Pubdate: Wed, 16 Apr 2014 Source: Times-Tribune, The (Scranton PA) Copyright: 2014 Associated Press Contact: http://www.thetimes-tribune.com Details: http://www.mapinc.org/media/4440 Author: Malcolm Ritter, Associated Press POT SHOWS BRAIN EFFECTS Long-Term Casual Smokers May Have Changes NEW YORK (AP) - A small study of casual marijuana smokers has turned up evidence of changes in the brain, a possible sign of trouble ahead, researchers say he young adults who volunteered for the study were not dependent on pot, nor did they show any marijuana-related problems. "What we think we are seeing here is a very early indication of what becomes a problem later on with prolonged use" - things like lack of focus and impaired judgment, said Dr. Hans Breiter, a study author. Longer-term studies will be needed to see if such brain changes cause any symptoms over time, said Dr. Breiter, of the Northwestern University Feinberg School of Medicine and Massachusetts General Hospital. Previous studies have shown mixed results in looking for brain changes from marijuana use, perhaps because of differences in the techniques used, he and others noted in today's issue of the Journal of Neurosciences. The study is among the first to focus on possible brain effects in recreational pot smokers, said Dr. Nora Volkow, director of the National Institute on Drug Abuse. The federal agency helped pay for the work. She called the work important but preliminary. Dr. Volkow said larger studies are needed to explore whether casual to moderate marijuana use really does cause anatomical brain changes, and if so, whether that leads to impairment. Murat Yucel of Monash University in Australia, who has studied the brains of marijuana users but didn't participate in the new study, said in an email that the new results suggest "the effects of marijuana can occur much earlier than previously thought." Some of the effect may depend on a person's age when marijuana use starts, he said. ONLINE: www.jneurosci.org - --- MAP posted-by: Jay Bergstrom