Smoking, drinking and drug use by American teens are all at all-time lows.
Authors of the annual Monitoring the Future survey believe the overall decline in smoking tobacco led to reduced use of other drugs.
Only 1.8 percent of high school seniors said they smoked at least half a pack of cigarettes a day, compared to 11 percent in 1981. E-cigarettes also slipped a bit, from 16 percent to 12 percent. Researchers have long considered tobacco to be a "gateway drug" for other illicit habits.