Whether teen marijuana users end up quitting the drug depends largely on who their friends are, a new study suggests.
The study involved 458 high school students in the United States who said they had smoked marijuana at least four times in the past month.
After a year, 19 percent of participants had stopped using marijuana.
Teens were less likely to quit if they had friends who also smoked marijuana, or if none of their friends attended their school. Teens were more likely to quit if their friends did not use marijuana, the researchers said.
A slew of other personal and family factors — such as whether participants lived in a safe or disadvantaged neighborhood or had controlling parents — held little influence over teens' likelihood of quitting, said study researcher Michael S. Pollard, a sociologist at the RAND Corporation, a nonprofit research organization.
Marijuana users tend to make friends with other people who already smoke marijuana, studies show. These friends don't induce teens to use the drug per se, but they don't help them quit, either, said Pollard, who presented his work here this week at the American Sociological Association meeting. "This is a behavior that's much harder to stop when you're surrounded by people who engage in the same behavior," he said.