Results of small trials suggest that early interventions for social communication are effective for the treatment of autism in children. We therefore investigated the efficacy of such an intervention in a larger trial. Children with core autism (aged 2 years to 4 years and 11 months) were randomly assigned in a one-to-one ratio to a parent-mediated communication-focused (Preschool Autism Communication Trial [PACT]) intervention or treatment as usual at three specialist centres in the UK. Those assigned to PACT were also given treatment as usual. Randomisation was by use of minimisation of probability in the marginal distribution of treatment centre, age (42 months), and autism severity (Autism Diagnostic Observation Schedule-Generic [ADOS-G] algorithm score 12-17 or 18-24). Primary outcome was severity of autism symptoms (a total score of social communication algorithm items from ADOS-G, higher score indicating greater severity) at 13 months. Complementary secondary outcomes were measures of parent-child interaction, child language, and adaptive functioning in school. Analysis was by intention to treat. This study is registered as an International Standard Randomised Controlled Trial, number ISRCTN58133827. 152 children were recruited. 77 were assigned to PACT (London [n=26], Manchester [n=26], and Newcastle [n=25]); and 75 to treatment as usual (London [n=26], Manchester [n=26], and Newcastle [n=23]). At the 13-month endpoint, the severity of symptoms was reduced by 3.9 points (SD 4.7) on the ADOS-G algorithm in the group assigned to PACT, and 2.9 (3.9) in the group assigned to treatment as usual, representing a between-group effect size of -0.24 (95% CI -0.59 to 0.11), after adjustment for centre, sex, socioeconomic status, age, and verbal and non-verbal abilities. Treatment effect was positive for parental synchronous response to child (1.22, 0.85 to 1.59), child initiations with parent (0.41, 0.08 to 0.74), and for parent-child shared attention (0.33, -0.02 to 0.68). Effects on directly assessed language and adaptive functioning in school were small. On the basis of our findings, we cannot recommend the addition of the PACT intervention to treatment as usual for the reduction of autism symptoms; however, a clear benefit was noted for parent-child dyadic social communication. UK Medical Research Council, and UK Department for Children, Schools and Families.

It is not known whether early intervention can improve long-term autism symptom outcomes. We aimed to follow-up the Preschool Autism Communication Trial (PACT), to investigate whether the PACT intervention had a long-term effect on autism symptoms and continued effects on parent and child social interaction. PACT was a randomised controlled trial of a parent-mediated social communication intervention for children aged 2-4 years with core autism. Follow-up ascertainment was done at three specialised clinical services centres in the UK (London, Manchester, and Newcastle) at a median of 5·75 years (IQR 5·42-5·92) from the original trial endpoint. The main blinded outcomes were the comparative severity score (CSS) from the Autism Diagnostic Observation Schedule (ADOS), the Dyadic Communication Assessment Measure (DCMA) of the proportion of child initiatiations when interacting with the parent, and an expressive-receptive language composite. All analyses followed the intention-to-treat principle. PACT is registered with the ISRCTN registry, number ISRCTN58133827. 121 (80%) of the 152 trial participants (59 [77%] of 77 assigned to PACT intervention vs 62 [83%] of 75 assigned to treatment as usual) were traced and consented to be assessed between July, 2013, and September, 2014. Mean age at follow-up was 10·5 years (SD 0·8). Group difference in favour of the PACT intervention based on ADOS CSS of log-odds effect size (ES) was 0·64 (95% CI 0·07 to 1·20) at treatment endpoint and ES 0·70 (95% CI -0·05 to 1·47) at follow-up, giving an overall reduction in symptom severity over the course of the whole trial and follow-up period (ES 0·55, 95% CI 0·14 to 0·91, p=0·004). Group difference in DCMA child initiations at follow-up showed a Cohen's d ES of 0·29 (95% CI -0.02 to 0.57) and was significant over the course of the study (ES 0·33, 95% CI 0·11 to 0·57, p=0·004). There were no group differences in the language composite at follow-up (ES 0·15, 95% CI -0·23 to 0·53). The results are the first to show long-term symptom reduction after a randomised controlled trial of early intervention in autism spectrum disorder. They support the clinical value of the PACT intervention and have implications for developmental theory. Medical Research Council.

