Overall teen drug use continues gradual decline; but use of inhalants rises

 

Cigarette smoking among American teens continues eight-year decline  

Monitoring the Future website  

ANN ARBOR—The proportion of American 8th-, 10th-, and 12th-grade students who reported using any illicit drug in the prior 12 months continued a gradual decline in 2004, according to the latest national survey of 50,000 students in the Monitoring the Future study.

This decline has been occurring since 1996 among the nation’s 8th-grade students, among whom there has now been a one-third decline in annual prevalence of using any illicit drug (from 23.6 percent in 1996 to 15.2 percent in 2004).   This is the third year of decline among the 10th and 12th graders, following some years of stability in use.  

In 2004, the proportions indicating any use of an illicit drug in the prior 12 months were 15 percent, 31 percent, and 39 percent in grades 8, 10, and 12 respectively. The proportions ever having tried an illicit drug in their lifetime were 22 percent, 40 percent, and 51 percent, respectively.

Drugs showing some decline in use

Marijuana—by far the most widely used of the illicit drugs—also showed a decline in 2004, with small, not statistically significant declines occurring in all grades. (The same was true in 2003.)    Since the recent peak year of 1996, there has been a more than one-third (36 percent) decline in the annual prevalence of marijuana use among 8th graders, from 18.3 percent to 11.8 percent in 2004.   Tenth and 12th graders showed a more modest decline, mostly because their use held steady from 1997 to 2001, before beginning to decline. Across the three grades combined, 30-day prevalence of any illicit drug use, as well as marijuana use, specifically, dropped by statisticallysignificant amounts between 2003 and 2004.

Over the past two years, there has been an increase in the proportion of students seeing marijuana use as dangerous; this change in beliefs may well explain some of the recent gradual decline in use. Personal disapproval of marijuana use increased some this year as well.

“Quite possibly, the media campaign aimed at marijuana use that has been undertaken by the White House Office of Drug Control Policy, in collaboration with the Partnership for a Drug Free America, has been having its intended effect,” said University of Michigan researcher Lloyd Johnston, the study’s principal investigator. “I am not aware of any other social influence process that could explain these changes in how young people view marijuana.”

The proportion of students saying that it would be easy for them to get marijuana, if they wanted some, has been declining gradually in recent years, and it continued to decline this year as well.

Monitoring the Future involves annual surveys of approximately 50,000 secondary school students in roughly 400 schools nationwide. The samples are nationally representative of all students enrolled in grades 8, 10, and 12 in public and private secondary schools in the coterminous United States. The study is now in its 30th year, having begun surveys of high school seniors in 1975.

It is sponsored by the National Institute on Drug Abuse under a series of competing research grants made to the University of Michigan’s Institute for Social Research. The authors of the report are Johnston, Patrick O’Malley, Jerald Bachman, and John Schulenberg—all psychologists and research professors at U-M. Trends in Annual Prevalence of an Illicit Drug Use Index – Eighth, Tenth and Twelfth graders See all charts in PDF format

The proportion of students reporting having used any illicit drug other than marijuana fell less than did marijuana in 2004. In fact, the indicator for 12th graders showed a small increase.   There are many drugs in this class, however, some of which showed a decrease in use and many of which held steady. Among those showing modest declines this year were ecstasy, amphetamines, methamphetamine, PCP, Vicodin, ketamine and steroids.

“Because ecstasy use had been in a pattern of sharp increase in recent years, its turnaround two years ago and continued decline in all three grades last year were very important developments,” Johnston said. “Over just that two-year interval, the annual prevalence of ecstasyuse fell by more than half among both 10th and 12th graders.”  

In 2004, the downward trend continued, but at a very much decelerated rate. In other words, the declines are much smaller and none reached statistical significance this year, even though all three grades continued to show some decline in use. (The one-year decline when all three grades are combined is statistically significant.)

“A considerable rise in the perceived risks of using ecstasy no doubt accounts for most of the turnaround in its use,” Johnston said. Perceived risk began to rise a year before the decline in use began, and it has continued to rise since, though the rise also decelerated sharply this year. There has also been increasing disapproval by teens of ecstasy use since 2000, an increase that continued in the upper grades in 2004. As the number of users has declined, somewhat fewer teens see the drug as readily available. Perceived availability declined again in 2004

The use of amphetamines—a class of stimulant drugs that has been in fairly widespread use in the past—has been in a steady decline among 8th graders since 1996; in fact, their annual prevalence of nonmedically supervised use has fallen almost by half since then. The gradual decline continued in 8th grade this year. Among 10th and 12th graders, however, amphetamine use held quite steady through 2002, before finally showing a decline last year. That decline also continued this year among 10th graders, but not among 12th graders, who at 10 percent annual prevalence remain near their recent peak levels of use.

