Monitoring the Future: National Results on Adolescent Drug Use: Overview of Key Findings

Abstract

Back to table of contents Previous article INFLUENTIAL PUBLICATIONFull AccessMonitoring the Future: National Results on Adolescent Drug Use: Overview of Key FindingsLloyd D. Johnston, Ph.D., Patrick M. O’Malley, Ph.D., and Jerald G. Bachman, Ph.D.Lloyd D. JohnstonSearch for more papers by this author, Ph.D., Patrick M. O’MalleySearch for more papers by this author, Ph.D., and Jerald G. BachmanSearch for more papers by this author, Ph.D.Published Online:1 Apr 2003https://doi.org/10.1176/foc.1.2.213AboutSectionsPDF/EPUB ToolsAdd to favoritesDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InEmail This report presents an overview of the key findings from the Monitoring the Future study’s 2001 nationwide survey of 8th, 10th, and 12th grade students. A particular emphasis is placed on recent trends in the use of licit and illicit drugs. Trends in the levels of perceived risk and personal disapproval associated with each drug—which this study has shown to be particularly important in explaining trends in use—are also presented, as well as trends in perceived availability of the various drugs.Monitoring the Future (MTF), begun in 1975, is a long-term study of American adolescents, college students, and adults through age 40. It is conducted by the University of Michigan’s Institute for Social Research and is supported under a series of investigator-initiated, competing research grants from the National Institute on Drug Abuse.Following this introduction, there is a synopsis of methods used and an overview of the key results from the 2001 survey. This general synopsis is followed by a section for each individual drug class, providing graphs that show trends in the overall proportions of students at each grade level (a) reporting use, (b) seeing a “great risk” associated with its use, (c) disapproving its use, and finally, (d) saying that they could get the drug “fairly easily” or “very easily.” The trends are presented for the interval 1991–2001 for all grades, and for 1975–2001 for the 12th graders.The tables at the end of [the original] report provide the statistics underlying the graphs; in addition they present data on lifetime, 30-day, and (for selected drugs) daily prevalence. [Prevalence refers to the proportion or percentage of the sample reporting use of the given substance on one or more occasions in a given time interval—e.g., lifetime, past 12 months, or past 30 days. The prevalence of daily use usually refers to use on 20 or more occasions in the past 30 days.] They present these prevalence statistics only for the 1991–2001 interval, but statistics on 12th graders are available for longer intervals in other publications from the study. The tables indicate for each prevalence period which of the one-year changes between 2000–2001 are statistically significant.A more extensive analysis of the study’s findings on secondary school students may be found in a volume to be published later in 2002. [The most recent publication in this series is: Johnston LD, O’Malley PM, Bachman JG: Monitoring the Future national survey results on drug use, 1975–2000: Volume I, Secondary school students. NIH Publication No 01-4924. Bethesda, MD, National Institute on Drug Abuse, 2001.] The volumes in this series also contain a more complete description of the study’s methodology as well as an appendix on how to test the significance of differences between groups or for the same group over time. The most recent such volume is always posted on the study’s Web site.The study’s findings on American college students and young adults are not covered in this early Overview report because the 2001 data are not available at the time of this writing. They are covered in a second series of volumes that will be updated later this year. [The most recent in this series is: Johnston LD, O’Malley PM, Bachman JG: Monitoring the Future national survey results on drug use, 1975–2000: Volume II, College students and adults ages 19–40. NIH Publication No 01-4925. Bethesda, MD, National Institute on Drug Abuse, 2001. It may be ordered from the National Clearinghouse for Alcohol and Drug Information; or it may be viewed on the study’s Web site at www.monitoringthefuture.org.] Volumes in these two annual series are available from the National Clearinghouse for Alcohol and Drug Information at (800) 729-6686 or by e-mail at [email protected].Further information on the study, including its latest press releases, a listing of all publications, and the text of many of them, may be found on the Web at www.monitoringthefuture.org.Study design and methodsAt the core of Monitoring the Future is a series of large, annual surveys of nationally representative samples of students in public and private secondary schools throughout the coterminous United States. Every year since 1975 a national sample of 12th graders has been surveyed. Beginning in 1991, the study was expanded