Brain networks and teenage drug use
Scientists have discovered a number brain networks connected to teenage drug use and ADHD. The findings, published in Nature Neuroscience, are based on data collected by IMAGEN, a large European research project led by Professor Gunter Schumann at King’s College London’s Institute of Psychiatry.
The researchers gathered behavioural, genetic and fMRI imaging data from 1,896 14-year-olds across Europe. Researchers also measured participants’ "stop-signal reaction time”. The teenagers were asked to perform a repetitive task that involved pushing a button on a keyboard, but then being able to successfully stop—or inhibit—pushing the button in mid-action, a standard measure of overall inhibitory control. Those with better inhibitory control, and therefore less impulsive were able to succeed at this task faster.
The data was analysed by research teams from around the world, including the University of Vermont. The researchers found that diminished activity in a network of the brain involving the orbito-frontal cortex was associated higher impulsivity and with experimentation with alcohol, cigarettes and illegal drugs in early adolescence. The researchers also found a number of different networks associated with symptoms of attention-deficit hyperactivity disorder (ADHD).
Professor Schumann, Chair of Biological Psychiatry at the IoP at King’s says: ‘We have known for a long time, that both ADHD and drug abuse are problems that plague impulsive people, suggesting a possible connection between both disorders. I think the most striking finding is that ADHD and early drug use are not linked to the same brain networks. Impulsivity can be broken down into different brain regions – it might be that one region is linked to ADHD and another to drug use.’
Professor Schumann adds: ‘In the UK, as in most developed countries, most incidents of serious harm caused to teenagers are because of preventable or self-inflicted accidents often as a result of them partaking in impulsive, risky behaviour often associated with alcohol or drug use. Understanding why some teenagers at a higher risk than others of partaking in this type of behaviour could have large implications for public health.’
The impulsivity networks identified by the researchers begin to paint a more nuanced portrait of the neurobiology underlying the attributes and behaviours associated with impulsivity.
The IMAGEN Consortium is funded by the European Union. The consortium brings together scientists across Europe to carry out neuroimaging, genetic and behavioral analyses in 2,000 teenage volunteers in Ireland, England, France, and Germany. The team will be following them for several years, investigating the roots of risk-taking behaviour and mental health in teenagers.
For full paper: Whelan, R. et al. ‘Adolescent impulsivity phenotypes characterized by distinct brain networks’ Nature Neuroscience 2012 doi: 10.1038/nn.3092
For further information, please contact Seil Collins, Press Officer, Institute of Psychiatry email: seil.collins@kcl.ac.uk or tel: 0207 848 5377