Teen Cannabis Use Tied to Harmful Substance Use Later

By Amy Orciari Herman

Edited by Susan Sadoughi, MD

Teens who use cannabis even occasionally are more likely to misuse other drugs and alcohol in early adulthood, according to a study in the Journal of Epidemiology and Community Health.

Over 5300 U.K. adolescents answered questions on cannabis use several times between ages 13 and 18 and then were followed up at age 21. Roughly 80% were cannabis nonusers as teens, 17% were occasional users, and 3% were regular users (at least once weekly).

After adjustment for demographics, conduct problems, and early alcohol and tobacco use, cannabis use in adolescence was associated with harmful substance use later. Substance use rates at age 21 according to teen cannabis use were as follows:

• Nicotine dependence:1% of cannabis nonusers versus roughly 5% of occasional users and 21% of regular users

• Harmful alcohol consumption: 8% of cannabis nonusers versus 28%–43% of occasional users and 24% of regular users

• Other illicit drug use:14% of cannabis nonusers versus 83% of occasional users and 94% of regular users