Ealing-based doctor researched influence of brain chemical dopamine
An Ealing-based psychiatrist has won the prestigious Royal Society of Medicine prize for the most outstanding original research work in mental health during the past year.
The groundbreaking research by Dr Paul Stokes and his team investigated whether nature or nurture has the greater influence on the production of a chemical often linked to serious mental health disorders ranging from schizophrenia to addictive behaviour.
Their study focused on the production of the brain chemical dopamine and concluded that dopamine function is more influenced by environmental factors specific to an individual than by genetic inheritance.
Their findings could lead to changes in the medical approach to the treatment of mental illness.
Dr. Stokes said: “This supports evidence in the research literature that preventing drug misuse and cannabis use and addressing other environmental factors in adolescence and early adulthood could potentially have an impact on reducing serious mental illness.”
His paper, ‘Nature or Nurture? Determining the Heritability of Human Striatal Dopamine Function’ won in the psychiatry section for mental health research. Dr. Stokes is an academic consultant psychiatrist at West London Mental Health NHS Trust and Imperial College,
Dopamine transmits nerve signals and its function in the part of the brain known as the striatum is important in signalling reward, integrating information from other parts of the brain, and in movement. Critically, it is involved in a number of mental health disorders, including schizophrenia, attention deficit hyperactivity disorder (ADHD) and addiction.
Dr Stokes used positron emission tomography (PET) brain imaging to measure dopamine function in healthy identical and non-identical twins. This research was funded by the Medical Research Council, UK.
The research measured the variability in uptake values in 9 pairs of identical twins and 10 pairs of non-identical twins and found that dopamine function is more influenced by environmental factors specific to an individual than by genetic inheritance. They also found that environmental factors shared between family members had no influence on dopamine function in the striatum.
Dr Stokes said: “My study indicates that changes in dopamine function in the striatum, which may underlie important mental health problems such as schizophrenia and addictions, are more likely to be related to environmental influences that a person may experience in late childhood or early adulthood rather than inherited genetic risk factors for these conditions.
“This supports evidence in the research literature that preventing drug misuse and cannabis use and addressing other environmental factors in adolescence and early adulthood could potentially have an impact on reducing serious mental illness.”
The research found the greatest influence of genetics in an area of the striatum which regulates habit formation and that the effect of individual environmental factors was greatest in an area of the striatum which is involved in emotions, especially in reward and pleasure.
‘Nature or Nurture? Determining the Heritability of Human Striatal Dopamine Function: an {18F}-DOPA PET Study’ was published in the highly respected journal Neuropsychopharmacology in October 2012. Neuropsychopharmacology. 2013 Feb ;38(3):485-91. doi: 10.1038/npp.2012.207. Epub 2012 Oct 24.
Dr Paul Stokes MB ChB BSc (Hons) MRCPsych DIC PhD, divides his work between research and clinical practice. His clinical work is with Ealing East recovery team, where he spends two days a week.
May 16, 2013