Miller said he first used cannabis at 12 years old. The University of Minnesota study looked at data from the Minnesota Student Survey given every three years. In addition to less cannabis use overall, researchers saw less disparities in cannabis use between kids from non-marginalized and groups and kids from marginalized groups. Dr. Eisenberg isn’t exactly sure why cannabis use is down for Minnesota teens. Minnesota middle schools and high schools are required to start teaching students about cannabis and its effects this upcoming school year.