Continuity of trajectories of autism symptom severity from infancy to childhood.

BACKGROUND: Behavioral symptom trajectories are informative of the development of young children at increased likelihood for autism spectrum disorder (ASD). METHODS: Developmental trajectories of early signs were examined in a cohort of siblings of children diagnosed with ASD (n = 502) from 6 to 18 months using the Autism Observation Scale for Infants (AOSI), and from 18 months to 5-7 years using the Autism Diagnostic Observation Schedule (ADOS). Diagnostic outcomes for ASD at age 3 confirmed diagnosis for 137 children. We further analyzed the conditional probability of a switch from a trajectory measured with the AOSI to a trajectory measured with the ADOS as well as predictors from age 6 months. RESULTS: We derived three early trajectories of behavioral signs ("Low," "Intermediate," and "Increasing") from 6 to 18 months using the AOSI. We then derived three similar, distinct trajectories for the evolution of symptom severity between 18 and 60-84 months of age (Low, Intermediate, Increasing) using the ADOS. Globally, the Low trajectory included children showing fewer ASD signs or symptoms and the Increasing trajectory included children showing more severe symptoms. We also found that most children in the Low AOSI trajectory stayed in the corresponding ADOS trajectory, whereas children in an Increasing AOSI trajectory tended to transition to an Intermediate or Increasing ADOS trajectory. Developmental measures taken at 6 months (early signs of ASD, Fine Motor, and Visual Reception skills) were predictive of trajectory membership. CONCLUSIONS: Results confirm substantial heterogeneity in the early emergence of ASD signs in children at increased likelihood for ASD. Moreover, we showed that the way those early behavioral signs emerge in infants is predictive of later symptomatology. Results yield clear clinical implications, supporting the need to repeatedly assess infants at increased likelihood for ASD as this can be highly indicative of their later development and behavior.

Precursors of self-regulation in infants at elevated likelihood for autism spectrum disorder.

Research concerning temperament in children and adults with autism spectrum disorder (ASD) has suggested a consistent profile of low positive affect, high negative affect, and low regulation (Visser et al., 2016). One area receiving less attention is individual differences among children diagnosed with ASD. The primary objective of this study was to use a person-centered approach to explore heterogeneity of early temperament precursors of regulation in a large sample of infants with elevated familial likelihood of ASD. Early precursors of regulation included temperament assessed at 6, 12, and 24 months whereas outcome measures were diagnosis of ASD, cognitive ability and adaptive behavior at 36 months. Participants included 176 low-likelihood and 473 elevated-likelihood infants, 129 of whom were diagnosed with ASD at 3 years. Results supported a three-profile solution: a well-regulated profile (high positive affect and high attentional focus and shifting), a low attention focus profile (higher attentional shifting compared to attentional focus), and a low attention shifting profile (higher attentional focus compared to attentional shifting). A higher proportion of children diagnosed with ASD were classified into the low attention shifting profile. Furthermore, children with the well-regulated profile were differentiated from the other profiles by a pattern of higher social competence and lower dysregulation whereas children with the low attention focus profile were distinguished from the other profiles by higher cognitive ability at 3 years. The findings indicate that the combination of early positive affect with attention measures may provide an enhanced tool for prediction of self-regulation and later outcomes.

Symptom trajectories in the first 18 months and autism risk in a prospective high-risk cohort.

BACKGROUND: Although early autism spectrum disorder (ASD) detection strategies tend to focus on differences at a point in time, behavioral symptom trajectories may also be informative. METHODS: Developmental trajectories of early signs of ASD were examined in younger siblings of children diagnosed with ASD (n = 499) and infants with no family history of ASD (n = 177). Participants were assessed using the Autism Observation Scale for Infants (AOSI) from 6 to 18 months. Diagnostic outcomes were determined at age 3 years blind to previous assessments. RESULTS: Semiparametric group-based modeling using AOSI scores identified three distinct trajectories: Group 1 ('Low', n = 435, 64.3%) was characterized by a low level and stable evolution of ASD signs, group 2 ('Intermediate', n = 180, 26.6%) had intermediate and stable levels, and group 3 ('Inclining', n = 61, 9.3%) had higher and progressively elevated levels of ASD signs. Among younger siblings, ASD rates at age 3 varied by trajectory of early signs and were highest in the Inclining group, membership in which was highly specific (94.5%) but poorly sensitive (28.5%) to ASD. Children with ASD assigned to the inclining trajectory had more severe symptoms at age 3, but developmental and adaptive functioning did not differ by trajectory membership. CONCLUSIONS: These prospective data emphasize variable early-onset patterns and the importance of a multipronged approach to early surveillance and screening for ASD.

