Legalization of marijuana for medical purposes/recreational use coincides with a decrease in perceived harmfulness of the drug and increases adolescent use. 9% of children in grade 9-12 use marijuana daily/almost every day. Marijuana exposure in adolescence is associated with use of other illicit drugs and increased emergency unit visits in the pediatric population. 17% of youth using marijuana develop a cannabis use disorder, recognized in the DSM-V as physical dependence. 68% of youth presenting for treatment report dependence, tolerance and withdrawal. Marijuana intoxication may cause acute psychosis and adolescent exposure predicts a twofold increased risk of developing psychosis and schizophrenia in adulthood. There is also an association between chronic use and suicidal ideation/attempt. Adolescent use causes cognitive impairment and decreases academic performance. Pediatricians must be aware of the problem and incorporate questions about substance abuse and education/intervention in their consultations.
