With more than 25% of high school seniors reporting recent use and 6.5% of 12th graders being daily users, marijuana (MJ) is the most frequently used illicit substance among adolescents. Across all age groups over 70% of new drug initiates start with using MJ at an average age of 18 years. MJ use in early adolescence is associated with increased risk of greater substance use, … Continue reading Neuroimaging shows that young starting age of marijuana causes arrested neurodevelopment.