Assessment of Autism Symptoms From 6 to 18 Months of Age Using the Autism Observation Scale for Infants in a Prospective High-Risk Cohort.

The objectives were to characterize behavioral signs of autism spectrum disorder (ASD) in younger siblings of diagnosed children (high-risk; HR) and examine classification features of the Autism Observation Scale for Infants (AOSI). Participants (501 HR and 180 low-risk [LR]) were assessed between 6 and 18 months using the AOSI and at age 3 for ASD diagnoses. Total AOSI scores differentiated HR infants later diagnosed with ASD starting at 12 months. ROC analyses identified 12- and 18-month cutoff scores associated with 0.52 sensitivity and 0.74 specificity and 0.73 sensitivity and 0.65 specificity, respectively. Although classification accuracy does not support use as a standalone screen, the AOSI identifies features associated with ASD starting at 6 months and differentiates HR infants with ASD by 12 months.

Developmental functioning and symptom severity influence age of diagnosis in Canadian preschool children with autism.

BACKGROUND: Early diagnosis of autism spectrum disorder (ASD) is essential in most Canadian jurisdictions to access interventions that improve long-term child outcomes. Our main objective was to identify factors associated with timing of ASD diagnosis in five provinces across Canada. METHODS: Factors influencing age of diagnosis were assessed in the analyses of an inception cohort of children diagnosed with ASD between ages 2 and 5 years. We examined bivariate associations and using a series of multiple variable regression models, evaluated the unique contributions of developmental functioning, ASD symptoms and demographic variables. Children with known genetic abnormalities, or severe sensory or motor impairments interfering with assessment were excluded. RESULTS: Participants were 421 children (84.6% boys). The mean age of diagnosis was 38.2 months (SD=8.7), an average of 19 months after parents identified initial concerns. Factors associated with later diagnosis included more advanced language and cognitive skills, and higher levels of restricted repetitive behaviour symptoms. Child sex and family demographics were not associated with age of diagnosis. In regression analyses, language and cognitive skills accounted for 6.8% of variance in age of diagnosis and ASD symptoms contributed an additional 5.5%. Provincial site accounted for 4.0% of variance in age of diagnosis, independent of developmental skills and ASD symptoms. INTERPRETATION: Diagnosis of ASD occurred, on average, 19 months after parents' initial concerns. Language and cognitive skills, symptom severity and provincial site accounted for variation in age of ASD diagnosis in this Canadian cohort. Variable presentation across the developmental continuum must be considered in planning assessment services to ensure timely ASD diagnosis so that outcomes can be improved. Policy and practice leadership is also needed to reduce interprovincial variability.

Functional impact of global rare copy number variation in autism spectrum disorders.

The autism spectrum disorders (ASDs) are a group of conditions characterized by impairments in reciprocal social interaction and communication, and the presence of restricted and repetitive behaviours. Individuals with an ASD vary greatly in cognitive development, which can range from above average to intellectual disability. Although ASDs are known to be highly heritable ( approximately 90%), the underlying genetic determinants are still largely unknown. Here we analysed the genome-wide characteristics of rare (<1% frequency) copy number variation in ASD using dense genotyping arrays. When comparing 996 ASD individuals of European ancestry to 1,287 matched controls, cases were found to carry a higher global burden of rare, genic copy number variants (CNVs) (1.19 fold, P = 0.012), especially so for loci previously implicated in either ASD and/or intellectual disability (1.69 fold, P = 3.4 x 10(-4)). Among the CNVs there were numerous de novo and inherited events, sometimes in combination in a given family, implicating many novel ASD genes such as SHANK2, SYNGAP1, DLGAP2 and the X-linked DDX53-PTCHD1 locus. We also discovered an enrichment of CNVs disrupting functional gene sets involved in cellular proliferation, projection and motility, and GTPase/Ras signalling. Our results reveal many new genetic and functional targets in ASD that may lead to final connected pathways.

Mapping autism risk loci using genetic linkage and chromosomal rearrangements.

