Objective: This study was carried out to examine the efficacy of a 12-week, low-intensity (1-hour/wk of therapist contact), parent-delivered intervention for toddlers at risk for autism spectrum ...disorders (ASD) aged 14 to 24 months and their families. Method: A randomized controlled trial involving 98 children and families was carried out in three different sites investigating the efficacy of a parent delivery of the Early Start Denver Model (P-ESDM), which fosters parental use of a child-centered responsive interaction style that embeds many teaching opportunities into play, compared to community treatment as usual. Assessments were completed at baseline and 12 weeks later, immediately after the end of parent coaching sessions. Results: There was no effect of group assignment on parent-child interaction characteristics or on any child outcomes. Both groups of parents improved interaction skills, and both groups of children demonstrated progress. Parents receiving P-ESDM demonstrated significantly stronger working alliances with their therapists than did the community group. Children in the community group received significantly more intervention hours than those in the P-ESDM group. For the group as a whole, both younger child age at the start of intervention and a greater number of intervention hours were positively related to the degree of improvement in children's behavior for most variables. Conclusions: Parent-implemented intervention studies for early ASD thus far have not demonstrated the large effects seen in intensive-treatment studies. Evidence that both younger age and more intervention hours positively affect developmental rates has implications for clinical practice, service delivery, and public policy. (Contains 5 tables.)
Objective: To examine prospectively the emergence of behavioral signs of autism in the first years of life in infants at low and high risk for autism. Method: A prospective longitudinal design was ...used to compare 25 infants later diagnosed with an autism spectrum disorder (ASD) with 25 gender-matched low-risk children later determined to have typical development. Participants were evaluated at 6, 12, 18, 24, and 36 months of age. Frequencies of gaze to faces, social smiles, and directed vocalizations were coded from video and rated by examiners. Results: The frequency of gaze to faces, shared smiles, and vocalizations to others were highly comparable between groups at 6 months of age, but significantly declining trajectories over time were apparent in the group later diagnosed with ASD. Group differences were significant by 12 months of age on most variables. Although repeated evaluation documented loss of skills in most infants with ASD, most parents did not report a regression in their child's development. Conclusions: These results suggest that behavioral signs of autism are not present at birth, as once suggested by Kanner, but emerge over time through a process of diminishment of key social communication behaviors. More children may present with a regressive course than previously thought, but parent report methods do not capture this phenomenon well. Implications for onset classification systems and clinical screening are also discussed. (Contains 4 figures and 5 tables.)
Objective: First-degree relatives of persons with an autism spectrum disorder (ASD) are at increased risk for ASD-related characteristics. As little is known about the early expression of these ...characteristics, this study characterizes the non-ASD outcomes of 3-year-old high-risk (HR) siblings of children with ASD. Method: Two groups of children without ASD participated: 507 HR siblings and 324 low-risk (LR) control subjects (no known relatives with ASD). Children were enrolled at a mean age of 8 months, and outcomes were assessed at 3 years. Outcome measures were Autism Diagnostic Observation Schedule (ADOS) calibrated severity scores, and Mullen Verbal and Non-Verbal Developmental Quotients (DQ). Results: At 3 years, HR siblings without an ASD outcome exhibited higher mean ADOS severity scores and lower verbal and non-verbal DQs than LR controls. HR siblings were over-represented (21% HR versus 7% LR) in latent classes characterized by elevated ADOS severity and/or low to low-average DQs. The remaining HR siblings without ASD outcomes (79%) belonged to classes in which they were not differentially represented with respect to LR siblings. Conclusions: Having removed a previously identified 18.7% of HR siblings with ASD outcomes from all analyses, HR siblings nevertheless exhibited higher mean levels of ASD severity and lower levels of developmental functioning than LR children. However, the latent class membership of four-fifths of the HR siblings was not significantly different from that of LR control subjects. One-fifth of HR siblings belonged to classes characterized by higher ASD severity and/or lower levels of developmental functioning. This empirically derived characterization of an early-emerging pattern of difficulties in a minority of 3-year-old HR siblings suggests the importance of developmental surveillance and early intervention for these children. (Contains 1 figure and 7 tables.)
