The number of 12 to 21-year olds who used marijuana before any other drug (including cigarettes and alcohol) nearly doubled from 4.8% in 2004 to 8% in 2014, Newsweek reports about the National Institute of Child Health and Human Development study. Over the same period, the number of smokers in that age group has significantly declined from 21% to only 9%.

More young people are also opting to abstain from drug use entirely. Thirty-six percent of respondents said they didn’t use drugs at all in 2004 versus 46% abstaining in 2014.

In the study, the National Institute of Child Health and Human Development surveyed 275,000 teens and young adults about their use of alcohol, cigarettes, marijuana, and illegal drugs. The study’s results were published in the journal Prevention Science.

The study also claims that young people who start using marijuana before they use other drugs are more likely to become heavy users and have cannabis-related HEALTH????? problems in the future. The study’s authors suggested that drug prevention strategies should be targeted at high-risk groups, notably American Indian/Alaska Native and black youth.