What is the research about?

Children and teenagers with Intellectual Disability (ID) are known to be 3 to 4 times more likely than their typically developing peers to have mental health or behavioural problems. The presence of aggression, serious behavioural problems, depression, and anxiety all interfere with a young person’s ability to engage in school, recreation, work or education and cause serious stress to the child and their family. This study looked at the development over time of mental health and behaviour problems in a group of children and teenagers with ID.

What did the researchers do?

The researchers analyzed the data of over 500 children and teenagers with ID, aged 5 to 19.5 years, who had taken part in the Australian Child to Adult Development Study over a period of 14 years. As part of the research, parents or caregivers filled out a questionnaire about any behavioural or emotional disturbance seen in their child that was very abnormal, caused distress to the parent, impaired the child’s daily functioning, or went beyond anything likely to result from the ID itself.

What did the researchers find?

At the beginning of the study, the researchers found that 41% of the children and teenagers had a major psychiatric disorder or behavioural problem. The severity of their mental health condition at the beginning of the study was not related to whether their ID was mild or severe. These levels decreased slowly over ten years, more so in girls and in those with mild ID, until the percentage of young people with psychopathology decreased to 31%. During the study period, only 10% of the children and teenagers received any psychiatric help.

Take home message

The authors of this study emphasized that rates of mental health problems in young people with ID are considerable and that they persist without proper treatment. It is important that parents, caregivers, and professionals recognize the possibility that some of the difficult behaviours they see in children and teenagers with ID could be mental health problems. It is possible that with proper diagnosis and treatment some of the problem symptoms and behaviours could be reduced, thus improving the quality of life of these young people and their families.


The original Research Report was written by S. L. Einfeld and associates of the Australian Child to Adult Development Study and published in JAMA in 2006.