Intellectual disability and co-occurring mental health and physical disorders in aggressive behaviour.
Every added health problem—mental or physical—raises the chance of aggression in adults with mild–moderate ID.
01Research in Context
What this study did
de Kuijper et al. (2014) asked 296 adults with mild–moderate intellectual disability about their health.
They counted how many physical or mental health problems each person had. Then they checked who showed aggressive behaviour in the past year.
What they found
More health problems meant higher odds of aggression. The link held for both physical illnesses and mental health disorders.
How this fits with other research
Reiss et al. (1993) saw the same pattern years earlier. They found adults with ID and depression were about four times more likely to be aggressive.
Myrbakk et al. (2008) and Casey et al. (2009) repeated the finding. All three studies show psychiatric symptoms raise aggression risk.
Bellon-Harn et al. (2020) went further. They listed four common triggers—frustration, pain, change, and defense—and tied them to both psychiatric and sleep problems. The 2014 paper adds the simple rule: count the total illnesses, not just one.
Why it matters
When an adult with ID starts hitting or yelling, do a quick health tally. Note every diagnosis—diabetes, epilepsy, depression, anxiety. Each extra condition raises risk, so share the list with the medical team. Treating the illness often lowers the behaviour.
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02At a glance
03Original abstract
BACKGROUND: Mental and physical health problems are more prevalent among individuals with an intellectual disability (ID) than in the general population. Studies suggest that there may be significant associations between these co-occurring disorders and aggressive behaviour, but few studies have taken into account multiple mental and physical problems, as well as their level of severity. OBJECTIVES: The main goal of this study was to identify the associations between different types of aggressive behaviour and various types of physical and mental health problems. METHODS: These associations were explored through a cross-sectional study of 296 adult men and women with mild or moderate ID living in the community and receiving ID services. Information was gathered through interviews with ID participants, case managers and file review. RESULTS: The results show that individuals with ID who have more mental and physical health problems have higher odds of displaying aggressive behaviour than those with fewer and less severe physical health problems. DISCUSSION: These results can help guide future prevention and intervention strategies for persons with ID who display aggressive behaviour or who are at risk of become aggressive.
Journal of intellectual disability research : JIDR, 2014 · doi:10.1111/jir.12080