to include comparable national samples of 8th graders and 10th graders each year.Sample sizesThe 2001 sample sizes were 16,800, 14,300, and 13,300 in 8th, 10th, and 12th grades, respectively. In all, about 44,300 students in 424 schools participated. Because multiple questionnaire forms are administered at each grade level, and because not all questions are contained in all forms, the number of cases upon which a particular statistic is based can be less than the total sample. The tables at the end of [the original report] contain the sample sizes associated with each statistic.Field proceduresUniversity of Michigan staff members administer the questionnaires to students, usually in their classrooms during a regular class period. Participation is voluntary. Questionnaires are self-completed and formatted for optical scanning. In 8th and 10th grades the questionnaires are completely anonymous, and in 12th grade they are confidential (to permit the longitudinal follow-up of a random sub-sample of participants for some years after high school in a panel study).MeasuresA standard set of three questions is used to determine usage levels for the various drugs (except for cigarettes and smokeless tobacco). For example, we ask, “On how many occasions (if any) have you used LSD (‘acid’) . . . (a) . . . in your lifetime?, (b) . . . during the past 12 months?, (c) . . . during the last 30 days?” Each of the three questions is answered on the same answer scale: 0 occasions, 1–2, 3–5, 6–9, 10–19, 20–39, and 40 or more occasions. For the psychotherapeutic drugs (amphetamines, barbiturates, tranquilizers, and opiates other than heroin), respondents are instructed to include only use “. . . on your own—that is, without a doctor telling you to take them.” A similar qualification is used in the question on use of anabolic steroids. For cigarettes, respondents are asked two questions about use: “Have you ever smoked cigarettes?” (the answer categories are “never,” “once or twice,” and so on) and “How frequently have you smoked cigarettes during the past 30 days?” (the answer categories are “not at all,” “less than one cigarette per day,” “one to five cigarettes per day,” “about one-half pack per day,” etc.). Parallel questions are asked about smokeless tobacco.Alcohol use is measured using the three questions illustrated above for LSD. A parallel set of three questions asks about the frequency of being drunk. Another question asks, for the prior two-week period, “How many times have you had five or more drinks in a row?” Perceived risk is measured by a question asking, “How much do you think people risk harming themselves (physically or in other ways), if they . . .” “. . . try marijuana once or twice,” for example. The answer categories are “no risk,” “slight risk,” “moderate risk,” “great risk,” and “can’t say, drug unfamiliar.” Disapproval is measured by the question, “Do YOU disapprove of people doing each of the following?” followed by “trying marijuana once or twice,” for example. Answer categories are “don’t disapprove,” “disapprove,” “strongly disapprove,” and (in 8th and 10th grades only) “can’t say, drug unfamiliar.” Perceived availability is measured by the question, “How difficult do you think it would be for you to get each of the following types of drugs, if you wanted some?” Answer categories are “probably impossible,” “very difficult,” “fairly difficult,” “fairly easy,” “very easy” and (in 8th and 10th grades only) “can’t say, drug unfamiliar.”Overview of key findingsThe surveys of 8th, 10th, and 12th grade students in the United States conducted in 2001 generated mixed results, as did the 1999 and 2000 surveys.Drugs increasing in useThe primary drug showing an increase in 2001 was ecstasy (MDMA), which had been rising sharply since 1998. (A similar increase had been documented among the 19- to 26-year-olds in the follow-up surveys in the study, at least through 2000.) While there was further increase in ecstasy use observed in 2001 among the secondary school students, the rate of increase began to fall off, quite possibly due to a sharp increase in the proportion of students seeing this drug as dangerous. [The 2000–2001 increases in use were not statistically significant for individual grades, but were significant across the three grades combined. Thirty-day prevalence showed a less consistent pattern of change this year, possibly reflecting a very recent turnaround in use in 12th grade; but another year of data is needed to clarify this.] The proportion of 12th graders (8th and 10th graders were not asked this question until 2001) saying they see a “great risk” in trying ecstasy jumped 8 percentage points between 2000 and 2001. However, special analyses indicate that the proportion of the schools in the MTF national samples having at least one respondent who has ever used ecstasy was still increasing in 2001. Thus the drug is still diffusing to new communities, which may have been more than enough to offset the effects