ANN ARBOR, Mich.—The percentage of U.S. adolescents who use illicit drugs or drink alcohol continued a decade-long drop in 2006, according to the 32nd annual Monitoring the Future survey of 50,000 8th, 10th, and 12th graders in more than 400 schools nationwide.
This year's survey reveals that a fifth (21 percent) of today's 8th graders, over a third (36 percent) of 10th graders, and about half (48 percent) of all 12th graders have ever taken any illicit drug during their lifetime.
The proportion saying they used any illicit drug in the prior 12 months (called " annual prevalence" ) continued to decline in 2006, and the rates (15 percent, 29 percent, and 37 percent in 8th, 10th, and 12th grades, respectively) are now down from recent peak levels in the mid-1990s by about one third in 8th grade, one quarter in 10th grade, and one eighth in 12th grade.
However, the declines since last year are relatively small" only 0.7, 1.0, and 1.9 percentage points, respectively. (The 2005-2006 decline is statistically significant for the three grades combined, but not for any one grade taken individually.)
Marijuana, by far the most widely used of the various illicitly drugs, showed the fifth consecutive year of decrease among 10th- and 12th- grade students. But it appears that the recent declines in marijuana use have stopped among 8th graders, whose annual prevalence rate in 2006 was nearly identical to what it was in 2004.
It is now the older students who are showing the greatest decreases in their use. In 2006 the annual prevalence for marijuana was 12 percent in 8th grade, 25 percent in 10th grade, and 32 percent in 12th grade. These rates reflect declines from a year earlier (2005) of 0.5, 1.4, and 2.1 percentage points, respectively. (Individually, none of these three declines is statistically significant, but for the three grades combined the decline is significant.)
The proportions using any illicit drug other than marijuana showed very little further decline this year (none statistically significant), but the greatest improvement (a half of a percentage point decline) occurred among the 12th graders. (This greater improvement among the older students seems to be happening for a number of drugs.)
The proportions of students who have gone beyond marijuana to using one or more of the other illicit drugs" such as hallucinogens, cocaine, heroin, or non-prescribed stimulants, sedatives, tranquillizers, or other narcotics" were 8 percent, 13 percent, and 19 percent in 2006 in grades 8, 10, and 12.
"The youngest students that we survey "the 8th graders" have shown the largest proportional drop in their use of nearly all of the illicit drugs since the recent peak rates of the mid to late 1990s, said University of Michigan researcher Lloyd Johnston, the principal investigator of the study.
"The 8th graders generally were the first to show the declines; but, their improvements now seem near an end. The older teens, on the other hand, are showing a continuation of their decreases, as they catch up with the progress of the younger age groups. We believe that this reflects what social scientists call a 'cohort effect,' in which class cohorts of 8th graders, in this case, are bringing their lower levels of drug use with them as they age and replace previous cohorts of 10th and 12th graders."
The findings based on the 2006 survey results will be published in a forthcoming report. In addition to Johnston, the study team and authors of that report are Patrick O'Malley, Jerald Bachman, and John Schulenberg" all are research professors at the U-M Institute for Social Research and either social or developmental psychologists.
Methamphetamine use declined significantly among 10th graders this year, but not in the two other grades. In general, methamphetamine use has been declining in these populations since it was first added to the study in 1999, with the cumulative proportional declines now ranging from four tenths to six tenths across the three grades. The annual prevalence rates for methamphetamine are now 1.8 percent, 1.8 percent, and 2.5 percent in grades 8, 10, and 12.
Crack cocaine use has been in gradual decline in all three grades since the recent peak levels reached in the late 1990s, with proportional declines since then of about 40 percent, 50 percent, and 20 percent in grades 8, 10, and 12, respectively. Annual prevalence in 2006 is only 1.3 percent, 1.3 percent, and 2.1 percent in the three grades, respectively. This year only the 10th graders showed further decline (down 0.4 percentage points from 1.7 percent to 1.3 percent, which was a statistically significant decline).
Drugs showing no change in use this year
Many drugs showed no or very little further decline in 2006 at any grade, including inhalants, LSD, hallucinogens other than LSD, powder cocaine, crystal methamphetamine (" ice" ), heroin, narcotics other than heroin, tranquilizers, sedatives, several " club drugs" (Ketamine, Rohypnol, and GHB), and steroids. Many of these drugs had previously declined by substantial proportions following the period of resurgence in drug use in the 1990s. (See accompanying figures.) Two drugs in particular showed dramatic declines earlier in the decade, namely LSD and ecstasy, with the annual prevalence of each having fallen by more than half since 2001.
