Pubdate: Mon, 03 Dec 2001 Source: Age, The (Australia) Copyright: 2001 The Age Company Ltd Contact: http://www.theage.com.au/ Details: http://www.mapinc.org/media/5 Author: Penny Fannin, Science Reporter STUDY FINDS STIMULANTS CAN HEAD OFF ADDICTION Giving Ritalin or other stimulants to children with attention deficit hyperactivity disorder could reduce their chance of becoming drug addicts in later life. A study has shown that rats given Ritalin during pre-adolescence undergo behavioural and neurological changes that make cocaine unappealing and that this state lasts into adulthood. Some researchers have suggested exposure to stimulants in adulthood increases sensitivity to drugs of abuse, raising the possibility that children treated with Ritalin might be at greater risk of drug abuse later in life. But Susan Andersen and colleagues at Harvard Medical School have provided evidence against this idea by injecting pre-adolescent rats with Ritalin and then examining their sensitivity to cocaine during adulthood. Using place conditioning - a procedure in which rats learn to associate drug effects with particular environments - they found that rats treated with Ritalin as juveniles spent less time in places associated with cocaine use. Rats given Ritalin in adulthood also spent less time in places associated with cocaine than normal animals, but the change was not as great as in the younger group, Dr Andersen said. "(Ritalin) exposure in developing rats seems to decrease responsiveness to cocaine's rewarding effects and increase responsiveness to its aversive effects," she said. The research is published in the current issue of the journal Nature Neuroscience. Daryl Efron, a paediatrician at Melbourne's Royal Children's Hospital, said the research was good news for parents of children who were treated with stimulants for the disorder. "It really supports the clinical and epidemiological data that we have had previously suggesting that children with ADHD who are treated with Ritalin have less chance of substance abuse later in life," he said. - --- MAP posted-by: Josh