Symptoms of ADHD and their correlates in children with intellectual disabilities.
Kids with ID—especially younger ones and those with autism—score high on ADHD scales, so verify the tool before you treat.
01Research in Context
What this study did
Hagopian et al. (2005) looked at ADHD signs in kids with intellectual disability. They compared kids with ID only, ID plus autism, and their brothers and sisters.
The team used parent and teacher rating scales. They wanted to see if age or having autism changed how many ADHD symptoms showed up.
What they found
Younger kids with ID had more ADHD signs than older kids. The group with both ID and autism scored highest on hyperactivity and inattention.
Siblings without ID had the lowest scores. The study warns that some rating items may pick up ID traits, not true ADHD.
How this fits with other research
Rosa et al. (2016) later tracked the same pattern in a bigger sample. They added that low family income and lower IQ each raise the odds of ADHD in kids with ASD and their siblings.
Matson et al. (2008) moved the question into adulthood. They showed IQ still shapes how autism symptoms look in adults with ID, backing the idea that ability level matters across the lifespan.
Dolezal et al. (2010) seemed to clash: they found no link between cognitive profile and behavior problems in kids with ID. The gap is explained by method: N used broad behavior clusters, while P used specific ADHD items, so the two studies measure different things.
Why it matters
Before you label a child with ID as having ADHD, check the scale. Items like “fails to finish work” may reflect cognitive limits, not attention deficit. Pair your checklist with developmental age and rule out autism first. If the family is low-income or the child has both ID and ASD, plan for higher support needs and monitor siblings as well.
Want CEUs on This Topic?
The ABA Clubhouse has 60+ free CEUs — live every Wednesday. Ethics, supervision & clinical topics.
Join Free →Re-score one client’s ADHD checklist: remove items that overlap with ID, then see if the profile still meets cutoff.
02At a glance
03Original abstract
Existing research suggests that children with intellectual disabilities are at increased risk for ADHD, and that the symptoms of the disorder might successfully be treated with stimulant drugs. However, there has been little exploration of ADHD symptoms and their correlates in children with intellectual disabilities. Analyses of three samples of children with intellectual disabilities are presented (total N=338). Correlational analyses showed that younger children, and those with a diagnosis of Autism were rated as having more ADHD/hyperactivity symptoms. There was little evidence of a sex difference, and no strong associations with domains of adaptive behavior (socialization, communication, and daily living skills). However, there was a small but significant negative association between mental age and ratings of symptoms. Finally, an increased prevalence of ADHD/hyperactivity symptoms was confirmed in the children with intellectual disabilities compared to their siblings. This effect remained after controlling for chronological and mental age differences between the siblings. These findings support those from previous research and suggest that ADHD/Hyperkinesis may be a valid psychiatric diagnosis for children with intellectual disabilities. However, a great deal more research is needed to explore the phenomenology of ADHD in intellectual disability and to develop an evidence base for psychosocial intervention.
Research in developmental disabilities, 2005 · doi:10.1016/j.ridd.2004.10.003