Pubdate: Sun, 19 Jun 2005 Source: Province, The (CN BC) Copyright: 2005 The Province Contact: http://www.canada.com/vancouver/theprovince/ Details: http://www.mapinc.org/media/476 Author: Daily Telegraph (UK) Bookmark: http://www.mapinc.org/pot.htm (Cannabis) Bookmark: http://www.mapinc.org/youth.htm (Youth) POT MESSES WITH TEEN'S BRAIN: STUDY LONDON -- Young people who occasionally smoke cannabis over long periods are more likely to turn to more addictive drugs like heroin, suggests a new study. While it has been assumed that the brain is almost fully formed by the time children reach their teens, there is evidence that the brain continues to develop until 25. Experiments on rats by Yasmin Hurd, a professor at the Karolinska Institute in Sweden, show that chronic, periodic use of cannabis can interfere with brain development. If confirmed, the findings suggest that children and young adults who use the drug over long periods would be more prone to anxiety and more dependent on anxiety-reducing drugs. "The developing brain is definitely more sensitive,'' Hurd says. "Many people think that all cannabis does is to give you a calm, relaxed feeling and no long-term effects. "Cannabis may be less addictive than, for example, cocaine or heroin, but it is still a drug.'' Robin Murray, a professor at London's Institute of Psychiatry, agreed. "Clearly it needs to be replicated, but there is already evidence that, in animals, cannabis and amphetamine show cross-tolerance. "So that rodents given THC, the active ingredient of cannabis, show greater effects when given amphetamine. "This suggests that it may be easier to come to grief when you try heavy drugs if you have already sensitized your brain receptors with cannabis. We need more basic and clinical research into the long-term effects.'' What do you think? Give us your comments by fax at 604-605-2223, or by e-mail --- MAP posted-by: Larry Seguin