Touching Lives - October 2010
Pioneering ADHD and learning disabilities study uncovers genetic link
Three in 100 children have a learning disability and 30–50 per cent of these have a psychiatric disorder, usually attention deficit hyperactivity disorder (ADHD). Not much was known about the cause of ADHD in children with a learning disability as they were almost always excluded from research. But the first study of its kind, funded by Action Medical Research with the generous support of The Baily Thomas Charitable Fund, has identified genetic factors associated with these cases.
Project leader Professor Anita Thapar and her team found that subtle genetic anomalies are important in ADHD but especially so when accompanied by a learning disability. This means there is a biological reason for ADHD in children with a learning disability. The findings suggest that ADHD may be more of a neurodevelopmental disorder rather than a behavioural one.
This better understanding of the biological reasons for ADHD in children with a learning disability underscores the importance of recognising and treating the combined condition. It suggests children with ADHD and a learning disability may benefit from clinical genetics advice too. The study also highlighted that children with a learning disability should not be excluded from research into ADHD and that they should be considered for ADHD screening.
The findings of this project, completed in March, have already made an impact: there are now better links between child mental health, paediatric and clinical genetics services. In particular, child and adolescent mental health services in Wales now provide care for children with a learning disability and mental health problems. Also, clinical practice should see improved screening for ADHD in children with a learning disability, specifically screenings for variations in the number of copies of certain genes, as identified by the study.
In the long term, this new biological understanding could help develop treatments and further classifications for neurodevelopmental disorders.