Association between parent reports of attention deficit hyperactivity disorder behaviours and child impulsivity in children with severe intellectual disability.
Parent checklists alone can over-label ADHD in kids with severe ID once you factor in mental age.
01Research in Context
What this study did
Bigham et al. (2013) asked parents to rate ADHD behaviors in children with severe intellectual disability. They then tested the same kids on a lab task that measures impulsivity. Finally they checked whether the parent scores matched the child’s actual impulsive choices.
The team also recorded each child’s developmental age. This let them see if mental age, not calendar age, changed the story.
What they found
Parent reports lined up with clinical interviews, so the adults agreed. But once the researchers held developmental age constant, the link between parent-rated ADHD and lab impulsivity vanished.
In plain words, the kids looked impulsive only until the team accounted for how old they were mentally.
How this fits with other research
Waldron et al. (2023) systematic review backs this up: attention in ID must be judged against mental age, not birthday. The review calls the global “ADHD in ID” idea a myth, echoing K et al.’s point.
Matson et al. (2011) earlier showed ADHD labels stick longer in kids with ID. K et al. now explains part of why—parents may be reading developmental delay as hyperactivity.
Ng et al. (2019) found the same rater-test split in autism: parents saw attention problems that objective tasks did not. The pattern crosses diagnoses—single informants over-flag.
Why it matters
Before you write “ADHD” in an ID treatment plan, pause. Collect mental-age data, run a quick delay-discount or choice task, and ask at least one other adult for ratings. Adjusting for developmental level can turn an “impulsive” child into a typical learner for their mental age, saving everyone from unneeded meds and wasted hours.
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02At a glance
03Original abstract
BACKGROUND: Although children with intellectual disability (ID) seemed to be at increased risk for Attention deficit hyperactivity disorder (ADHD)/hyperactivity problems when assessed with parent report questionnaires and clinical interviews, there has been little attention to the associations between parent reports and observed child behaviours. The purpose of the present study was to compare clinical symptoms and observed impulsivity in children with ID whose parents reported them as being relatively high and low in ADHD symptoms, and to examine whether any differences were associated with developmental level. METHODS: Parents of 28 children with ID completed a behaviour rating scale of hyperactivity symptoms. Parents were also interviewed using a robust clinical interview tool focused on hyperactivity symptoms. The children were all tested by an experimenter to measure their impulsive behaviour. RESULTS: Those children with clinical range scores on parent questionnaire ratings were also reported by parents to have more ADHD symptoms using a parent report clinical interview. Although these children were also more impulsive on an experimental task, when children's developmental ages were statistically controlled impulsivity differences disappeared. CONCLUSIONS: Parent reports of ADHD symptoms in children with ID may be positively associated with data derived using clinical interview methods, but they may be less sensitive to developmental expectations when compared with observed child behaviour. Practical implications include the need for multiple sources of information and normative data for children with ID on simple experimental tasks that can be used to aid diagnosis of ADHD in clinical settings.
Journal of intellectual disability research : JIDR, 2013 · doi:10.1111/j.1365-2788.2011.01522.x