Support for a dimensional view of autism spectrum disorders in toddlers

We examined whether clinically distinct subgroups can be derived from a sample of toddlers (n = 186) who failed the Modified Checklist for Autism in Toddlers, received a comprehensive clinical evaluation, and were diagnosed with an autism spectrum disorder (ASD). Three subgroups emerged from cluster analysis distinguished by (a) social, communication, and intellectual skills and (b) the rate and intensity of repetitive behaviors and abnormal sensory response. Preoccupations, compulsions, and rituals did not distinguish resultant subgroups. These results support a dimensional diagnostic view of ASDs in toddlers since subgroup differences were based on symptom severity rather than different symptom profiles. Results also identify specific types and levels of behavioral deficit relevant to toddler populations. Implications for early diagnosis are discussed. Keywords Autism spectrum disorders (ASDs) * Early identification * Early diagnosis * Cluster analysis
Introduction Children with autism spectrum disorders (ASDs) comprise a heterogeneous group that shows diverse levels of social, communication, behavioral, and intellectual development. Consequently, attempts to discover common features of ASDs [...]