Teens are trying marijuana before alcohol and tobacco

Teens used to try alcohol first, then tobacco, and then marijuana. Now, marijuana is increasingly the first “gateway” substance for adolescents, according to new research.This trend is not because teens are smoking cannabis more than ever. Rather, the change is because teens are smoking cigarettes and drinking less while the numbers for marijuana have held steady, according to Katherine M. Keyes, a professor of epidemiology at Columbia University and co-author of the new study, publ