A general practice-based study of the relationship between indicators of mental illness and challenging behaviour among adults with intellectual disabilities.
Mental illness and low daily living skills together raise challenging behavior in adults with ID—screen for both.
01Research in Context
What this study did
Casey et al. (2009) looked at adults with intellectual disability who visited their regular doctor. They checked if those with mental health problems also showed more hitting, screaming, or self-injury.
The team also asked how well each person could do daily tasks like dressing or counting. They wanted to see if low daily living skills made the mental health–behavior link stronger.
What they found
Adults with ID who had more mental health symptoms also showed more challenging behavior. The link was strongest in people who needed the most help with everyday tasks.
In plain words: when psychiatric illness is present and adaptive skills are low, behavior problems increase.
How this fits with other research
Myrbakk et al. (2008) found the same pattern one year earlier: adults with ID plus behavior problems carried more psychiatric symptoms. Their data foreshadowed this 2009 result.
Balboni et al. (2020) seems to disagree. In their severe–profound group, better daily skills went hand-in-hand with more challenging behavior. The clash disappears when you see they studied highly comorbid, institutionalized adults—different from the GP patients here.
BøRge et al. (2008) also push back. Psychiatric labels did not predict the reason behaviors happened (attention, escape, etc.). So screen for mental health, but still run your functional analysis.
Why it matters
If an adult with ID starts hitting or screaming, first rule out psychiatric illness—especially if the person also struggles with dressing, cooking, or toileting. A quick mood or anxiety screen can guide you to the right referral and keep behavior plans from missing a treatable cause.
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02At a glance
03Original abstract
BACKGROUND: Existing studies tend to show a positive association between mental illness and challenging behaviour among adults with intellectual disabilities (ID). However, whether the association is direct or artefactual is less clear. The purpose was to explore the association between psychiatric status and level of challenging behaviour, while controlling for adaptive behaviour and occurrence of autistic spectrum disorders. METHODS: Data were collected on the age, gender, adaptive and challenging behaviour, social impairment and psychiatric status of 312 adults with ID. Participants were divided according to psychiatric status, group equivalence in adaptive behaviour and the presence of autistic spectrum disorders achieved, and differences in challenging behaviour explored. In addition, multiple regression was used to examine the association between psychiatric status and challenging behaviour after controlling for other participant characteristics and to test whether the interaction between psychiatric status and adaptive behaviour added significantly to explanation. RESULTS: Challenging behaviour was higher among participants meeting threshold levels on the psychiatric screen. The regression analysis confirmed the association and demonstrated an interaction between total score on the psychiatric screen and level of adaptive behaviour. This moderated effect showed the relationship between psychiatric status and challenging behaviour to be stronger at lower adaptive behaviour. CONCLUSIONS: This study reinforces previous findings that psychiatric morbidity among people with ID is associated with higher levels of challenging behaviour and supports predictions that this association is more pronounced for people with severe ID. The precise nature and causal direction of the association requires further clarification. However, the understanding of how psychiatric problems might contribute to challenging behaviour needs to be part of the clinical appreciation of such behaviour.
Journal of intellectual disability research : JIDR, 2009 · doi:10.1111/j.1365-2788.2008.01131.x