Objective The primary aim of the present study was to evaluate the validity of proposed DSM-5 criteria for Autism Spectrum Disorder (ASD). Method We analyzed symptoms from 14,744 siblings (8,911 ASD; 5,863 non-ASD) included in a national registry, the Interactive Autism Network. Youth aged 2–18 were included if at least one child in the family was diagnosed with ASD. Caregivers reported symptoms using the Social Responsiveness Scale and the Social Communication Questionnaire. The structure of autism symptoms was examined using latent variable models that included categories, dimensions, or hybrid models specifying categories and sub-dimensions. Diagnostic efficiency statistics evaluated the proposed DSM-5 algorithm in identifying ASD. Results A hybrid model that included both a category (ASD vs. non-ASD) and two symptom dimensions (social communication/interaction and restricted/repetitive behaviors) was more parsimonious than all other models and replicated across measures and sub-samples. Empirical classifications from this hybrid model closely mirrored clinical ASD diagnoses (90% overlap), implying a broad ASD category distinct from non-ASD. DSM-5 criteria had superior specificity relative to DSM-IV-TR criteria (.97 vs. .86), however sensitivity was lower (.81 vs. .95). Relaxing DSM-5 criteria by requiring one less symptom criterion increased sensitivity (.93 vs. .81), with minimal reduction in specificity (.95 vs. .97). Conclusions Results supported the validity of proposed DSM-5 criteria for ASD as provided in Phase I field trials criteria. Increased specificity of DSM-5 relative to DSM-IV-TR may reduce false positive diagnoses, a particularly relevant consideration for low base rate clinical settings. Phase II testing of DSM-5 should consider a relaxed algorithm, without which as many as 12% of ASD-affected individuals, particularly females, will be missed. Relaxed DSM-5 criteria may improve identification of ASD, decreasing societal costs through appropriate early diagnosis and maximizing intervention resources.

Recent eye tracking studies of face processing have produced differing accounts of how and whether children with autism differ from their typically developing peers. The two groups' gaze patterns appear to differ for dynamic videos of social scenes, but not for static photos of isolated individuals. The present study replicated and extended previous research by comparing the gaze patterns of individuals with and without autism for four types of stimuli: social dynamic, social static, isolated dynamic, and isolated static. Participants with autism differed from their typically developing peers only for social-dynamic stimuli; fixation durations were decreased for eye regions and increased for body regions. Further, these fixation durations predicted scores on a measure of social responsiveness. These findings reconcile differences in previous reports by identifying the specific social and dynamic task components associated with autism-related face processing impairments.

BACKGROUND: Pediatricians, neurologists, and geneticists are important sources for autism surveillance, screening, and referrals, but practical time constraints limit the clinical utility of behavioral observations. We analyzed behaviors under favorable conditions (ie, video of autism evaluations reviewed by experts) to determine what is optimally observable within 10-minute samples, asked for referral impressions, and compared these to formal screening and developmental testing results.METHODS: Participants (n = 42, aged 15 to 33 months) were typically developing controls and children who screened positive during universal autism screening within a large community pediatric practice. Diagnostic evaluations were performed after screening to determine group status (autism, language delay, or typical). Licensed psychologists with toddler and autism expertise, unaware of diagnostic status, analyzed two 10-minute video samples of participants' autism evaluations, measuring 5 behaviors: Responding, Initiating, Vocalizing, Play, and Response to Name. Raters were asked for autism referral impressions based solely on individual 10-minute observations. RESULTS: Children who had autism showed more typical behavior (89% of the time) than atypical behavior (11%) overall. Expert raters missed 39% of cases in the autism group as needing autism referrals based on brief but highly focused observations. Significant differences in cognitive and adaptive development existed among groups, with receptive language skills differentiating the 3 groups.CONCLUSIONS: Brief clinical observations may not provide enough information about atypical behaviors to reliably detect autism risk. High prevalence of typical behaviors in brief samples may distort clinical impressions of atypical behaviors. Formal screening tools and general developmental testing provide critical data for accurate referrals. WHAT'S KNOWN ON THIS SUBJECT:Behavioral observations influence a clinician' s decision to diagnose or refer, and may even override formal screening results. In the case of autism spectrum disorder, an expected rate of atypical behavior during the span of a medical visit is unknown. WHAT THIS STUDY ADDS:We are the first to quantify the high base rates of typical behavior in young children who have autism and language delay. When observation times are brief, the preponderance of typical behaviors may negatively impact referral decision accuracy.

Objective: The primary aim of this study was to develop and validate eye tracking-based measures for estimating autism spectrum disorder (ASD) risk and quantifying autism symptom levels. Method: Eye tracking data were collected from youth during an initial evaluation visit, with administrators blinded to all clinical information. Consensus diagnoses were given by the multidisciplinary team. Participants viewed a 5- minute video that included 44 dynamic stimuli from 7 distinct paradigms while gaze was recorded. Gaze metrics were computed for temporally-defined regions-of-interest. Autism risk and symptom indices aggregated gaze measures showing significant bivariate relationships with ASD diagnosis and Autism Diagnostic Observation Schedule 2 (ADOS-2) symptom severity levels in a training sample (75%, n=150). Receiver operating characteristic curve analysis and non-parametric correlations were used to cross-validate findings in a test sample (25%; n=51). Results: Most children (n=201, 92%) completed a valid eye tracking assessment (ages 1.6–17.6; 80% male; ASD n=91, non-ASD n=110). In the test sub-sample, the autism risk index had high accuracy for ASD diagnosis (area under the curve [AUC]=.86, 95%CIs=.75-.95), while the autism symptom index was strongly associated with ADOS-2 total severity scores (r=.41, p<.001). Validity was not substantively attenuated after adjustment for language, non-verbal cognitive ability, or other psychopathology symptoms (r=.40-.67, p>.001). Conclusion: Eye tracking measures appear to be useful quantitative, objective measures of ASD risk and autism symptom levels. If independently replicated and scaled for clinical use, eye tracking-based measures could be used to inform clinical judgment regarding ASD identification and to track autism symptom levels.