Autism spectrum disorders (ASDs) are common, heritable neurodevelopmental conditions. The genetic architecture of ASDs is complex, requiring large samples to overcome heterogeneity. Here we broaden coverage and sample size relative to other studies of ASDs by using Affymetrix 10K SNP arrays and 1,181 [corrected] families with at least two affected individuals, performing the largest linkage scan to date while also analyzing copy number variation in these families. Linkage and copy number variation analyses implicate chromosome 11p12-p13 and neurexins, respectively, among other candidate loci. Neurexins team with previously implicated neuroligins for glutamatergic synaptogenesis, highlighting glutamate-related genes as promising candidates for contributing to ASDs.

Autism spectrum disorder in infancy: developmental considerations in treatment targets.

PURPOSE OF REVIEW: This review explores recent literature to prioritize aspects of development to be targeted by intervention for infants and toddlers with autism spectrum disorder (ASD). RECENT FINDINGS: Recent investigation of early development in ASD, including prospective studies of infants at increased risk (i.e., those with an affected older sibling) identifies impairments in four key developmental domains that are predictive of ASD. These domains are early attentional control, emotion regulation, social orienting/approach, and communication development. Reciprocal relationships exist among these domains, both in ASD and in typical development. Thus, these domains represent key intervention targets, informing treatment models under investigation in recent clinical trials. SUMMARY: By targeting the earliest and foundational manifestations of atypical development, we can capitalize on neural plasticity and build skills that are most likely to have scaffolding effects on development. The optimal timing and procedures of intervention remain empirical questions, but as the field moves toward earlier identification of risk, we are now poised to evaluate the impact of tailored approaches before the developmental cascade that leads to ASD is fully manifested. Consideration regarding community translation of ASD-specific interventions for infants and toddlers is also needed, with a focus on feasibility, cost-effectiveness, and sustainability.

Behavioural reactions to an emotion evoking task in infants at increased likelihood for autism spectrum disorder.

Infants at increased likelihood for autism spectrum disorder (ASD) exhibit more negative affect and avoidance behaviour than typically developing infants, and children with ASD express fear differently than typically developing peers. We examined behavioural reactions to emotion-evoking stimuli in infants at increased familial likelihood for ASD. Participants included 55 increased likelihood (IL) infants (i.e., siblings of children diagnosed with ASD) and 27 typical likelihood (TL) infants (i.e., no family history of ASD). At 18 months, we showed infants two masks that commonly elicit fearful responses in older children and examined potential behavioural differences in approach, avoidance, 'freezing', crying, gaze aversion, and smiling. At 24 months, infants were assessed with the Toddler Module of the Autism Diagnostic Observation Schedule, 2nd edition (ADOS-2). Results of video-based coding showed that (1) IL infants exhibited more intense avoidance behaviour than TL infants in response to masks, and (2) intensity of avoidance and duration of freezing were positively correlated with ADOS-2 symptom severity scores. Findings suggest that differences in response to emotion-eliciting stimuli may predict later ASD symptoms. Such behavioural differences may inform early detection and intervention in ASD.

Community implementation of a brief parent mediated intervention for toddlers with probable or confirmed autism spectrum disorder: feasibility, acceptability, and drivers of success (IE Drmic et al.).

Background: Social ABCs is a caregiver-mediated Naturalistic Developmental Behavioral Intervention for toddlers with confirmed/suspected Autism Spectrum Disorder (ASD), with evidence in controlled research settings. Information is lacking on implementation in community settings. We reported on the treatment effectiveness of this program within a community setting, and the current paper describes the implementation phase of this work. Distinguishing between treatment and implementation effectiveness is critical for transporting interventions from laboratory to community. Objectives: Describe the implementation of Social ABCs through a large public autism service, supported by a research-community partnership. Methods: We describe this project through the Exploration, Preparation, Implementation, Sustainment (EPIS) framework as it focuses on implementation of evidence-based practices in publicly funded services. We apply this framework to the reporting stage. This project took place in the context of a 3-year government-funded pilot at a hospital-based publicly funded autism service. Participants: Program developers; Autism Service team; toddlers with suspected/confirmed ASD aged 14-34 months (M = 25.18 months) and their caregivers. Training/supervision: Provided by program developers at tapering intensity. Evaluation: Caregivers completed the Caregiver Diary and satisfaction surveys. We explored training processes, intervention uptake, acceptability, adaptations to fit community context, appropriateness, perceived impact, and facilitators/barriers. Results: Six coaches were trained to fidelity, and three of these were further trained as Site Trainers. 183 clinically referred families enrolled and 89.4% completed the 12-week program. Caregivers reported increases in adherence and competence, high satisfaction and perceived benefits for their children. Coaches reported high satisfaction. Toddlers were appropriately identified to receive the intervention. Referral processes improved, including decreased referral age, and increased family readiness for diagnostic assessment and subsequent services. Conclusions: Social ABCs was successfully implemented in a community service through a research-community partnership. The program was feasible, acceptable, and appropriate within a community context. Drivers of success included funding, institutional support, shared decision-making, adaptations to fit context, leadership support, perceived positive impact, and commitment to evaluation.

