Study finds vaping is linked to smoking cigarettes, using marijuana and other drugs over time

U.S. teens and young adults who vape are much more likely to start smoking cigarettes or to begin using cannabis or other drugs, a University of Michigan study, appearing in the journal Drug and Alcohol Dependence, found.

Most vaping studies focus on adolescents (12–17) in short time windows of around two years. Less is known about vaping in young adults (18–25) or the risk of starting other substances like cigarettes, marijuana or other drugs. To that end, researchers examined data from 12-to-25-year-olds over an eight-year period. They found that those who vaped were more likely to start smoking cigarettes, using marijuana or to start other drugs during the study period.

"We found that this risk was persistent over time and was a risk for both adolescents and young adults," said study author Rebecca Evans-Polce, research assistant professor at the U-M School of Nursing. "The risk for starting to use cannabis was the same regardless of whether someone was using e-cigarettes or was using other tobacco products."

Findings for 12-to-17-year-olds over the study period:

• Those who vaped and used other tobacco were 54 times likelier to start smoking, eight times likelier to start using marijuana and three times likelier to start using other drugs.
• Those who vaped only were 22 times likelier to start smoking, seven times likelier to start using marijuana and three times likelier to start using other drugs.

For 18-to-25-year-olds over the study period:

• Those who vaped and used other tobacco were 22 times likelier to start smoking, nine times likelier to start using marijuana and three times likelier to start using other drugs.
• Those who vaped only were 11 times likelier to start smoking, six times likelier to start using marijuana and twice as likely to start using other drugs.

The high risk for both age groups to start smoking after vaping or using other tobacco products was startling, Evans-Polce said.

"The really high odds of cigarette initiation regardless of what type of nicotine or tobacco products you're using is important," she said. "I think it really highlights that to the extent that you can prevent initiation of vaping and other tobacco products, too, you'll also go really far in preventing cigarette initiation over the long term."

Some 39% of teens report vaping by 12th grade and 14% of young adults report vaping in the past month, according to the Substance Abuse and Mental Health Services Administration.

Other data indicate that people are starting cigarette smoking later in life. Historically, people start smoking before they hit their 20s. So, finding that vaping puts young adults at greater risk for cigarette smoking is important when thinking about ways to prevent people from starting cigarette smoking, Evans-Polce said.

The findings also showed the link between nicotine or tobacco use and starting marijuana use increased over time. While marijuana use became more common among adolescents and young adults over the eight years of the study, the risk seemed to increase most dramatically for those who were vaping and using other tobacco products.

Overall, the findings point to a need to develop strategies that prevent young adults from starting to vape, and not focus solely on adolescents, Evans-Polce said. Prevention of vaping may also lead to fewer adolescents and young adults starting cigarettes, marijuana and other drugs.