of the increase in perceived risk. Reported availability of ecstasy continued to rise quite dramatically, perhaps in part due to this diffusion process. The use of anabolic steroids increased significantly among 12th graders this year, perhaps reflecting a cohort effect, since steroid use had risen fairly sharply among the younger students in the prior two years. However, there was no further increase in steroid use among the 8th or 10th graders in 2001.Drugs declining in useIn contrast to the increase in ecstasy, a number of other drugs showed evidence of some decline in 2001. One of the most important such declines involved heroin, which had been at or near peak levels in recent years, due in large part to the ascent of using heroin without a needle in the early 1990s. Eighth graders showed some decline in heroin use in 2000, and the 10th and 12th graders showed their first decline in use in 2001. Virtually all of this improvement occurred in the use of heroin without a needle (i.e., in smoking or snorting it).Of clear and particular importance, cigarette smoking by adolescents in all three grades continued to decline sharply in 2001, extending an improvement that began after 1996 (among 8th and 10th graders) or 1997 (among 12th graders). Daily smoking among 8th graders has now fallen almost by half since the recent peak rate in 1996—offsetting the sharp increase in smoking seen in this age group in the early 1990s. A specialized type of flavored cigarette called “bidis,” imported from India, threatened to make inroads into the American market. However, the use of these cigarettes, which was not very widespread in 2000—the first year on which we had prevalence estimates—actually declined appreciably in 2001. The third class of tobacco product on which we have estimates is smokeless tobacco, the use of which had declined considerably in recent years, but did not decline any further in 2001.Some of the illicit drugs other than heroin showed continuing declines in 2001, though many of those were gradual and did not reach statistical significance for the one-year interval of 2000–2001. These included LSD, the annual prevalence of which dropped significantly in 10th grade and nonsignificantly in 8th grade in 2001. (There was no further change in 12th grade.) All three grades have annual prevalence rates of LSD use that are now 25% to 41% lower than the recent peak in 1996; these represent important cumulative declines. Somewhat surprisingly, these declines have not been accompanied by increases in perceived risk, leading us to conclude that another drug may be displacing LSD as a drug of choice. Ecstasy seems the most likely candidate, since it is also used for its hallucinogenic effects and is the only drug on the rise at present. In fact, the perceived risk of LSD use actually has been falling (as has the disapproval of its use, especially among 8th graders), and this may be setting the stage for a comeback of LSD use at some future time.Inhalant use, which began to decline from peak levels in 1996 in all three grades, continued to decline in 2001 (though only the 12th grade one-year decline was statistically significant). The annual prevalence rates for inhalants are now down from their 1995 peaks by 29%, 31%, and 44% in grades 8, 10, and 12, respectively. Again, these are important cumulative improvements.The use of crack and powdered cocaine are both off modestly from their peak levels in the 1990s (which were far below the peak levels reached in the mid-1980s); but only cocaine powder showed a significant decline in 2001 (only in 10th grade).There has been some modest decrease in the 30-day prevalence of alcohol use among students at all three grades since the recent peaks reached in 1996 or 1997, though neither the increase before the peak nor the decrease thereafter has amounted to much change. The gradual decreases continued this year, though none reached statistical significance. Reports of being drunk also declined in grades 8 and 10 this year.Drugs holding steadyThe use of marijuana held steady at rates only slightly below the peak rates reached in 1997 among 10th and 12th graders. Eighth graders, who had shown a slow steady decline in marijuana use after their recent peak in 1996, also showed no further improvement this year. Because marijuana use remained unchanged, so did the index of the use of any illicit drug, which is driven mostly by marijuana—the most prevalent of the illicit drugs.Other drugs that showed no systematic changes in 2001, in addition to marijuana, were hallucinogens other than LSD, narcotics other than heroin (reported only for 12th graders), heroin with a needle, amphetamines, methamphetamine, crystal methamphetamine, barbiturates (reported only for 12th graders), and three of the so-called “club drugs”—Rohypnol, GHB, and Ketamine.It is noteworthy that the downturns in the 1990s started first and have been the most sustained among the 8th graders for a number of drugs.Reasons for the