Temperament in Infancy Predicts Internalizing and Externalizing Problem Behavior at Age 5 in Children With an Increased Likelihood of Autism Spectrum Disorder.

Differences in temperament have been linked to later mental health. Children with autism spectrum disorder (ASD) have an increased likelihood of experiencing such problems, including anxiety, depression, attention deficit/hyperactivity disorder, and oppositional defiant disorder; yet, relations between early temperament and later mental health are not well understood. In this paper, we assess the relationship between temperament in infancy and internalizing and externalizing behavior at age 5, in 178 children at an increased likelihood of being diagnosed with ASD (i.e., younger siblings of children with ASD). Temperament was assessed using the parent-reported Infant Behavior Questionnaire (IBQ) at 6 and 12 months of age and the Toddler Behavior Assessment Questionnaire-Revised (TBAQ-R) at 24 months of age. Mental health problems were assessed using the parent-reported Child Behavior Checklist (CBCL) at age 5. The data were analyzed using hierarchical multiple regressions, with individual temperament subscale scores as single predictor variables (Subscale Score) or temperament profiles using confirmatory factor analyses (Person-Centered Profile) in the first block, Autism Diagnostic Observation Schedule total severity scores at age 3 in the second block, and expressive and receptive language scores (from Mullen Scales of Early Learning) at age 3 in the third block for each model. Three main findings were: (1) 4 of 6 IBQ subscales at both 6 and 12 months significantly predicted internalizing and externalizing problems at age 5; (2) 9 and 8 of 13 TBAQ-R subscales at 24 months significantly predicted internalizing and externalizing problems, respectively, at age 5; and (3) a "sticky attention" temperament profile significantly predicted internalizing problems, whereas a "low-focused" profile significantly predicted externalizing problems, both at age 5. The results of this study support the supposition that temperament is a trans-diagnostic risk factor for later mental health conditions. Exploring temperament profiles and trajectories may illuminate early avenues for prevention in siblings of children with ASD who are at an increased likelihood of experiencing mental health problems, regardless of ASD diagnostic status.

Effectiveness of a parent-mediated intervention for toddlers with autism spectrum disorder: Evidence from a large community implementation.

LAY ABSTRACT: In an effort to increase access to intervention as early as possible for toddlers with autism spectrum disorder or signs thereof, many researchers have developed interventions that can be delivered by parents in their own homes. These parent-mediated approaches have gained a lot of research attention in recent years and have been found to be helpful in terms of parent and toddler learning. Several studies have used a rigorous research design (a randomized controlled trial) to show that parent-mediated intervention can work under ideal well-controlled conditions. To build on this evidence, we also need to examine whether parent-mediated interventions can be taught well through community service providers and delivered in more "real-world" conditions. This study used a research-community partnership to provide a parent-mediated intervention (called the Social ABCs) to 179 families (mean toddler age was 25 months; ranging from 14 to 34 months). Almost 90% of the families completed the 12-week program and 70% returned for a follow-up assessment 3 months later. Analyses showed that parents learned the strategies that were designed to help them support their toddlers' development. Also, toddlers made gains in their language, communication, and social skills. Importantly, parents' use of the strategies was related to toddlers' skill gains, suggesting that the use of the strategies made a difference for the toddlers. Findings support the use of parent-mediated intervention in this very young age group and suggest that such intervention approaches should be made available for community delivery.

Early trajectories of motor skills in infant siblings of children with autism spectrum disorder.