The use of inhalants had been rising over the past several years. In 2006, however, 8th and 12th grades showed no further increase; only 10th grade showed a 0.5 percentage point rise (non-significant). But the investigators are still concerned about a continuing decline in "perceived risk" the proportion of students seeing this class of drugs as dangerous has been decreasing steadily in the lower grades for the past five years.
"Perceived risk is often a leading indicator of changes in actual use," Johnston said. "So, when we see a change like this, we take it as an early warning of trouble ahead. We think that there is a growing need to educate these new cohorts of young people about the dangers of inhalant abuse so that a further resurgence in use does not occur."
The use of anabolic steroids has received considerable attention in the media in the past two years, largely because of allegations of widespread use, and congressional hearings on their use, by professional baseball players. While steroid use did rise among teens in the late 1990s, and on into the early 2000s in the case of the older teens, the proportion of 8th and 10th graders reporting using steroids in the prior 12 months has dropped on the order of one half from recent peak levels, while use among 12th graders has declined by over one quarter since 2002.
None of these declines continued this year, however. There was no appreciable change in usage rates in any of the three grades, where about 1 percent, 1 percent, and 2 percent of 8th, 10th, and 12th graders, respectively, reported any steroid use in the prior year. Use remains considerably higher among boys than among girls.
Drugs showing evidence of increasing use this year
There was very little evidence of increasing drug use this year. Ecstasy showed a not-quite-significant 1.1 percentage point increase among 12th graders in their annual prevalence of use, increasing from 3 percent in 2005 to 4.1 percent in 2006; however, there was little change in the proportion of 8th or 10th graders saying that they used ecstasy.
"We have seen a reduction over the past one to three years in the proportions of students saying that they think using ecstasy is dangerous, or that they disapprove of its use," Johnston noted. "Again, this could be setting the stage for a resurgence in the use of this drug, since use often moves with these beliefs and attitudes."
There was also some evidence of increases in the use of OxyContin and Vicodin, both of which will be discussed below along with the other prescription-type controlled substances.
Use of prescription-type drugs remains high
Not all drugs have shown appreciable declines from their recent peaks. In particular, the use of prescription-type drugs like narcotics, tranquilizers, and sedatives remains at relatively high levels.
After a long period of steady increasing use among 12th graders (data for 8th and 10th graders are not available), narcotic drugs other than heroin reached a peak very recently, in 2004. There has been relatively little decline in the use of this class of drugs since then. (The annual prevalence rate reached 9.5 percent among 12th graders in 2004 and stands at 9 percent in 2006.) This general class of drugs contains narcotic pain relievers, two of which are OxyContin and Vicodin (and data for 8th and 10th graders are available for these two specific drugs).
OxyContin use increased steadily among 12th graders from when it was first measured in 2002 until 2005, with annual prevalence rising from 4 percent to 5.5 percent, before dropping back this year to 4.3 percent. Unfortunately, the younger students, who had not previously been showing much increase in their OxyContin use, reached their highest levels observed so far, with an annual prevalence in 8th grade of 2.6 percent and in 10th grade of 3.8 percent in 2006.
"Obviously, relatively few young people are using OxyContin; still, given the addictive potential of this strong narcotic drug, I think we should be concerned about these rates," Johnston said.
Vicodin is another specific narcotic drug used for pain control, which has an even higher prevalence rate than OxyContin. In 2006 it showed an annual prevalence among 8th, 10th, and 12th graders of 3 percent, 7 percent, and 9.7 percent, respectively. These rates all reflect some increase in 2006 over 2005, though none of the increases reaches statistical significance. However, over the longer interval of 2002 (when Vicodin was first measured) to 2006, use actually has remained relatively stable.
Sedatives, including barbiturate sedatives, are another class of prescription-type drugs that showed a substantial, if gradual, increase over a period of years. Use is reported only for 12th graders, among whom annual prevalence rose from 2.8 percent in 1993 to 7.2 percent in 2005. This year use finally leveled, falling a not-statistically-significant 0.6 percentage points to 6.6 percent. This marks the end of a long rise, but the investigators point out that the use of this class of drugs outside of medical regimen is still near its recent peak.
"Because most of the illegal drugs like LSD, ecstasy, cocaine, and heroin have shown considerable declines in recent years, while the misuse of prescription-type drugs has been growing, the latter have become a more important part of the country's drug problem," Johnston concluded. " Marijuana is still by far the most widely used of all of the illicit drugs, but even its use has been in gradual decline recently."