diverging trendsThe wide divergence in the trajectories of the different drugs in this single year helps to illustrate the point that, to a considerable degree, the determinants of use are often specific to the drugs. These determinants include both the perceived benefits and the perceived risks that young people come to associate with each drug.Unfortunately, word of the supposed benefits of using a drug usually spreads much faster than information about the adverse consequences. The former takes only rumor and a few testimonials, the spread of which has been hastened greatly by the electronic media and the Internet. The latter—the perceived risks—usually take much longer for the evidence (e.g., of death, disease, overdose reactions, addictive potential) to cumulate and then to be disseminated. Thus, when a new drug comes onto the scene, it has a considerable “grace period” during which its benefits are alleged and its consequences are not yet known. We have argued that ecstasy has been the beneficiary of such a grace period until this year, when perceived risk for this drug finally rose sharply.Implications for preventionTo some considerable degree, prevention must occur drug by drug, because knowledge of the adverse consequences of one drug will not necessarily generalize to the use of other drugs. Many of young people’s beliefs and attitudes are specific to the drug. A review of the charts in this [overview] on perceived risk and disapproval for the various drugs—attitudes and beliefs which we have shown to be important in explaining many drug trends over the years—will amply illustrate this contention. These attitudes and beliefs are at quite different levels for the various drugs and, more importantly, often trend differently over time.New drugs help to keep the epidemic goingAnother point well illustrated by this year’s results is the continuous flow of new drugs introduced onto the scene or of older ones being “rediscovered” by young people. Many drugs have made a comeback years after they first fell from popularity, often because young people’s knowledge of their adverse consequences faded as generational replacement took place. We call this process “generational forgetting.” Examples of this include LSD and methamphetamine, two drugs used widely in the beginning of the broad epidemic of illicit drug use, which originated in the 1960s. Heroin, cocaine, PCP, and crack are some others that made a comeback in the 1990s after their initial popularity faded.As for newer drugs coming onto the scene, examples include the nitrite inhalants and PCP in the 1970s, crack and crystal methamphetamine in the 1980s, and Rohypnol, GHB, and ecstasy in the 1990s. The perpetual introduction of new drugs (or of new forms of taking older ones, as illustrated by crack, crystal methamphetamine, and non-injected heroin) helps to keep the country’s “drug problem” alive. Because of the lag times described previously, during which evidence of adverse consequences must cumulate and be disseminated before they begin to deter use, the forces of containment are always playing “catch up” with the forces of encouragement and exploitation.Where are we now?As the country begins the 21st century, clearly the problems of substance abuse remain widespread among American young people. Today over half (54%) have tried an illicit drug by the time they finish high school. Indeed, if inhalant use is included in the definition of an illicit drug, more than a third (35%) have done so as early as 8th grade—when most students are only 13 or 14 years old. Three out of ten (29%) have used some illicit drug other than marijuana by the end of 12th grade, and two of those three (20% of all 12th graders) have done so in just the 12 months prior to the survey.Cigarettes and alcoholThe statistics for use of the licit drugs, cigarettes and alcohol, are also a basis for considerable concern. Nearly two-thirds (61%) of American young people have tried cigarettes by 12th grade, and almost a third (30%) of 12th graders are current smokers. Even as early as 8th grade, nearly four in every ten students (37%) have tried cigarettes, and one in eight (12%) already has become a current smoker. Fortunately, we have seen some real improvement in these smoking statistics over the last four or five years, following a dramatic increase in these rates earlier in the 1990s.Cigarette use reached its recent peak in 1996 at grades 8 and 10, capping a rapid climb of some 50% from the 1991 levels (when data first were gathered on these grades). Since 1996, current smoking in these grades has fallen off considerably (by 42% and 30%, respectively), including the further decline in 2001. In 12th grade, peak use occurred a year later (1997), from which there has been a more modest decline of 19%. Overall increases in perceived risk and disapproval of smoking appear to be contributing to this downturn. (See the section on cigarettes for more detail.)Smokeless tobacco use has also been in decline