Teen marijuana use up, while some drugs decline
Marijuana use among American adolescents has increased gradually over the past two years (three years among 12th-graders) following years of declining use, according to the latest Monitoring the Future study, which has tracked drug use among U.S. teens since 1975.
"So far, we have not seen any dramatic rise in marijuana use, but the upward trending of the past two or three years stands in stark contrast to the steady decline that preceded it for nearly a decade," says researcher Lloyd Johnston, the study's principal investigator.
"Not only is use rising, but a key belief about the degree of risk associated with marijuana use has been in decline among young people even longer, and the degree to which teens disapprove of use of the drug has recently begun to decline. Changes in these beliefs and attitudes are often very influential in driving changes in use."
The proportion of young people using any illicit drug also slightly is up over the past two years. This measure is driven largely by marijuana use, because marijuana is the most widely used of all illicit drugs. In 2009 marijuana use in the prior 12 months (the annual prevalence rate) was reported by about 12 percent of the nation's eighth-graders, 27 percent of 10th-graders and a third of 12th-graders. The proportions saying they used any illicit drug in the past year are 15 percent, 29 percent and 37 percent, respectively.
The proportion of students reporting using any illicit drug other than marijuana has continued to decline for students in the eighth and 12th grades in 2009. The prevalence rates for using any such drug in the prior 12 months are 7 percent, 12 percent and 17 percent in grades eight, 10 and 12, respectively.
There were declines this year in the use of several specific drug classes. High school seniors showed significant drops in their use of LSD and other hallucinogens, continuing long-term gradual declines (use of these drugs had shown previous declines in the lower grades). There was some continuing decline in all grades in the use of cocaine specifically, powder cocaine with annual usage levels reaching the lowest levels since the early 1990s.
While use of ecstasy, inhalants and LSD is not rising currently, the investigators remain concerned because the perceived risk associated with those drugs has been dropping for several years and may leave young people open to renewed interest in those drugs.
The proportion of young people who see "great risk" associated with trying ecstasy has fallen appreciably and steadily since 2004 (2005, in the case of 12th-graders).
"Given the glamorous name and reputation of this drug, I could easily imagine it making a comeback as younger children entering their teens become increasingly unaware of its risks," Johnston says. "And, while LSD use is at historically low levels at present, the proportion of students seeing its use as dangerous has been in decline for a long time (although it did not decline further this year in two of the three grades), removing a major obstacle to experimentation. We have seen LSD make a comeback before. Clearly, it could happen again."
Likewise, eighth- and 10th-graders, who are most likely to inhale or "huff" gases and aerosols to get high, have shown a steady decline since 2001 in the belief that experimenting with inhalants is dangerous.
"This leaves them more vulnerable to any new stimulus toward trying inhalants," Johnston says.
Alcohol use generally has been in a long-term, gradual decline at all three grade levels, with 30-day (or past month) prevalence having fallen from recent peak levels by more than 40 percent among eighth-graders, by more than 25 percent among 10th-graders, and by about one-sixth among 12th-graders. For this year only, eighth-graders showed a continuation of the decline, while use in the upper grades leveled off.