Delays in motor development are not considered a core feature of autism spectrum disorder (ASD). Yet, recent studies of infant siblings of children with ASD suggest that early delays in motor skills may be associated with later delays in developmental areas considered to be core features of an ASD diagnosis. While these studies demonstrate the longitudinal association between core features and motor delays observed at single time points, there is considerable interest in studying the trajectories of motor development over the first 3 years of life. To accomplish this, we investigated early trajectories of motor development in a cohort of 499 infant siblings of children with ASD and 176 children with no family history of ASD. Data for the current study were drawn from the prospective, multi-site, Canadian Infant Sibling Study. We evaluated trajectories of fine and gross motor development over the first 3 years using group-based trajectory modeling. Our results show that membership for both fine and gross motor trajectory groups was related to expressive language skills, receptive language skills, ASD symptom severity scores, and diagnostic classification at age 3. These results provide evidence that the trajectory of a child's early motor development may have important prognostic implications in ASD.

Brief parent training in pivotal response treatment for preschoolers with autism.

BACKGROUND: Evidence of improved outcomes with early behavioural intervention has placed the early treatment of autism as a health priority. However, long waiting lists for treatment often preclude timely access, raising the question of whether parents could be trained in the interim. Parent training in pivotal response treatment (PRT) has been shown to enhance the communication skills of children with autism. This is typically provided within a 25-hour programme, although less intensive parent training may also be effective. The main objective of the present study was to evaluate the efficacy of brief training in PRT for parents of preschoolers with autism, who were awaiting, or unable to access, more comprehensive treatment. METHOD: Eight preschoolers with autism and their parents participated in the study. A non-concurrent multiple (across-participants) baseline design was used, in which parents were seen individually for three 2-hour training sessions on PRT. Child and parent outcomes were assessed before, immediately after, and 2 to 4 months following training using standardised tests, questionnaires and behaviour coded directly from video recordings. RESULTS: Overall, children's communication skills, namely functional utterances, increased following training. Parents' fidelity in implementing PRT techniques also improved after training, and generally these changes were maintained at follow-up. A moderate to strong relationship was found between parents' increased ability to implement PRT techniques and improvement in the children's communication skills. CONCLUSION: Our findings suggest that brief parent training in PRT promises to provide an immediate, cost-effective intervention that could be adopted widely.

Comparing the 1-year impact of preschool autism intervention programs in two Canadian provinces.

Autism spectrum disorder (ASD) is associated with early differences in children's social interactions, communication, and play/interests. In many countries, considerable resources are invested in early intensive behavioral intervention (EIBI) programs for children with ASD, which aim to build adaptive skills and prevent or treat problem behavior. However, these programs vary widely in structure and delivery. Research evidence supports the efficacy of EIBI, but large knowledge gaps remain about the effectiveness of publicly funded EIBI programs. With policy-makers as formal research partners, we compared children's progress over 1 year in public preschool programs in adjacent Canadian provinces, New Brunswick (NB) and Nova Scotia (NS). In NB, children received up to 20 hr/week of comprehensive EIBI in a publicly funded, privately provided program. In NS, children received up to 15 hr/week of Pivotal Response Treatment and Positive Behavior Support delivered through the publicly funded healthcare system. In this observational parallel cohort study, we collected parent-reported data on 298 NB preschoolers (76.5% boys) and 221 NS preschoolers (86.9% boys) at EIBI start and 1 year later. Multilevel analysis revealed significant differences at baseline: NS children were older, with lower adaptive functioning and more severe ASD symptoms than NB children. Despite these pre-treatment differences that favor NB, children in both provinces showed similar adaptive functioning gains and reductions of maladaptive behavior. No changes were seen in mean ASD symptom severity in either province over time. Results highlight the value of evaluating interventions in their implementation contexts, and have important implications for devising optimal ASD policy. Autism Research 2019, 12: 667-681. © 2019 International Society for Autism Research,Wiley Periodicals, Inc. LAY SUMMARY: We need to know more about the impact of different forms of early intensive behavioral intervention (EIBI) for young children with autism spectrum disorder (ASD). We showed that preschoolers with ASD gained important skills while in public EIBI programs in two Canadian provinces. We also saw that differences in how EIBI programs are structured and characteristics of children who are served may affect outcomes. For these reasons, policy making requires evidence that fits the local context.

Executive function in preschoolers: a review using an integrative framework.

During the last 2 decades, major advances have been made in understanding the development of executive functions (EFs) in early childhood. This article reviews the EF literature during the preschool period using an integrative framework. The framework adopted considers EF to be a unitary construct with partially dissociable components (A. Miyake et al., 2000). The authors focus on 3 EF components: working memory, response inhibition, and shifting. For the present purposes, the central executive is conceived of as a central attention system that is involved in all EF component operations. Research to date suggests that elementary forms of the core EF components are present early during the preschool period. Changes in EF during the latter half of the preschool period appear to be due to the development of attention and integration of component EFs. Finally, the review outlines a number of areas that warrant further investigation if researchers are to move forward in understanding early EF development.

