Professor Anita Thapar CBE (PhD 1995) is a researcher focusing on the genetic and environmental causes of Attention Deficit Hyperactivity Disorder (ADHD) and youth depression.
Can you briefly explain what is meant by ADHD?
ADHD is a disabling and often misunderstood brain disorder. Its symptoms include severe inattentiveness, hyperactivity and impulsiveness. These symptoms typically onset at an early age, but may become more apparent when intellectual and social demands increase – for example at school. It is estimated between 1.4 and 3% of the population are affected. Children with ADHD often have other neurodevelopmental difficulties such as language, learning and autistic problems. ADHD can have lifelong consequences; those affected can continue to have ADHD in adult life, as well as developing new mental health and social difficulties such as depression.
What drew you to researching in this area?
I’ve always been passionate about child and adolescent psychiatry. I became interested in ADHD genetics while training as a child and adolescent psychiatrist within the NHS; I saw a family where 5 children all had ADHD.
I believe that, in the field of child psychiatry, it is vitally important to generate high quality scientific evidence to inform practice and dispel stigma.
In 1999, you were made Wales’ first Professor in Child and Adolescent Psychiatry. Can you summarise developments in the field since then?
When I became a professor, genetic research into child psychiatry lagged behind other medical disorders. The significance of the genetic contribution was often misunderstood – either ignored or, seen in simplistic terms: disorders were the result of either genes or environment. Psychiatric disorders, like most common medical disorders, are a combination of both.
In the past parents were blamed for many child mental health problems including autism.
However, we and others have found that ADHD runs in families; twin studies consistently show very high heritability.
We then turned to molecular genetic investigations. We found an increased burden of rare chromosomal deletions and duplications in ADHD and showed that there is an important overlap with other neurodevelopmental problems, notably, autism spectrum disorder and schizophrenia.
Finding environmental factors has been more difficult. I have been especially interested in environmental exposures whilst the baby is in the womb.
In one research project, we studied children born by IVF to assess the impact of both genetic and prenatal risk factors on ADHD. We were particularly interested in children who were genetically unrelated to the pregnant woman. If a prenatal exposure has a genuine causal effect on the baby it won’t matter if the mother is genetically related.
To our surprise, although we found that maternal smoking had a causal effect in lowering birth weight, it did not cause ADHD.
Research has helped change the conversation around ADHD and shifted blame which was often placed on parents. A lot of work remains, but it is encouraging that we have such as a talented generation of new researchers, clinicians and students here in Cardiff who want to push the field forward.