The growth of autistic self-advocacy and the neurodiversity movement has brought about new ethical, theoretical and ideological debates within autism theory, research and practice. These debates have had genuine impact within some areas of autism research but their influence is less evident within early intervention research. In this paper, we argue that all autism intervention stakeholders need to understand and actively engage with the views of autistic people and with neurodiversity as a concept and movement. In so doing, intervention researchers and practitioners are required to move away from a normative agenda and pay diligence to environmental goodness-of-fit, autistic developmental trajectories, internal drivers and experiences, and autistic prioritized intervention targets. Autism intervention researchers must respond to these debates by reframing effectiveness, developing tools to measure autistic prioritized outcomes, and forming partnerships with autistic people. There is a pressing need for increased reflection and articulation around how intervention practices align with a neurodiversity framework and greater emphasis within intervention programmes on natural developmental processes, coping strategies, autonomy, and well-being.

Background: In early typical language development, children understand words before they are able to use them in speech. Children with autism spectrum disorders (ASD) generally show impairments in both the comprehension and the production of language. However, the relative degree of delay or impairment in each of these sub‐domains may also be atypical and remains less well‐understood.Aims: Relative delay in receptive and expressive language skills was examined within a large sample of preschoolers with autism. Children's language abilities varied from pre‐verbal to fluent speech.Method & Procedures: Scores on one direct clinician assessment and two parent‐report measures of language were obtained for 152 preschoolers with core autism.Outcomes & Results: As expected, on average, the language ability of the children with autism was lower than typical age norms, albeit with substantial individual variability. On all three language measures, receptive ability was relatively more impaired than expressive ability. Higher non‐verbal ability was associated with such an atypical language profile.Conclusions & Implications: Recognition of the marked receptive language impairment relative to expressive language, found to affect at least one‐third of preschoolers with autism in this sample, has important implications for interacting with these children and for informing appropriate targets in language and communication intervention.

OBJECTIVE: To determine the prevalence of autism spectrum disorder (ASD) in Neurofibromatosis Type 1 (NF1). METHODS: Second-phase population-based epidemiologic study using an allcase NF1 registry in a defined UK 4.1 million population area. A total of 109 (52.7%) of 207 responders from the initial screening phase were grouped by using the parent-rated Social Responsiveness Scale (SRS) as significant ASD (SRS≥76; n = 32), moderate ASD (SRS ≥ 60<76; n = 29), or non-ASD (SRS <60, n = 48). Twenty-three cases from the significant ASD group, 16 from moderate ASD, and 8 from non-ASD (total n = 47), invited proportionately by random selection, were seen for detailed confirmatory ascertainment. Assessments on Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Scale-Generic, and verbal IQ were combined by using standard Collaborative Program for Excellence in Autism criteria into an ASD categorization for each case (ASD, broad ASD with partial features, non-ASD). A preplanned weighted analysis was used to derive prevalence estimates for the whole population. RESULTS: Fourteen (29.5%) of 47 showed ASD, 13 (27.7%) broad ASD, and 20 (42.5%) non-ASD. The ASD/broad ASD group showed male predominance (1.7:1.0), but did not differ significantly from the non-ASD group on IQ, age, socioeconomic status, inheritance, physical severity, or education. The population prevalence estimate is 24.9% ASD (95% confidence interval 13.1%–42.1%) and 20.8% broad ASD (95% confidence interval 10.0%–38.1%); a total of 45.7% showing some ASD spectrum phenotype. CONCLUSIONS: Findings indicate high prevalence of ASD in NF1, with implications for clinical practice and further research into NF1 as a single-gene model for autism.