Brief report: data on the Stanford-Binet Intelligence Scales (5th ed.) in children with autism spectrum disorder.

The Fifth Edition of the Stanford-Binet Intelligence Scales (SB5; Roid, G. H. (2003). Stanford Binet intelligence scales (5th ed.). Itasca, IL: Riverside Publishing) is relatively new, with minimal published research on general populations and none with special populations. The present study provides information on the cognitive profiles of children with ASD (N=63) and on the whether the abbreviated battery is representative of the full scale. A high percentage of the children had significantly stronger nonverbal (vs. verbal) skills. This pattern was not related to Full Scale IQ, age or diagnostic subgroup. IQs derived from the abbreviated battery accounted for a large proportion of the variance in FSIQ relative to comparable abbreviated batteries. However, caution is warranted when using the abbreviated battery, as it misrepresents actual ability in a small percentage of cases.

The Autism Observation Scale for Infants: scale development and reliability data.

The Autism Observation Scale for Infants (AOSI) was developed to detect and monitor early signs of autism as they emerge in high-risk infants (all with an older sibling with an autistic spectrum disorder). Here we describe the scale and its development, and provide preliminary data on its reliability. Inter-rater reliability both for total scores and total number of endorsed items is good to excellent at 6, 12 and 18 months; reliability is more modest for individual items, particularly in 6-month-olds. Test-retest reliability of the AOSI at 12 months of age is within acceptable limits. Evidence that the AOSI provides reliable data is the first critical step towards evaluating its efficacy in distinguishing high-risk infants who develop ASD.

Early executive dysfunction in ASD: Simple versus complex skills.

Despite the strong evidence of executive function (EF) impairment in Autism Spectrum Disorder (ASD), findings in the preschool period have been inconsistent. Whereas some research has supported an early deficit, many studies have not found early differences in EF. The present study assessed simple and complex components of three EF abilities: working memory, inhibition, and shifting, using a novel battery, the Preschool EF Battery (PEFB; Garon, Smith & Bryson, Child Neuropsychology, 20, 713-736, 2014). Previous research has indicated that the PEFB is sensitive to age differences in typically developing (TD) children aged 18-60 months. Current participants were 34 preschoolers (M = 54.79 months) diagnosed with ASD and 255 TD preschoolers (M = 42.98 months). Results indicated significant differences between the two groups in the three EF abilities, but specific findings were moderated by mental and chronological age. The findings highlight the importance of testing simpler EF skills in very young children with ASD. Autism Res 2018, 11: 318-330. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Given that executive functions (EF) have been found to predict various outcomes such as academic ability and occupational success, sensitive early assessment is important. The current study suggests the presence of early EF deficits in preschool children with autism spectrum disorder. The study highlights the importance of considering how EF develops during early life in typically developing children in order to design sensitive EF measures.

Pivotal response treatment for preschoolers with autism spectrum disorder: Defining a predictor profile.

Behavioral characteristics of children with autism spectrum disorder (ASD) who respond positively to Pivotal Response Treatment (PRT) have been described previously, based on single-subject design research. The present study examined several such characteristics, as well as positive affect, as predictors of expressive language (EL) gains in a representative sample of preschoolers with ASD (n = 57) enrolled in a PRT-based community early intervention program. Children's cognitive ability, positive affect, and levels of appropriate toy contact measured at the start of intervention each contributed significantly to the prediction of EL outcomes. Together these variables accounted for 40% of the total outcome variance. In addition, a profile of increased EL ability, positive affect and appropriate toy contact, and decreased social avoidance and stereotyped and repetitive vocalizations was associated with greater gains during intervention. Results are discussed in relation to their implications for understanding both the variable treatment response documented in children with ASD and how to tailor treatment to optimize individual benefit. Autism Res 2018, 11: 153-165. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: The study examined behavior of 57 preschoolers who made the greatest and least gains from 1 year of a community Pivotal Response Treatment program. Using pre-treatment videos, we saw that children who made the most progress showed more language, positive affect, and appropriate interactions with toys, also less avoidance of people and fewer repetitive vocalizations. Behavior profiles can be used to match treatment to individual children's needs.