diagnostic criteria for an ASD were compared with those failing to meet diagnostic criteria despite very high scores on a trait measure of ASD, the Childhood Autism Spectrum Test (CAST). Information about behavioral difficulties as reported by teachers, and early estimates of intellectual functioning, were compared. Results Girls, but not boys, meeting diagnostic criteria for ASD showed significantly more additional problems (low intellectual level, behavioral difficulties) than peers with similarly high CAST scores who did not meet diagnostic criteria. Conclusions These data suggest that, in the absence of additional intellectual or behavioral problems, girls are less likely than boys to meet diagnostic criteria for ASD at equivalently high levels of autistic-like traits. This might reflect gender bias in diagnosis or genuinely better adaptation/compensation in girls.

Background: It has been questioned whether the process of twinning might be a risk factor for autism spectrum conditions (ASC) and autistic traits. Aim: We sought to determine whether autistic traits and probable disorder, as measured by the Childhood Autism Spectrum Test (CAST), were more pronounced in twins compared to singletons. Samples: Data were analyzed from two large population-based samples of UK children, twins (n = 5,142 twin pairs, aged 8 years) and singletons (n = 2,805, aged 5–9 years). Results: Distributions of CAST scores in both groups were negatively skewed and scores for twins were more variable than singletons. Mean CAST total scores and standard errors (SE) were not significantly different for twins (5.1; SE 0.04) compared to singletons (4.9; SE 0.08). Moreover, contrary to expectations, the likelihood of scoring above the threshold for possible ASC was significantly lower in the twins than the singletons (OR = 0.69; P = 0.002). Subsidiary analyses of CAST scores according to sex, twin type, and subscale scores representing the subdomains of autism found a few significant differences (P

Studies of amniotic testosterone in humans suggest that fetal testosterone (fT) is related to specific (but not all) sexually dimorphic aspects of cognition and behaviour. It has also been suggested that autism may be an extreme manifestation of some male-typical traits, both in terms of cognition and neuroanatomy. In this paper, we examine the possibility of a link between autistic traits and fT levels measured in amniotic fluid during routine amniocentesis. Two instruments measuring number of autistic traits (the Childhood Autism Spectrum Test (CAST) and the Child Autism Spectrum Quotient (AQ-Child)) were completed by these women about their children (N = 235), ages 6-10 years. Intelligence Quotient (IQ) was measured in a subset of these children (N = 74). fT levels were positively associated with higher scores on the CAST and AQ-Child. This relationship was seen within sex as well as when the sexes were combined, suggesting this is an effect of fT rather than of sex per se. No relationships were found between overall IQ and the predictor variables, or between IQ and CAST or AQ-Child. These findings are consistent with the hypothesis that prenatal androgen exposure is related to children exhibiting more autistic traits. These results need to be followed up in a much larger sample to test if clinical cases of ASC have elevated fT.

The article describes a pilot and follow-up study of the preliminary development of a new tool to screen for Asperger syndrome (AS) and related social and communication conditions (the Childhood Asperger Syndrome Test, CAST) in children aged 4-11 years, in a non-clinical setting. In the pilot study, parents of 13 children with AS and of 37 typically developing children completed the CAST. There were significant differences between the AS and typical sample means. The pilot was used to establish preliminary cut-off scores for the CAST. In the main study, parents of 1150 primary-school-age children were sent the CAST, and 174 took part in the full data analysis. Results suggest that compared with other tools currently available, the CAST may be useful for identifying children at risk for AS and related conditions, in a mainstream non-clinical sample. Further research is ongoing.

Context Genetic factors play an important role in the etiology of both autism spectrum disorders and autistic traits. However, little is known about the etiologic consistency of autistic traits across levels of severity. Objective To compare the etiology of typical variation in autistic traits with extreme scoring groups (including top 1%) that mimicked the prevalence of diagnosed autism spectrum disorders in the largest twin study of autistic traits to date. Design Twin study using phenotypic analysis and genetic model-fitting in the total sample and extreme scoring groups (top 5%, 2.5%, and 1%). Setting A nationally representative twin sample from the general population of England. Participants The families of 5968 pairs aged 12 years old in the Twins’ Early Development Study. Main Outcome Measure Autistic traits as assessed by the Childhood Autism Spectrum Test. Results Moderate to high heritability was found for autistic traits in the general population (53% for females and 72% for males). High heritability was found in extreme-scoring groups. There were no differences in heritability among extreme groups or between the extreme groups and the general population. A continuous liability shift toward autistic trait affectedness was seen in the cotwins of individuals scoring in the top 1%, suggesting shared etiology between extreme scores and normal variation. Conclusion This evidence of similar etiology across normal variation and the extremes has implications for molecular genetic models of autism spectrum disorders and for conceptualizing autism spectrum disorders as the quantitative extreme of a neurodevelopmental continuum.

Background The etiology of Autism Spectrum Disorder (ASD) has been recently debated due to emerging findings on the importance of shared environmental influences. However, two recent twin studies do not support this and instead re-affirm strong genetic effects on the liability to ASD, a finding consistent with previous reports. This study conducts a systematic review and meta-analysis of all twin studies of ASD published to date and explores the etiology along the continuum of a quantitative measure of ASD. Methods A PubMed Central, Science Direct, Google Scholar, Web of Knowledge structured search conducted online, to identify all twin studies on ASD published to date. Thirteen primary twin studies were identified, seven were included in the meta-analysis by meeting Systematic Recruitment criterion; correction for selection and ascertainment strategies, and applied prevalences were assessed for these studies. In addition, a quantile DF extremes analysis was carried out on Childhood Autism Spectrum Test scores measured in a population sample of 6,413 twin pairs including affected twins. Results The meta-analysis correlations for monozygotic twins (MZ) were almost perfect at .98 (95% Confidence Interval, .96–.99). The dizygotic (DZ) correlation, however, was .53 (95% CI .44–.60) when ASD prevalence rate was set at 5% (in line with the Broad Phenotype of ASD) and increased to .67 (95% CI .61–.72) when applying a prevalence rate of 1%. The meta-analytic heritability estimates were substantial: 64–91%. Shared environmental effects became significant as the prevalence rate decreased from 5–1%: 07–35%. The DF analyses show that for the most part, there is no departure from linearity in heritability. Conclusions We demonstrate that: (a) ASD is due to strong genetic effects; (b) shared environmental effects become significant as a function of lower prevalence rate; (c) previously reported significant shared environmental influences are likely a statistical artefact of overinclusion of concordant DZ twins.