With marijuana now legal in my home state of California, more and more teens are under the impression that using the substance is "no big deal". In the short term, marijuana can impair judgement, coordination and memory. Regular use in teen years can have long term consequences on memory, learning, and IQ, and there is an association between heavy teen use and both mood disorders and schizophrenia later in life. Because of their adolescent brain development, teens are more likely to become addicted to ANY substance than adults. Here's my interview on the subject with SmartSocial.com.