Cannabis or marijuana is the illegal drug most commonly used by youth, according to background information in the article. Cannabis use is associated with the use of other substances, including tobacco and illegal drugs. "The gateway theory hypothesizes that the use of legal drugs (tobacco and alcohol) is the previous step to cannabis consumption," the authors write. "However, recent research also indicates that cannabis use may precede or be simultaneous to tobacco use and that, in fact, its use may reinforce cigarette smoking or lead to nicotine addiction independently of smoking status."

J. C. Suris, M.D., Ph.D., and colleagues at the University of Lausanne, Switzerland, analyzed data from a 2002 national survey of Swiss students aged 16 to 20 years. A total of 5,263 students were included in the analysis, including 455 who smoked marijuana only, 1,703 who smoked marijuana and tobacco and 3,105 who abstained from both substances.

"Our findings in this nationally representative sample of adolescents show that 6 percent of them use cannabis without having used tobacco and that one-fifth of current cannabis users (21.1 percent) declare never having used tobacco," the authors write.

The survey also found that, compared with students who used both substances, students who smoked marijuana only were more likely to be male (71.6 percent vs. 59.7 percent), play sports (85.5 percent vs. 66.7 percent), live with both parents (78.2 vs. 68.3) and have good grades (77.5 vs. 66.6). However, they were less likely to have been drunk in the past 30 days (40.5 percent vs. 55 percent), have started using cannabis before the age of 15 years (25.9 percent vs. 37.5 percent), to have smoked marijuana more than once or twice during the previous 30 days (44 percent vs. 66 percent) or to use other illegal drugs (8.4 percent vs. 17.9 percent).

Compared with students who abstained from both substances, marijuana users were more likely to be male (71.6 percent vs. 47.7 percent), to have a good relationship with their friends (87.0 percent vs. 83.2 percent), to be sensation-seeking (37.8 percent vs. 21.8 percent) and to play sports (85.5 percent vs. 76.6 percent), and less likely to have a good relationship with their parents (74.1 percent vs. 82.4 percent).

Although teens who smoke both marijuana and tobacco seem to have more psychosocial problems and thus may be worthy targets for preventive intervention, those who smoke marijuana only also should be monitored closely and counseled. "In any case, and even though they do not seem to have great personal, family, or academic problems, the situation of those adolescents who use cannabis but who declare not using tobacco should not be trivialized," the authors conclude.

Journal reference: Arch Pediatr Adolesc Med. 2007;161(11):1042-1047.

This study was supported by a contract from the Swiss Federal Office of Public Health and the participating cantons. 

Note: If no author is given, the source is cited instead.

• Controlled Substances
• Smoking
• Teen Health

• Marijuana
• Illegal Drugs
• Smoking Addiction

• Cannabis
• Tobacco smoking
• Drug addiction
• Forensic toxicology
• Narcotic
• Analgesic