in recent years. Concentrated among males, like steroid use, it has shown fair proportional declines.Alcohol use remains extremely widespread among today’s teenagers. Four out of every five students (80%) have consumed alcohol (more than just a few sips) by the end of high school; and about half (51%) have done so by 8th grade. In fact, nearly two-thirds (64%) of the 12th graders and nearly a quarter (23%) of the 8th graders in 2001 report having been drunk at least once in their life. To a considerable degree, alcohol trends have tended to parallel the trends in illicit drug use. These trends include some modest increase in binge drinking (defined as having five or more drinks in a row at least once in the past two weeks) in the early part of the 1990s, but a proportionally smaller increase than was seen for most of the illicit drugs. Fortunately, binge drinking rates leveled off three or four years ago, just about when the illicit drugs began to turn around.Any illicit drug useIn the remainder of this report, separate sections are provided for each of the many classes of illicit drugs, but we begin by considering the proportions of American adolescents who use any illicit drug, regardless of type. Monitoring the Future routinely reports three different indexes of illicit drug use—an index of “any illicit drug use,” an index of the use of “any illicit drug other than marijuana,” and an index of the use of “any illicit drug including inhalants.” In this section we discuss only the first two; the statistics for the third may be found in [Table 1 in the original report; footnote 1 to Tables 1 through 3 provides the exact definition of “any illicit drug”].In order to make comparisons over time, we have kept the definitions of these indexes constant, even though some new substances appear as time passes. The index levels would be little affected by the inclusion of these new substances, however, prim-arily because almost all users of them are also using the more prevalent drugs included in the indexes. The major exception has been inhalants, the use of which is quite prevalent in the lower grades. Thus, after the lower grades were added to the study in 1991, a special index was added that includes inhalants.Trends in useIn the last third of the twentieth century, young Americans achieved extraordinary levels of illicit drug use, either by historical comparisons in this country or by international comparisons with other countries. The trends in lifetime use of any illicit drug are given in the first panel (Figure 1)[of the Trends in Illicit Drug Use charts]. [This is the only set of figures in this volume presenting lifetime use statistics. For other drugs, lifetime statistics may be found in the tables at the end of the original report.] By 1975, when the study began, the majority of young people (55%) had used an illicit drug by the time they left high school. This figure rose to two-thirds (66%) by 1981, before a long and gradual decline to 41% by 1992—the low point. Today, the proportion is back to 54%, after a period of considerable rise in the 1990s. The comparable trends for annual, as opposed to lifetime, prevalence appear in the second (upper right) panel. They show a gradual and continuing falloff after 1996 among 8th graders. Peak rates were reached in 1997 in the two upper grades, but there has been no further decline since 1998.Because marijuana is so much more prevalent than any other illicit drug, trends in its use tend to drive the index of “any illicit drug use.” For this reason we have an index excluding marijuana use, showing the proportion of these populations willing to use the other, so-called “harder,” illicit drugs. The proportions using any illicit drug other than marijuana are in the third panel (lower left). In 1975 over one-third (36%) of 12th graders had tried some illicit drug other than marijuana. This figure rose to 43% by 1981, followed by a long period of decline to a low of 25% in 1992. Some increase followed in the 1990s, as the use of a number of drugs rose steadily, and it reached 30% by 1997. (In 2001 it was 29%.) The fourth panel presents the annual prevalence data for the same index, which shows a pattern of change over the past few years similar to the index of any illicit drug use.Overall, these data reveal that, while use of individual drugs (other than marijuana) may fluctuate widely, the proportion using any of them is much less labile. In other words, the proportion of students prone to using such drugs and willing to cross the normative barriers to such use changes more gradually. The usage rate for each individual drug, on the other hand, reflects many, more rapidly changing determinants specific to that drug: how widely its psychoactive potential is recognized, how favorable the reports of its supposed benefits are, how risky the use of it is seen to be, how acceptable it is in the peer group, how accessible it is, and so on.MarijuanaMarijuana has been the most widely used