Behavioral problems in children with autism spectrum disorder with and without co-occurring intellectual disability.

Highlights • Children with co-occurring ASD and ID were evaluated and diagnosed earlier than children with ASD only. • Compared to children with ASD only, those with ASD + ID were at greater risk of self injury, abnormal fear response, and eating abnormalities. • Self injury, abnormal fear response and eating abnormalities increased with increasing levels of cognitive impairment. • Mood and sleep abnormalities among children with ASD declined with increasing levels of cognitive impairment. • Degree of cognitive impairment was not consistently related to aggression, inattention/hyperactivity, temper tantrums, argumentative/oppositional behavior, or sensory problems in children with ASD. Abstract Background Autism spectrum disorder (ASD), intellectual disability (ID), and behavioral problems commonly co-occur, leading to increased impairment, diagnostic confusion, and treatment delays. Using data from a large surveillance population of children with ASD, the objectives of the present study were to compare the relative risk of common behavioral problems in children with ASD, with and without co-occurring intellectual disability. Methods Data from the Autism and Developmental Disabilities Monitoring (ADDM) Network (2006–2010) on 9378 8-year-old children who met case definition for ASD and had cognitive test scores and information on behavioral problems were analyzed using frequency measures, risk ratios, chi-squared tests, and trend tests. Results Children with ASD with and without ID had on average six co-occurring behavioral problems. The relative risk (RR) of self-injurious behaviors, unusual fear responses, and eating abnormalities increased with increasing cognitive impairment among children with ASD and ID (all p< 0.001). Conversely, RR of mood (p< 0.001) and sleep abnormalities (p= 0.013) declined with increasing levels of cognitive impairment. Conclusions Children with ASD and ID are at greater risk of some behavioral problems and lower risk of others as compared to children with ASD only. Successful interventions depend on understanding the complex interactions between co-occurring neurodevelopmental and behavioral problems. [ABSTRACT FROM AUTHOR]