Proponents of marijuana use tout its harmlessness, claiming that it’s not addictive and totally innocuous. However, the truth is that around 9% of marijuana users become addicted, and heavy use from a young age can have permanent detrimental effects on brain function. Adolescents who begin smoking marijuana frequently have a risk of becoming addicted, doing poorly in school, and needing treatment in drug rehab.   Marijuana is one of the most used drugs by adolescents and college aged young adults. In 2014, daily marijuana use was at 5.9% among college students. Among younger kids, 6% of high school seniors smoke pot daily, and 21.2% reported last-month use of marijuana. However, only 36.1% of 12th graders believe that regular marijuana use puts the user at great risk. This is a problem, as research has shown that heavy marijuana use from a young age can irrevocably damage brains and hamper academic success, sometimes necessitating treatment in an addiction treatment facility.   The most obvious detrimental effect of regular marijuana use is that it causes students to miss class in order to get high. As students miss out on classes, they fall behind on material, become discouraged, and stop doing homework. They perform poorly on tests and projects, and their GPA suffers as a result.   Unfortunately, heavy marijuana use also affects young adults in less visible ways. A study has found that marijuana impairs the function of working memory. We use working…