illicit drug for the 26 years of this study. Marijuana can be taken orally, mixed with food, and smoked in a concentrated form as hashish—the use of which is much more common in Europe. However, nearly all the consumption in this country involves smoking it in rolled cigarettes (“joints”), in pipes or, more recently, in hollowed-out cigars (“blunts”).Trends in useAnnual marijuana use peaked at 51% among 12th graders in 1979, following a rise that began during the 1960s. (Figure 2) Then, use declined fairly steadily for 13 years, bottoming at 22% in 1992—a decline of more than half. The 1990s, however, saw a resurgence of use. After a considerable increase in the 1990s (one that actually began among 8th graders a year earlier than among 10th and 12th graders), annual prevalence rates peaked in 1996 at 8th grade and in 1997 at 10th and 12th grades. There has been some very modest decline since those peak levels, more so among the 8th graders, but no one-year change was significant in either 2000 or 2001.Perceived riskThe amount of risk associated with using marijuana fell during the earlier period of increased use and again during the more recent resurgence of use in the 1990s. Indeed, at 10th and 12th grades, perceived risk began to decline a year before use began to rise in the upturn of the 1990s, making perceived risk a leading indicator of change in use. (The same may have happened at 8th grade, as well, but we do not have data starting early enough to check that possibility.) The decline in perceived risk halted in 1996 in 8th and 10th grades, and use began to decline a year or two later. Again, perceived risk was a leading indicator of change in use.DisapprovalPersonal disapproval of marijuana use slipped considerably among 8th graders between 1991 and 1996, and among 10th and 12th graders between 1992 and 1997. For example, the proportions of 8th, 10th, and 12th graders, respectively, who said they disapproved of trying marijuana once or twice fell by 17, 21, and 19 percentage points over those intervals of decline. Since then there has been some modest increase in disapproval among 8th graders, but not much among 10th and 12th graders.AvailabilitySince the study began in 1975, between 83% and 90% of every senior class have said that they could get marijuana fairly easily or very easily if they wanted some; therefore, it seems clear that this has remained a highly accessible drug. Since 1991, when data were also available for 8th and 10th graders, we have seen that marijuana is considerably less accessible to younger adolescents. Still, in 2001 nearly half of all 8th graders (48%) and more than three-quarters of all 10th graders (77%) reported it as being accessible. This compares to 89% for seniors.As marijuana use rose sharply in the early and mid-1990s, reported availability increased as well, perhaps reflecting the fact that more young people had friends who were users. Availability peaked for 8th and 10th graders in 1996 and has shown some falloff since, particularly in 8th grade. Availability peaked a bit later for 12th graders. There has been no further decline in availability in the last couple of years in the upper grades, nor in 2001 in grade 8.InhalantsInhalants are any gases or fumes that can be inhaled for the purpose of getting high. These include many household products, the sale and possession of which is perfectly legal, including such things as airplane glue, nail polish remover, gasoline, solvents, butane, and propellants used in certain commercial products, such as whipped cream dispensers. Unlike nearly all other classes of drugs, their use is most common among younger adolescents and tends to decline as youngsters grow older. The early use of inhalants may reflect the fact that many inhalants are cheap, readily available, and legal. The decline in use with age no doubt reflects their coming to be seen as “kids’ drugs.” In addition, a number of other drugs become available to older adolescents, who also are more able to afford them.Trends in useAccording to the long-term data from 12th graders, inhalant use (excluding the use of nitrite inhalants) rose gradually for some years, from 1976 to 1987. (Figure 3) This rise in use was somewhat unusual in that most other forms of illicit drug use were in decline during the 1980s. Use rose among 8th and 10th graders from the time data were first gathered on them, 1991, through 1995, and also rose among 12th graders from 1992 to 1995. All grades exhibited a steady decline in use through 1999, though it halted briefly at 10th and 12th grades in 2000, before resuming in 2001. In 2001, inhalant use dropped significantly for 12th grade.Perceived riskOnly 8th and 10th graders have been asked questions about the degree of risk they associate with inhalant use. Relatively low proportions of them think that there is a “great risk” in using an inhalant once or twice, although there was an upward shift in this belief between 1995 and 1996, and again in 2001 when si