health 52

Childhood ADHD and subsequent smoking in adulthood frequently go hand in hand, say the authors, with people who have been diagnosed with ADHD more likely to start smoking early and to smoke twice as much as those without the condition. The researchers focused on five variations in DNA sequences (single nucleotide polymorphisms or SNPs) in different genes that are strongly associated with different aspects of smoking behaviour, such as the number of cigarettes smoked every day, and taking up and quitting smoking. They wanted to see if these might also be linked to hyperactivity in 454 children aged between 6 and 12 with confirmed ADHD and referred to specialist treatment centres. They quizzed the children's mothers about their smoking habits during pregnancy. Of those 394 mothers for whom they had information, 171 had smoked during pregnancy and 223 had not. And they assessed the extent of the children's behavioural and emotional problems at home and at school, as we...

The new research results have been published in the  Journal of Neurophysiology. In Denmark approximately 2-3 per cent of school-age children satisfy diagnostic criteria for ADHD , and therefore it is crucial to know how the medicine works. With a new mathematical reconstruction of a tiny part of the brain region that registers reward and punishment, scientists from the University of Copenhagen are acquiring new knowledge about the effect of ADHD medicine. When reward and punishment signals run through the brain, the chemical dopamine is always involved. "It has been discussed for years whether treating ADHD with Ritalin and similar drugs affects the reward system to any significant degree, simply because the dosage given to patients is so low. We are the first to show that some components of the dopamine signalling pathways are extremely sensitive to drugs like Ritalin. We have also developed a unified theory to describe the effect of such drugs on the dopamine signal,...

While previous research has shown that people with ADHD are more likely to enter a life of crime, it has remained uncertain how ADHD medication affects this risk. After having studied over 25,000 individuals with ADHD from different registries over a four-year period (2006-2009), researchers at Karolinska Institutet have now been able to examine the link between ADHD medication and criminality. The study demonstrates in a variety of ways links between ADHD medication and a reduced risk of criminality. For example, the incidence of criminal behaviour was lower amongst medicated individuals than unmedicated ones; and in the same individual comparing periods of medication with no medication, they also found that ADHD drugs were associated with a significant risk reduction of 32 per cent. This way of studying the same individual is a particular strength in that it shows that the risk reduction is probably not attributable to differences between participants on medication and those not...