Teen substance use shows decline.

• Position: YOUR LIFE

The annual Monitoring the Future survey results from the National Institutes of Health, Bethesda, Md., show a continued long-term decline in the use of many illicit substances, including marijuana, alcohol, and tobacco, as well as the misuse of some prescription medications, among the nation's teens.

The MTF survey measures drug use and attitudes among eighth-, 10th-, and 12th-graders. Findings from the survey indicate that past-year use of any illicit drug was the lowest in the survey's history for eighth-graders, while past-year use of illicit drugs other than marijuana is down from recent peaks in all three grades.

Marijuana use in the past month among eighth-graders dropped to 5.4% in 2016, from 6.5% in 2015. Daily use among eighth-graders dropped in 2016 to 0.7%, from 1.1% in 2015. However, among high school seniors, 22.5% report past-month marijuana use and six percent report daily use; both measures remained relatively stable from 2015. Similarly, rates of marijuana use in the past year among 10th-graders remained stable compared to 2015, but are at their lowest levels in more than two decades.

The survey also shows that there continues to be a higher rate of marijuana use among 12th-graders in states with medical marijuana laws, compared to states without...