What Causes ADHD in Children Born Small?

Background to research

Attention Deficit Hyperactive Disorder (ADHD) is the most prevalent childhood neurodevelopmental disorder of childhood and is commonly associated in children with poor pre-academic skills, language problems, social difficulties and academic failure. Many children with ADHD continue to experience social and learning difficulties into late adolescence with symptoms often persisting into adulthood. ADHD may also be accompanied by symptoms of many psychiatric and other medical conditions.

There are many environmental factors proven to be connected to the development of ADHD e.g. maternal smoking during pregnancy, sleep problems and being born on time but with a low birth weight (also known as small for gestational age - or SGA). A number of genes have also been identified that are associated with the disorder. It is highly likely that ADHD might originate in genes, but the development of the disorder is influenced by the way these genes interact with and affect a person’s response to environmental factors. One method of researching this is by examining gene - environment interactions or GxE.

What are your research objectives?
The main aim of this project is to examine the effects of prenatal environmental adversity and genetic risk on ADHD. We want to see how children who are born SGA, differ from those who were born appropriate for their gestational age. The results of this study will improve our understanding of ADHD, in particular in children who are born SGA. It will also contribute to a growing amount of research into the genetic determinants of the disorder.

How you will conduct your research?
This research will be conducted using data collected by the Auckland Birthweight Collaborative (ABC) Study. This study has collected information from a large group of Auckland children over the past 12 years; half of this group of children was born small and the remaining were normal size. A wide range of developmental, medical and socio-demographic information has been gathered starting at the time of the child’s birth then at ages 1, 3, 7 and 11 years.

Are there others in your field, in New Zealand or globally, conducting similar research?
Many studies both within New Zealand and internationally have researched factors that are associated with the development of ADHD. In the past decade there has also been an increasing amount of research into the genetics of ADHD. To the best of our knowledge no other research (within NZ or internationally) has been published on the effects of prenatal environment adversity and genetic risk on ADHD relating to children bon SGA.

What is innovative about the approach you are taking?
Few longitudinal studies exist that have collected a wide range of objective information from birth through to early adolescence. This project is also important as it will contribute to the growing research into the genetics of ADHD in a unique sample of SGA children.

If you are successful with your objectives what will that mean to those suffering from the disease or to the knowledge advancement of this disease?
The outcome of this research will facilitate public health policies targeted at prevention and identification of ADHD and its associated comorbidities. It will also add to the growing body of research on the genetics of ADHD, in particular the novel approach of examining gene-environment interactions.

Is there is an international or national collaboration on your project?
This project is an international collaboration between the Auckland Birthweight Collaborative (ABC) Study, University of Auckland, NZ and the Institute for Disorders of Impulse and Attention (IDIA), University of Southampton, UK.

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