Amphetamines constitute the only class of prescribed psychotherapeutic drugs used outside of medical regimen that have not been showing a recent increase in use. Usage levels today in terms of annual prevalence are about one half what they were at their peak in 1996 for 8th graders, about two thirds what they were that same year among 10th graders, and about three quarters of the more recent peak level (in 2002) for 12th graders. The 8th graders showed a further 0.3 percentage point decline in annual prevalence this year, and the 12th graders a further 0.5 percentage point decline (both nonsignificant).
Over-the-counter cough and cold medications
In 2006, the study included a new question on the use of over-the-counter cough or cold medicines for the explicit purpose of getting high. The drugs in these classes that are abused usually contain dextromethorphan, a cough suppressant, which can cause alterations of consciousness and mood when taken in high doses.
Street names for these drugs include "DXM," "Dex," and "skittles." The proportions of students reporting having used these drugs during the prior year for the purpose of getting high were 4 percent, 5 percent, and 7 percent in grades 8, 10, and 12. In other words, about one in every 25 five 8th graders abused cough or cold medications fairly recently, as did about one in every 14 12th graders.
Because these drugs are available over the counter, students may not fully recognize the dangers of using them.
"If the dangers of using these drugs receive more attention in the media I would expect that their popularity to fade somewhat," Johnston said.
Trends in alcohol use
Among 8th graders, 30-day prevalence of alcohol use has declined by more than one-third since its peak level in 1996. Among 10th and 12th graders, the proportional declines from recent peaks have been smaller" one-sixth among 10th graders since 2000 and one-seventh among 12th graders since 1997.
Last year nearly all prevalence measures for alcohol use and self-reported drunkenness showed some continuing decline in all grade levels, with a number of them reaching statistical significance.
This year, however, only 12th graders showed any further decline in 30-day prevalence of alcohol use (-1.7 percentage points to 43.5 percent, a nonsignificant decline); and there was no further decline in any grade in the 30-day prevalence of self-reported drunkenness. This suggests that the decline in alcohol use may be over in the younger grades but continuing in 12th grade for awhile longer as a result of a cohort effect working itself up the age scale. (There were also statistically significant declines this year among 12th graders in their lifetime and annual prevalence rates.)
In 2006, the prevalence of being drunk at least once in the prior month stands at 6 percent of the 8th graders, 19 percent of the 10th graders, and 30 percent of the 12th graders.
Despite these impressively high rates, they actually reflect proportional declines from recent peaks of more than one third among 8th graders, one fifth among 10th graders, and one eighth among 12th graders. There was no further improvement this year, however.
Past 30-day prevalence of the use of flavored alcoholic beverages (sometimes called " alcopops" or " malternatives" ) was first measured in all three grades in 2004. In 2006 it is at slightly lower levels in all grades, having declined by 1.1 percentage points among 8th graders (not significant) and 3.7 percentage points among 12th graders (not significant).
Use of this class of beverages does not seem to be rapidly expanding, as some had feared. If anything, there appears to have been some decline in the use of these beverages by teens.
Cigarette smoking trends
Trends in the use of cigarettes and other tobacco products are the subject of a separate press release being issued simultaneously with the present one. (It is available on the study's Web site, www.monitoringthefuture.org.) The 30-day smoking rates continued a very gradual decline in all three grades in 2006" statistically significant for the three grades combined, but not for any one grade. Again, the largest declines are now occurring among the 12th graders.
Monitoring the Future has been funded under a series of competing, investigator-initiated research grants from the National Institute on Drug Abuse, part of the National Institutes of Health. Surveys of nationally representative samples of American high school seniors were begun in 1975, making the class of 2006 the 32nd such class surveyed. Surveys of 8th and 10th graders were added to the design in 1991, making the 2006 nationally representative samples the 16th such classes surveyed. The sample sizes in 2006 are 17,026 eighth graders in 151 schools, 16,620 tenth graders in 123 schools, and 14,814 twelfth graders in 136 schools, for a total of 48,460 students in 410 secondary schools. The samples are drawn separately at each grade level to be representative of students in that grade in public and private secondary schools across the coterminous United States. Schools are selected with probability proportionate to their estimated class size.
The findings summarized here will be published in the forthcoming volume: Johnston, L. D., O'Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2007). Monitoring the Future national results on adolescent drug use: Overview of key findings, 2006. (NIH Publication No. [yet to be assigned].) Bethesda MD: National Institute on Drug Abuse.