Measures of methamphetamine use were introduced into the study in 1999. Since then, there has been a pattern of declining use in all three grades, which continued this year in the lower two grades. Across the three grades combined, this year’s decline was statistically significant. All three grades now have annual prevalence rates for methamphetamine considerably below what they were in 1999.

Use of PCP, or phencyclidine, has been at low levels for some time, and use fell further in 2004.   In fact, annual use, which is measured only at 12th grade, is now at its lowest level since use was first measured in 1979—0.7 percent in 2004 compared to 7.0 percent in 1979.

Vicodin, a synthetic narcotic pain killer, was found to have quite a high prevalence rate when its use was first measured in 2002; and it showed some (not statistically significant) increase in use at all grade levels in 2003. However, in 2004 there was some (not statistically significant) decline observed in all three grades, more than offsetting last year’s increases. Still, the annual prevalence of use for this narcotic drug remains at 9.3 percent among high school seniors.

Ketamine (known on the street as “special K”) is one of the so-called club drugs. It has not had a particularly high prevalence since it was first measured in 2000, with annual prevalence between 1.0 percent and 2.6 percent across the various grades and years. Since 2002, all three grades have been showing a gradual, steady decline in ketamine use, bringing the rates well below peak levels.   This year the decline in 10th grade reached statistical significance.

Anabolic steroids, often used to enhance strength and musculature, continued into the fourth year of decline among 8th graders and the second year of decline among 10th graders. In both cases, the prevalence rates in 2004 are about one-third lower than they were in the recent peak years. Twelfth graders have not yet exhibited a decline from the peak level of 2.5 percent, possibly because the cohorts of heavier-using 10th graders from a couple of years ago are now in 12th grade.

Drugs holding steady

While the several drugs mentioned above have shown modest declines in 2004, most of the remaining drugs showed little or no systematic change this year, though most of them have shown some decline in recent years. These include LSD, hallucinogens other than LSD taken as a class, crack cocaine, cocaine powder, heroin, narcotics other than heroin taken as a class, tranquilizers, sedatives, “ice” (crystal methamphetamine), Rohypnol and GHB.

The use of LSD has been in decline since 1996 but in particularly steep decline from 2000 through 2003. In 2004 there was little further change, leaving the usage rates for this drug at historically low levels. Generally, attitudes have not moved in a way that could explain the earlier steep drop in use, but perceived availability has.

Hallucinogens other than LSD, taken as a class, have shown no significant change in 2003 or 2004 at any of the three grade levels in terms of the annual prevalence of use. However, this still leaves them near the recent peak levels of use attained since the mid-1980s. The most commonly used drug in this set is psilocybin, derived from a type of mushroom and known on the street as “shrooms.”

The use of crack cocaine also held steady in all three grades this year.   The rates today are somewhat below the recent peaks, reached in the late 1990s.

The use of cocaine powder by teens has not changed a great deal in the last three or four years. Its use is at slightly lower levels than the recent peaks in the late 1990s and at much lower levels than were reached in the mid-1980s during the original cocaine epidemic.

Heroin use showed no change at any grade level in 2004.   In all three grades the rates of use are below where they were at their recent peaks in the late 1990s.

The use of narcotics other than heroin, taken as a class, is reported only for the 12th-grade students.   There is little evidence of any systematic change since 2002 in the prevalence of use of this important class of drugs. However, two specific drugs within the class are showing signs of change this year (with OxyContin possibly increasing and Vicodin possibly decreasing), as is discussed elsewhere in this release.

The use of tranquilizers held fairly steady this year at all three grade levels.

Sedative (including barbiturate) use is reported only for 12th graders. Sedative use had earlier shown a decade-long rise, before leveling for the first time in 2003—a welcome development, according to the investigators. Use in 2004 held about steady.

The use of ice, or crystal methamphetamine, has been measured among seniors since 1990.   Its use rose in the first half of the 1990s but has remained essentially flat at relatively low rates since then. Annual prevalence in 12th grade stands at 2.1 percent in 2004, about where it was in 2003.

Two so-called club drugs, Rohypnol and GHB, showed little systematic change in 2004.   Rohypnol has relatively low annual prevalence rates among secondary school students (between 0.6 percent and 1.6 percent) and showed no change this year at any grade level.   GHB showed no change in 8th graders, a decrease in 10th graders, but an equivalent increase at 12th graders.   Overall, the investigators interpret this pattern as showing no systematic change.

Drugs showing signs of increasing use

Only two drug categories (inhalants and OxyContin) showed evidence of increasing use by teens this year; in the latter case, the increase is modest and confined to a single grade.

Inhalants constitute a class of drugs defined by mode of administration (inhalation) and by the form of the substance being administered (fumes), rather than by their chemical or psychoactive properties.   They encompass a range of substances as diverse as glues, aerosols, butane, paint thinner and nail polish remover.  

