Autism spectrum disorders: Core features, associated characteristics, and diagnostic considerations.

Core features of autism spectrum disorder (ASD) were examined from different perspectives. In the first study, children with ASD were compared to children with fetal alcohol spectrum disorder (FASD) in order to isolate social deficits that are most unique to ASD. Difficulties in initiating social interaction, sharing affect, and using nonverbal communication were common in children with ASD but rare in children with FASD. Socially inappropriate behaviors and difficulty with peers were common in children with ASD and children with FASD. These findings suggest that whereas propensity for social interaction may be a differentiating factor between children with ASD and those with non-spectrum disorders, social appropriateness may be less diagnostically discriminative. In the second study, the relationship between restricted and repetitive behaviors (RRBs) and nonverbal IQ (NVIQ) was examined in a large group of children with ASD. RRBs were prevalent in children with ASD of different levels of functioning, but certain behaviors were more common either in lower or higher functioning children. These results lend some support to the idea of different classes of RRBs. Whereas sensory-motor RRBs were related to age and NVIQ, insistence on sameness RRBs were less clearly related to developmental level. Additionally, there was an interactive effect of NVIQ and chronological age on the presence of RRBs; lower NVIQ was more closely associated with a higher prevalence of certain RRBs in older children than in younger children. In the third study, mothers of 9-year-old children with ASD completed interviews about the perceived negative impact of having a child with ASD. Several parent, child, and family variables were examined as potential predictors of perceived negative impact. African American mothers reported significantly lower levels of perceived negative impact than Caucasian mothers. Mothers of children with lower adaptive behavior scores and more RRBs also reported higher perceived negative impact, as did mothers who reported having little or no social support.PhDClinical psychologyPsychologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/125963/2/3224820.pd