We prospectively examined evidence for the sustained effects of early intervention based on a follow-up study of 39 children with ASD who began participation in a randomized clinical trial testing ...the effectiveness of the Early Start Denver Model (ESDM) at age 18 to 30 months. The intervention, conducted at a high level of intensity in-home for 2 years, showed evidence of efficacy immediately posttreatment.
This group of children was assessed at age 6 years, 2 years after the intervention ended, across multiple domains of functioning by clinicians naive to previous intervention group status.
The ESDM group, on average, maintained gains made in early intervention during the 2-year follow-up period in overall intellectual ability, adaptive behavior, symptom severity, and challenging behavior. No group differences in core autism symptoms were found immediately posttreatment; however, 2 years later, the ESDM group demonstrated improved core autism symptoms and adaptive behavior as compared with the community-intervention-as-usual (COM) group. The 2 groups were not significantly different in terms of intellectual functioning at age 6 years. Both groups received equivalent intervention hours during the original study, but the ESDM group received fewer hours during the follow-up period.
These results provide evidence that gains from early intensive intervention are maintained 2 years later. Notably, core autism symptoms improved in the ESDM group over the follow-up period relative to the COM group. This improvement occurred at the same time that the ESDM group received significantly fewer services. This is the first study to examine the role of early ESDM behavioral intervention initiated at less than 30 months of age in altering the longer-term developmental course of autism.
Earlier autism diagnosis, the importance of early intervention, and development of specific interventions for young children have contributed to the emergence of similar, empirically supported, ...autism interventions that represent the merging of applied behavioral and developmental sciences. “Naturalistic Developmental Behavioral Interventions (NDBI)” are implemented in natural settings, involve shared control between child and therapist, utilize natural contingencies, and use a variety of behavioral strategies to teach developmentally appropriate and prerequisite skills. We describe the development of NDBIs, their theoretical bases, empirical support, requisite characteristics, common features, and suggest future research needs. We wish to bring parsimony to a field that includes interventions with different names but common features thus improving understanding and choice-making among families, service providers and referring agencies.
The recurrence risk of autism spectrum disorders (ASD) is estimated to be between 3% and 10%, but previous research was limited by small sample sizes and biases related to ascertainment, reporting, ...and stoppage factors. This study used prospective methods to obtain an updated estimate of sibling recurrence risk for ASD.
A prospective longitudinal study of infants at risk for ASD was conducted by a multisite international network, the Baby Siblings Research Consortium. Infants (n = 664) with an older biological sibling with ASD were followed from early in life to 36 months, when they were classified as having or not having ASD. An ASD classification required surpassing the cutoff of the Autism Diagnostic Observation Schedule and receiving a clinical diagnosis from an expert clinician.
A total of 18.7% of the infants developed ASD. Infant gender and the presence of >1 older affected sibling were significant predictors of ASD outcome, and there was an almost threefold increase in risk for male subjects and an additional twofold increase in risk if there was >1 older affected sibling. The age of the infant at study enrollment, the gender and functioning level of the infant's older sibling, and other demographic factors did not predict ASD outcome.
The sibling recurrence rate of ASD is higher than suggested by previous estimates. The size of the current sample and prospective nature of data collection minimized many limitations of previous studies of sibling recurrence. Clinical implications, including genetic counseling, are discussed.
Background: Unusual responses to sensory stimuli are seen in many children with autism. Their presence was highlighted both in early accounts of autism and in more recent first‐person descriptions. ...There is a widespread belief that sensory symptoms characterize autism and differentiate it from other disorders. This paper examines the empirical evidence for this assumption.
Method: All controlled experimental laboratory investigations published since 1960 were identified through systematic searches using Medline/PubMed and PsycInfo search engines. A total of 48 empirical papers and 27 theoretical or conceptual papers were reviewed.
Results: Sensory symptoms are more frequent and prominent in children with autism than in typically developing children, but there is not good evidence that these symptoms differentiate autism from other developmental disorders. Certain groups, including children with fragile X syndrome and those who are deaf‐blind, appear to demonstrate higher rates of sensory symptoms than children with autism. In reviewing the evidence relevant to two theories of sensory dysfunction in autism, over‐ and under‐arousal theory, we find that there is very little support for hyper‐arousal and failure of habituation in autism. There is more evidence that children with autism, as a group, are hypo‐responsive to sensory stimuli, but there are also multiple failures to replicate findings and studies that demonstrate lack of group differences.
