Indicators of intellectual disabilities in young children with autism spectrum disorders.

Mélia et al. (2015) looked at preschoolers who were starting ABA. They wanted to know how many also had intellectual disability (ID).

The team used standard tests to check IQ and adaptive skills. They split the kids into mild or moderate ID groups.

About 1 in 3 preschoolers with ASD met criteria for ID. Of those, 60% had mild ID and 40% had moderate ID.

Boys and girls showed the same rate. The finding held no matter how severe the autism symptoms looked.

Anne-Schweizer et al. (2013) found the exact same 36% ID rate in a community sample two years earlier. The match shows the number is solid across clinic and public-health settings.

Etyemez et al. (2022) widened the lens. They showed that kids with ASD+ID are more likely to have extra developmental conditions like epilepsy or motor delays. Use their list when you plan multidisciplinary assessments.

Salazar et al. (2015) add another layer. In the same preschool age range they found 90% of kids with ASD had at least one extra psychiatric diagnosis, such as ADHD or anxiety. ID plus psychiatric comorbidity is the rule, not the exception.

When a three-year-old walks into your session with an ASD diagnosis, flip a mental coin: one side says ID is also present. Plan your baseline assessments to include IQ, adaptive skills, language, and common psychiatric screens. Write goals that build on visual strengths while giving extra support for abstract language and self-care. Share the full profile with speech, OT, and medical teams so everyone targets the same skill gaps.