By Robert Preidt
Columbia University researchers who analyzed national survey data say the "gateway pattern" of substance use is changing. Since 2006, less than 50 percent of teens have tried cigarettes or alcohol before trying marijuana for the first time, the investigators found.
"Alcohol and cigarette use have precipitously declined in adolescent populations for 20 years, while marijuana use has not," said Katherine Keyes, associate professor of epidemiology at Columbia's School of Public Health, in New York City.
"The perceived risk of marijuana use to health among adolescents is declining as well, portending potential future increases. In short, the timing of substances in the 'gateway' sequence is changing, as public perceptions about drugs of abuse change," she added in a university news release.
For the study, the researchers analyzed results of 40 annual national surveys of 12th-grade students.
Among teens who said they'd tried both cigarettes and marijuana, the proportion who tried cigarettes before marijuana fell from 75 percent in 1995 to 40 percent in 2016.
The proportion who tried cigarettes in the same school grade as marijuana rose from 20 percent in 1994 to 32 percent in 2016.
Among students who said they'd tried both alcohol and marijuana, the proportion who tried alcohol before marijuana fell from 69 percent in 1995 to 47 percent in 1999.
"Reducing adolescent smoking has been a remarkable achievement of the past 20 years," Keyes noted.
"Now, the more prominent role of marijuana in the early stages of drug use sequences and its implications are important to continue tracking. Its increasing use suggests that marijuana is, and will continue to be, a key target of drug use prevention efforts," she concluded.
The study was published online recently in the journal Drug and Alcohol Dependence.