According to a study published in the July issue of the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP), teens commonly use other people’s medical marijuana.

For the study, conducted in Denver, 121 of 164 teens said they had used medical marijuana that was not meant for them. These teens had used the diverted marijuana a median of 50 times.

“Many high-risk adolescent patients in substance abuse treatment have used diverted medical marijuana on multiple occasions, which implies that substantial diversion is occurring from registered users,” said lead author Stacy Salomonsen-Sautel, Ph.D., senior professional research assistant with the Department of Psychiatry at the University of Colorado. “Our results support the need for policy changes that protect against diversion of medical marijuana to adolescents."

In a related editorial, Alessandra N. Kazura, M.D. of the Maine Medical Center Department of Psychiatry in Portland, questioned whether marijuana was effective and safe as a medicine, and also discussed the message it gives about risks to adolescents.

Colorado has had widespread legalized medical marijuana, but at the time the study was done, only 41 adolescents in the state had registry identification cards for medical marijuana. This suggests that the teens are more likely to get medical marijuana rom adults than peers.

The study was funded by the National Institute on Drug Abuse, with additional funding from the National Institute on Alcohol Abuse and Alcoholism.