Conclusions: The use of different methods, the study of different sensory modalities, and the changing scientific standards across decades complicate interpretation of this body of work. We close with suggestions for future research in this area.
This study had 3 goals, which were to examine the following: the frequency of atypical development, consistent with the broader autism phenotype, in high-risk infant siblings of children with autism ...spectrum disorder (ASD); the age at which atypical development is first evident; and which developmental domains are affected.
A prospective longitudinal design was used to compare 294 high-risk infants and 116 low-risk infants. Participants were tested at 6, 12, 18, 24, and 36 months of age. At the final visit, outcome was classified as ASD, Typical Development (TD), or Non-TD (defined as elevated Autism Diagnostic Observation Schedule ADOS score, low Mullen Scale scores, or both).
Of the high-risk group, 28% were classified as Non-TD at 36 months of age. Growth curve models demonstrated that the Non-TD group could not be distinguished from the other groups at 6 months of age, but differed significantly from the Low-Risk TD group by 12 months on multiple measures. The Non-TD group demonstrated atypical development in cognitive, motor, language, and social domains, with differences particularly prominent in the social-communication domain.
These results demonstrate that features of atypical development, consistent with the broader autism phenotype, are detectable by the first birthday and affect development in multiple domains. This highlights the necessity for close developmental surveillance of infant siblings of children with ASD, along with implementation of appropriate interventions as needed.
International research to understand infant patterns of development in autism spectrum disorders (ASDs) has recently focused on a research paradigm involving prospective longitudinal studies of ...infant siblings of children with autism. Such designs use a comparison group of infant siblings without any familial risks (the low-risk group) to gather longitudinal information about developmental skills across the first 3 years of life, followed by clinical diagnosis of ASD at 36 months. This review focuses on five topics: presence of ASD in the infant sibling groups, patterns and characteristics of motor development, patterns and characteristics of social and emotional development, patterns and characteristics of intentional communication, both verbal and nonverbal, and patterns that mark the onset of behaviors pathognomonic for ASD. Symptoms in all these areas typically begin to be detected during the age period of 12-24 months in infants who will develop autism. Onset of the symptoms occurs at varying ages and in varying patterns, but the pattern of frank loss of skills and marked regression reported from previous retrospective studies in 20-30% of children is seldom reported in these infant sibling prospective studies. Two surprises involve the very early onset of repetitive and unusual sensory behaviors, and the lack of predictive symptoms at the age of 6 months. Contrary to current views that autism is a disorder that profoundly affects social development from the earliest months of life, the data from these studies presents a picture of autism as a disorder involving symptoms across multiple domains with a gradual onset that changes both ongoing developmental rate and established behavioral patterns across the first 2-3 years of life.
This single-blind, randomized, multisite, intent-to-treat study was designed to replicate and extend Dawson et al.'s (Pediatrics. 2010;125: e17-e23) randomized controlled trial testing the effects of ...the Early Start Denver Model (ESDM), an intensive play- and routines-based intervention delivered in natural settings.
A randomized controlled trial was conducted at 3 universities. One hundred eighteen children 14 to 24 months old with autism spectrum disorder were enrolled and randomly assigned to ESDM or community interventions for 27 months. Eighty-one children completed the full treatment course and all assessments; data from all 118 children were used in analyses. Children assigned to the ESDM intervention received 3 months of weekly parent coaching followed by 24 months of 15 hour per week (on average) 1:1 treatment weekly on average in homes or daycare settings from supervised therapy assistants while parents received coaching 4 hours monthly from a certified ESDM therapist.
For the primary analyses, there were time-by-group and time-by-group-by-site interactions for language outcome. In the significant 3-way interaction involving site, 2 sites showed a significant ESDM advantage and the third site showed no significant group differences. In the planned 2-way analysis that pooled data across all 3 sites, there was a significant advantage found for the ESDM group. For the secondary analyses, there were no significant differences between the ESDM and community groups involving developmental quotient, autism severity, or adaptive behavior. The treatment effect of group on language outcomes was not moderated by baseline developmental quotient, autism severity, or language.
Results of the primary analysis provide a partial replication of Dawson et al.'s 2010 language findings.
Intensive Intervention for Toddlers with Autism; https://clinicaltrials.gov/; NCT00698997.
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