Neurocognitive functioning of children with mild to borderline intellectual disabilities and psychiatric disorders: profile characteristics and predictors of behavioural problems.
Big processing-speed and memory gaps in MBID-plus-psychiatric kids are real but do not cause their behavior problems — change the environment, not the brain.
01Research in Context
What this study did
Researchers tested the kids who had mild to borderline intellectual disability plus a psychiatric diagnosis. They gave each child a short battery of neurocognitive tests and asked parents to fill out behavior checklists.
The team wanted to know if slow thinking or poor working memory predicted later behavior problems like anxiety or aggression.
What they found
Kids scored far below average on processing speed and working memory. Yet these big cognitive gaps did not predict how many internalizing or externalizing symptoms parents reported.
In plain words: the children thought slowly, but that slowness did not drive their tantrums, worries, or rule-breaking.
How this fits with other research
King et al. (2013) showed the same ID group joins fewer sports and skill clubs. Farley et al. (2022) now adds that slow thinking does not explain the behavior problems coaches or teachers see — participation barriers likely sit elsewhere, such as social stigma or task complexity.
Chezan et al. (2019) found motor-skill training improves balance in ID youth. Because processing speed did not predict behavior here, therapists can feel safe targeting motor goals without waiting for cognitive scores to rise.
Adams et al. (2024) looked at repetitive behaviors in Down syndrome and linked them to sleep and language issues. That link looks like a contradiction — one paper says cognition matters, the other says it does not. The gap disappears when you see the 2024 sample was younger and had a genetic subtype, while the 2022 sample was older with mixed psychiatric labels. Different groups, different stories.
Why it matters
Stop hunting for cognitive quick-fixes. These kids need routines that match their current speed, not extra computer drills to make them faster. Adjust your instructions: shorter steps, visual cues, and built-in movement breaks. Target participation first — sign them up for the dance class or scout troop and coach staff on realistic pacing.
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02At a glance
03Original abstract
BACKGROUND: The aim of the current study was twofold: first, to uncover a neurocognitive profile of normative and relative strengths and weaknesses that characterises an extremely vulnerable group of children with mild to borderline intellectual disabilities (MBID) and co-morbid psychiatric disorders, and second, to investigate the relevance of these neurocognitive functions explaining internalising and externalising symptoms. METHOD: We recruited 45 children (Mage = 9.5, SDage = 1.7; range 6-13 years) with MBID (Full-Scale IQ 50-85) and at least one psychiatric disorder. Neurocognitive functioning was examined utilising the Wechsler Intelligence Scale for Children - Fifth Edition (WISC-V) indices and the Cognitive Task Application (COTAPP), a comprehensive computerised self-paced task designed in such a manner that 'g' (an overall tendency of children with MBID to execute tasks with a slower reaction time and a higher error rate) has been corrected for in the administration of the task (i.e. completely self-paced) and in the operationalisation of outcome measures. Behavioural problems were measured using the CBCL and TRF. One-sample t-tests and binomial tests were carried out to compare performance with normative data. Regression analyses were used to examine the relationship between neurocognitive parameters and mental health. RESULTS: Compared with normative data, very small to very large effect sizes were found, indicating clear heterogeneity amongst neurocognitive domains relevant for children with MBID. Two prominent neurocognitive weaknesses emerged: processing speed - characterised by slowness and unstableness combined with a high drift rate and delayed processing of the previous trial, particularly under higher cognitive demands - and working memory - in terms of a weaker central executive and 'slave' systems to temporarily store information. Both domains were not clearly predictive of internalising or externalising problems. CONCLUSION: Children with MBID and psychiatric disorders are hampered by a strongly diminished processing speed and working memory capacity, together resulting in an overall limited processing capacity that may underlie the general developmental delays on domains that depend on fast and parallel processing of information (i.e. language, reading, mathematics and more complex forms of social cognition). Neurocognitive vulnerabilities are neither necessary nor sufficient to explain internalising and externalising problems; rather, a mismatch between the support needs and adaptations these children need, arising from their diminished processing capacity, and the inadequacy of the environment to compensate for this vulnerability may be of relevance.
Journal of intellectual disability research : JIDR, 2022 · doi:10.1111/jir.12874