Pubdate: Thu, 24 Apr 2014 Source: USA Today (US) Copyright: 2014 USA TODAY, a division of Gannett Co. Inc Contact: http://mapinc.org/url/625HdBMl Website: http://www.usatoday.com/printedition/news/index.htm Details: http://www.mapinc.org/media/466 Author: Alisa A. Padon Page: 9A POT'S EFFECT ON THE BRAIN A recent study on differences in brain structures and marijuana use is getting a lot of attention for all the wrong reasons ("Casual pot use messes with brain?" News, April 16). Coverage of the story has heralded that casual marijuana use can cause brain abnormalities, which is very misleading. The researchers looked at brain differences between casual marijuana users and non-users at one point in time and saw a correlation. That is, the users' brains were different from non-users'. This kind of research says nothing about what caused the differences. To do that, you need to look for brain changes following drug use over time, and even then it may be that these abnormalities incline individuals to smoke, or that someone inclined to smoke is also inclined to do other things that cause changes. It's up to researchers to be very clear about what they did or did not prove. In this case, deliberately or not, the limits of their conclusions were lost in a cloud of smoke. Alisa A. Padon Baltimore - --- MAP posted-by: Jay Bergstrom