Attention-deficit/hyperactivity disorder among children with and without intellectual disability: an examination across time.
Expect ADHD to last longer in children with ID, so screen early and keep supports in place.
01Research in Context
What this study did
Matson et al. (2011) watched two groups of kids from age 5 to 8. One group had intellectual disability. The other group was typically developing.
They checked each year to see how many kids met the rules for ADHD. They wanted to know if ADHD stayed longer in kids with ID.
What they found
More kids with ID kept their ADHD label every year. The typical kids often lost the label as they grew.
Both groups followed the same shape of change, but the ID group stayed higher. Early screening is key.
How this fits with other research
Aman et al. (2002) followed low-IQ kids for four extra years. They also saw ADHD stick around and new problems pile on. The two studies line up like stairs across time.
McClain et al. (2017) looked at older kids and added autism. They found ADHD looked milder when ID or ASD was also present. This seems to clash with L et al., but the difference is method: Brunson used one-time ratings, while L et al. watched the same kids yearly. Cross-sectional snapshots can miss the slow drag of symptoms.
Waldron et al. (2023) reviewed dozens of papers and warned that attention in ID should be judged against mental age, not birthday age. Their point supports L et al.: if you expect birthday-level focus, you will over-label ADHD in ID.
Why it matters
If you work with kids who have ID, plan for ADHD to stay. Start supports early and keep them in place. Use mental-age norms when you score rating scales so you do not mistake slow development for a new disorder. Share this long view with teachers and families so they do not drop helpful strategies too soon.
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02At a glance
03Original abstract
BACKGROUND: Children with intellectual and developmental disabilities are at heightened risk for mental disorders, and disruptive behaviour disorders appear to be the most prevalent. The current study is a longitudinal examination of attention-deficit/hyperactivity disorder (ADHD) among children with and without intellectual disability (ID) across ages 5 to 8. METHOD: We assessed 228 5-year-old children, 87 with ID and 141 with typical development (TD), for clinical diagnoses using a structured interview. These interviews were conducted with mothers annually from child age 5 to 8. RESULTS: Attention-deficit/hyperactivity disorder was over 3 times as prevalent in the ID group as in the TD group across ages 5, 6, 7 and 8. The diagnosis of ADHD tended to emerge earlier and was more stable in the ID group; however, the total number and relative frequency of ADHD symptoms endorsed appeared to be similar within the two groups across time. With respect to the developmental course, the trajectories of ADHD inattentive and hyperactive/impulsive symptoms over time were similar in the two groups. DISCUSSION: Children with ID appear to be at heightened risk for ADHD and they may experience a longer and more persistent course of the disorder. These findings highlight the need for making interventions available for early treatment of this condition in children with ID.
Journal of intellectual disability research : JIDR, 2011 · doi:10.1111/j.1365-2788.2011.01416.x