Challenging behavior can occur in as many as half of individuals with ID; and 5–10% of these individuals’ behavioral challenges are characterized as severe. The prevalence of SIB among children with ASD is reported to exceed 28%. Elopement also puts a child at risk for serious harm or death; and one recent parent survey indicated that 49% of children with ASD engaged in elopement after the age of 4 years. Among those that reported one or more instances of elopement, nearly one quarter were in danger of drowning, and over two-thirds were at risk of being struck by a motor vehicle. Like findings on other forms of challenging behavior, the severity of the child’s disability was associated with higher rates of elopement.
In addition, the prevalence of psychiatric and behavioral disorders is elevated among youth with ASD. In community samples, 70% of youth with ASD have at least one psychiatric disorder, a prevalence that is 3.5 times greater than in the non-ASD population (Simonoff et al., 2008). The prevalence of psychopathology is even higher in clinical samples with 95% and 74% of youth with ASD exhibiting three and five disorders, respectively (Joshi et al., 2010).
