Marijuana and Brain Development

Study says smoking marijuana may have long-lasting effects on brain development.
USA Today (11/20, Marcus) reported, "Teenagers respond differently to drugs than adults, and early use may lead to long-lasting effects on brain development, according to new research." Staci Gruber, of Harvard Medical School, presented the study "at the Society for Neuroscience meeting, in San Diego last week," noting "people who start using marijuana at a young age have more cognitive shortfalls." Gruber "evaluated 29 non-smokers and 35 chronic marijuana smokers," and said she found that "while the smokers performed tasks quickly, they did not learn from their errors when corrected -- a hallmark that the part of the brain that governs executive function is impaired." Notably, "functional magnetic resonance imaging (fMRI) backed that up." Data from the National Institute on Drug Abuse show that "marijuana is the most commonly used illegal drug in the US with 25.8 million Americans ages 12 and older reporting at least one instance of abuse in 2008."