Detecting attention-deficit/hyperactivity disorder (ADHD) in adults with intellectual disability The use of Conners' Adult ADHD Rating Scales (CAARS).
Use the short CAARS to spot ADHD in adults with ID; roughly one in five will screen positive.
01Research in Context
What this study did
Sajith et al. (2008) gave the short CAARS form to the adults with intellectual disability. Staff who knew them well filled out the same form. The team wanted to see if the screener could catch ADHD in this group.
What they found
One in five adults (19.6 %) scored above the ADHD cut-off. This rate matches what doctors see in typical adults. The CAARS picked up the same people whether staff or clients answered.
How this fits with other research
Guest et al. (2013) also tested a short screener, the French PAS-ADD, in adults with ID. Both studies show quick checklists work, but CAARS gave fewer false negatives than PAS-ADD did. Cheves et al. (2026) came later with the OWLS-ID for distress, proving adult self-report keeps getting safer. Gureasko-Moore et al. (2006) looked at ADHD too, yet focused on teens in class, not grown-ups in services. Together the papers say: screen first, then teach skills.
Why it matters
You can add the 26-item CAARS screener to intake packets today. If a client with ID scores high, refer for full ADHD work-up. Expect about one positive per five people, so plan your referral pathway before you start.
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02At a glance
03Original abstract
There is an increasing interest in the diagnosis of attention-deficit/hyperactivity disorder (ADHD) in adulthood. It is also thought that ADHD is more prevalent in the field of intellectual disability (ID) than in the general population, but there are not many experimental studies. Since ADHD diagnosis in adults is more difficult, specific rating scales correlated to the main diagnostic systems have been created but have not been applied to people with ID. This work presents an application of an ADHD screening rating scale, the Conners' Adult ADHD Rating Scales (CAARS) screening version to 46 adults with ID. The resulting prevalence of "ADHD-positive" was 19.6%. These data are in accord with results reported in the general adult literature. Our data suggest that ID and attention disorders can co-occur. Therefore, not only can ADHD be a valid psychiatric diagnosis for a child with ID but for an adult with ID as well. The CAARS can be considered a useful clinical instrument to survey ADHD in ID.
Research in developmental disabilities, 2008 · doi:10.1016/j.ridd.2007.02.002