Pubdate: Tue, 24 Mar 2015 Source: Washington Post (DC) Copyright: 2015 The Washington Post Company Contact: http://www.washingtonpost.com/ Details: http://www.mapinc.org/media/491 Author: Linda Searing Quick Study Pot and the Brain DOES MARIJUANA USE IN TEEN YEARS CAUSE MEMORY PROBLEMS IN ADULTHOOD? THE QUESTION When a person smokes marijuana, the chemical THC goes quickly to the brain, producing a mood alteration. How might this affect memory? THIS STUDY analyzed data on 54 people in their mid-20s. Some had smoked marijuana almost daily for about three years when they were teens but had not smoked it for about two years. The other participants had no history of heavy drug use. All were given brain scans and a battery of standardized memory tests to assess their ability to recall information. Among those who had smoked marijuana almost daily, the scans showed an abnormally shaped hippocampus, the part of the brain that is key to longterm memory. The longer they had smoked marijuana, the more abnormal the brain shape. On the memory tests, people who had once been heavy marijuana smokers scored about 18 percent worse than those who had never smoked marijuana regularly. WHO MAY BE AFFECTED? Teenagers who smoke marijuana now and adults who smoked marijuana heavily in their teen years. The National Institute on Drug Abuse notes that marijuana affects brain development, which can be problematic for teenagers because their brains are still developing. CAVEATS The study included a small number of participants. Data on marijuana use came from the participants' responses to interview questions. The study did not determine whether the observed effects were permanent or would change over time. It is possible that the change in brain shape and memory issues occurred before the marijuana use. FIND THIS STUDY March 11 online issue of Hippocampus, viewable at onlinelibrary.wiley.com/doi/10.1002/hipo.22427/ abstract. LEARN MORE ABOUT marijuana and memory at www. drugabuse.gov (search for "marijuana"). Learn about the brain at www. strokeassociation.org (search for "brain tour"). The research described in Quick Study comes from credible, peerreviewed journals. Nonetheless, conclusive evidence about a treatment's effectiveness is rarely found in a single study. Anyone considering changing or beginning treatment of any kind should consult with a physician. - --- MAP posted-by: Jay Bergstrom