Repetitive behavior and restricted interests in young children with autism: comparisons with controls and stability over 2 years.

Restricted, repetitive and stereotyped patterns of behavior, interests and activities [RRBs] are among the core symptoms of autism spectrum disorders (ASD). Previous studies have indicated that RRBs differentiate ASD from other developmental disorders and from typical development. This study examined the presentation of RRBs as reported on the Repetitive Behavior Scale-Revised, a caregiver report, in children with ASD [separated into autism and Pervasive Developmental Disorder-Not Otherwise Specified groups] compared with children with nonspectrum developmental delays or typical development. We examined the role of age, cognitive functioning, sex and social communication impairment as they relate to RRBs. The stability of RRBs in children with autism was also examined over the course of 2 years. Results of the study confirmed that the amount and type of RRBs differs by diagnosis. Age, cognitive functioning, sex and social-communication impairment were not significant correlates. Among children with autism, RRBs remained stable over time.

Multisite study of new autism diagnostic interview-revised (ADI-R) algorithms for toddlers and young preschoolers.

Using two independent datasets provided by National Institute of Health funded consortia, the Collaborative Programs for Excellence in Autism and Studies to Advance Autism Research and Treatment (n = 641) and the National Institute of Mental Health (n = 167), diagnostic validity and factor structure of the new Autism Diagnostic Interview (ADI-R) algorithms for toddlers and young preschoolers were examined as a replication of results with the 2011 Michigan sample (Kim and Lord in J Autism Dev Disord 42(1): 82-93, 2012). Sensitivities and specificities and a three-factor solution were replicated. Results suggest that the new ADI-R algorithms can be appropriately applied to existing research databases with children from 12 to 47 months and down to nonverbal mental ages of 10 months for diagnostic grouping.

The ADOS calibrated severity score: relationship to phenotypic variables and stability over time.

Measurement of the severity of autism at a single time point, and over time, is a widespread challenge for researchers. Recently, Gotham, Pickles, and Lord published a severity metric (calibrated severity scores; CSS) that takes into account age and language level and is based on raw total scores of the Autism Diagnostic Observation Schedule (ADOS), a standardized measure commonly used in autism diagnosis. The present study examined psychometric characteristics of the CSS compared to raw scores in an independent sample of 368 children aged 2 to 12 years with autism, pervasive developmental disorder-not otherwise specified (PDD-NOS), non-spectrum delay, or typical development. Reflecting the intended calibration, the CSS were more uniformly distributed within clinical diagnostic category and across ADOS modules than were raw scores. Cross-sectional analyses examining raw and severity scores and their relationships to participant characteristics revealed that verbal developmental level was a significant predictor of raw score but accounted for significantly less variance in the CSS. Longitudinal analyses indicated overall stability of the CSS over 12 to 24 months in children with autism. Findings from this study support the use of the CSS as a more valid indicator of autism severity than the ADOS raw total score, and extend the literature by examining the stability over 12 to 24 months of the CSS in children with ASD.

Brief report: symptom onset patterns and functional outcomes in young children with autism spectrum disorders.

This study examined the relationship between onset status and current functioning using a recently proposed onset classification system in 272 young children with autism spectrum disorder (ASD). Participants were classified into one of the following groups, based on parent report using the Autism Diagnostic Interview--Revised: Early Onset (symptoms by 12 months, no loss), Delay + Regression (symptoms by 12 months plus loss), Plateau (no early symptoms or loss), and Regression (no early symptoms, followed by loss). Findings indicate that current functioning does not differ according to onset pattern, calling into question the use of onset categorizations for prognostic purposes in children with ASD.

Communicative acts of children with autism spectrum disorders in the second year of life.

PURPOSE: To examine the communicative profiles of children with autism spectrum disorders (ASD) in the second year of life. METHOD: Communicative acts were examined in 125 children 18 to 24 months of age: 50 later diagnosed with ASD; 25 with developmental delays (DD); and 50 with typical development (TD). Precise measures of rate, functions, and means of communication were obtained through systematic observation of videotaped behavior samples from the Communication and Symbolic Behavior Scales Developmental Profile (A. Wetherby & B. Prizant, 2002). RESULTS: Children with ASD communicated at a significantly lower rate than children with DD and TD. The ASD group used a significantly lower proportion of acts for joint attention and a significantly lower proportion of deictic gestures with a reliance on more primitive gestures compared with the DD and TD groups. Children with ASD who did communicate for joint attention were as likely as other children to coordinate vocalizations, eye gaze, and gestures. Rate of communicative acts and joint attention were the strongest predictors of verbal outcome at age 3. CONCLUSION: By 18 to 24 months of age, children later diagnosed with ASD showed a unique profile of communication, with core deficits in communication rate, joint attention, and communicative gestures.

Social communication profiles of children with autism spectrum disorders late in the second year of life.

This study examined social communication profiles from behavior samples videotaped between 18 and 24 months of age in three groups of children: 50 with autism spectrum disorders (ASD), 23 with developmental delays (DD), and 50 with typical development (TD). The ASD group scored significantly lower than the DD group on 5 social communication measures and the TD group on all 14 measures, indicating distinct profiles late in the second year. Understanding was the strongest predictor of developmental level and behavior regulation and inventory of gestures were the strongest predictors of autism symptoms at 3 years of age. The predictive relations suggest five pivotal skills late in the second year that have a cascading effect on outcomes of children with ASD.

Prelinguistic predictors of language outcome at 3 years of age.

PURPOSE: The purpose of this study was to examine the predictive validity of a collection of prelinguistic skills measured longitudinally in the 2nd year of life to language outcome in the 3rd year in children with typical language development. METHOD: A collection of prelinguistic skills was assessed in 160 children early (M = 14.31 months; SD = 1.36) and late (M = 19.76 months; SD = 1.16) in their 2nd year by using the Communication and Symbolic Behavior Scales Developmental Profile Behavior Sample (A. Wetherby & B. Prizant, 2002). The relation between the prelinguistic skills and the receptive and expressive language near the 3rd birthday was examined. RESULTS: Significant correlations were observed between many prelinguistic skills and language outcome. Regression analyses indicated that comprehension both early and late contributed unique variance to receptive and expressive language outcome. In addition, early in the 2nd year, inventory of conventional gestures contributed uniquely to receptive language outcome, and acts for joint attention contributed uniquely to expressive outcome. Late in the 2nd year, inventory of consonants contributed uniquely to expressive outcome. CONCLUSIONS: The findings demonstrate continuity between prelinguistic and linguistic skills and how individual differences in a number of prelinguistic skills contribute collectively and uniquely to language outcome in typically developing children.