Use of inhalants has consistently been highest among 8th graders, likely because these products are inexpensive, legal and easy to obtain, making them more attractive to younger adolescents who have less access to illicit drugs. There was a long and substantial decline in the use of inhalants by students in all three grades after 1995, when the Partnership for a Drug-Free America conducted an anti-inhalant media campaign.  

However, use by 8th graders increased significantly last year, and the investigators called attention to the fact that the use of this class of drugs may be about to rebound. This year inhalant use continued to increase among 8th graders, and for the first time in recent years increased in the upper two grades as well. (The increase in annual prevalence this year for the three grades combined was statistically significant, though no one of the 2004 grade-specific changes was significant.)

“The proportion of young people who believe it is dangerous to use inhalants has declined among both 8th and 10th graders over the past three years, which quite possibly explains the rebound in use,” Johnston said.   “This turnaround in their use continues to suggest the need for greater attention to the dangers of inhalant use in our media messages and in-school prevention programs.”

OxyContin falls into the general class of narcotic drugs and within the more specific class of oxycodone. Questions about its use were added to the study in 2002 because of widespread and growing concern about its use. Last year, Monitoring the Future reported some increase in annual prevalence in OxyContin use at all three grade levels, though not one of the changes reached statistical significance.   

In 2004, there has been no further change in the lower two grades, but among 12th graders annual prevalence rose further—moving from 4.0 percent in 2002, to 4.5 percent in 2003, to 5.0 percent in 2004.   At present, the annual prevalence rates for grades 8, 10, and 12 are 1.7 percent, 3.5 percent, and 5.0 percent, respectively.   (This year’s increase in twelfth grade was not by itself statistically significant, but the 2002-2004 increase in Oxycontin use for the three grades combined is significcant.)

“Considering the addictive potential of this drug, which is a powerful synthetic narcotic used to control pain, we think that these are disturbingly high rates of involvement by American young people,” Johnston said.   He points out that heroin, by way of contrast, has an annual prevalence rate of 1 percent or less in all three grades.

Alcohol use by teens

In addition to the many illicit drugs, the Monitoring the Future study also monitors the use of some substances that are legally sold—in particular, cigarettes and alcohol. A separate news release issued simultaneously with this one deals with cigarettes, so the findings will not be repeated here.

The story for alcohol use by American teens is a mixed one in 2004. In the 2002 survey, the first one after 9/11, there were drops in several indicators of alcohol use at all grade levels.   In general, that improvement has held in the lower two grades surveyed, though there has not been much further decline since then. Clearly, there has been a statistically significant decline in all measures of drinking at all three grade levels since 2001.

However, in 2004, among the 12th graders, drinking and drunkenness did not continue to decline; in fact, most drinking measures showed some increase in use (though none of the increases reached statistical significance). “We will have to wait for another year to see if this increase in 12th grade is a real one, or just a blip in the data,” Johnston said.

Last year, the study reported for the first time on teen use of flavored alcoholic beverages and found a fairly high prevalence of use of such drinks in the previous year. This year’s reading on the same question showed virtually no change in the annual prevalence statistic, which was 55.2 percent in 2003 and 55.8 percent in 2004.

Overview

In summary, most of the movement this year in teen substance use has been in a downward direction, but generally the declines have been quite modest. Quite a number of drugs showed little or no change in use in 2004 compared to 2003, though most of them are at levels below their recent peak rates. The continuation of a decline in marijuana use, and the hardening of attitudes about it, is one of the more important developments this year, the investigators said.  

The resurgence of inhalant use in all three grades, but particularly among the younger students—the 8th graders—is one of the more troublesome findings this year. “The continued rise in OxyContin use among high school seniors—even though it is not a statistically significant one—continues to concern us,” Johnston said, “particularly given the relatively high prevalence rate already attained by this highly addictive narcotic drug.”

Monitoring the Future has been funded under a series of competing, investigator-initiated research grants from the National Institute on Drug Abuse.   Surveys of nationally representative samples of American high school seniors were begun in 1975, making the class of 2004 the 30th such class surveyed.   Surveys of 8th and 10th graders were added to the design in 1991, making the 2004 nationally representative samples the 14th such classes surveyed. The sample sizes in 2004 are 17,413 8th graders located in 147 schools, 16,839 10th graders located in 131 schools, and 15,222 12th graders located in 128 schools, for a total of 49,474 students in 406 secondary schools overall. The samples are drawn to be representative of students in private and public secondary schools across the 48 coterminous United States, selected with probability proportionate to estimated class size, to yield separate, nationally representative samples of students from each of the three grade levels.

The findings summarized here will be published in the forthcoming volume:   Johnston, L. D., O’Malley, P. M., Bachman, J. G., & Schulenberg, J. E. (2005). Monitoring the Future national results on adolescent drug use: Overview of key findings, 2004.  (NIH Publication No. [yet to be assigned].) Bethesda MD: National Institute on Drug Abuse.

 

Meyer