University of Michigan 412 Maynard St. Ann Arbor, MI 48109-1399
December 18, 1998 (10)
Contact: Diane Swanbrow, (734) 647-4416 [email protected] www.isr.umich.edu/src/mtf/
Drug use by American young people begins to turn downward.
ANN ARBOR---Reporting on the 1998 national survey results from the Monitoring the Future Study of American secondary school students, University of Michigan scientists conclude that illicit drug use by this population is finally heading down after six years of steady increases.
"The improvement so far is very modest," notes Lloyd D. Johnston, the principal investigator of the study and a research scientist at the U-M Institute for Social Research. "But at least the troublesome trends observed through most of the 90s have begun to reverse direction." All three grades have shown some decline in the proportion of students who reported using any illicit drug during the 12 months prior to the survey. This represents the second year of decline among eighth-graders and the first year of decline for the 10th- and 12th-graders. (Both the two-year decline for eighth-graders and the one-year decline for 10th-graders are statistically significant.) The investigators note that eighth-graders were the first to exhibit an upturn in use at the beginning of the 90s, and they also were the first to exhibit this recent downturn (Figure 1).
In the spring of each year the study surveys nationally representative samples of students in the eighth-, 10th-, and 12th-grades. In 1998, a total of nearly 50,000 students in some 422 public and private secondary schools participated in the study. Trend data over the past 23 years (since 1975) are reported for 12th-graders, and the past 7 years (since 1991) for eighth- and 10th-graders.
Funded under a research grant from the National Institute on Drug Abuse (one of the National Institutes of Health in the U.S. Department of Health and Human Services), the study covers a wide range of substances. Each drug has its own pattern of change, discussed below:
Marijuana, the most widely used of the illicit drugs, accounted for most of the increase in overall illicit drug use during the 90s and it now accounts for much of the observed decrease. There was some gradual downward movement in all three grades in those reporting any use of marijuana in the prior 12 months---that is, in annual prevalence. In fact, this is the second year of decline among eighth-graders. Even though marijuana use is decreasing, it is still widespread. This year, nearly a quarter (22 percent) of all eighth-graders said they had tried marijuana, and about half (49 percent) of all 12th-graders said they had done so.
Johnston and his collaborators, Jerald G. Bachman and Patrick M. O'Malley, have found that certain attitudes and beliefs about a drug---in particular the risk of harm young people see associated with use, and the extent to which they and their friends disapprove of use---play an important role in driving changes in actual use of the drug. The increase in marijuana use in the 90s was accompanied by, and to some extent preceded by, a downturn in the risk perceived to be associated with using that drug. Peer norms against use also weakened. However, Johnston notes, "over the past two years, we saw an end to the decline in the risk that young people associate with marijuana use, and now evidence of some turnaround in this important belief, especially among eighth-graders." Personal disapproval of marijuana use has shown a similar cross-time change (Figure 2).
Stimulants (amphetamines) comprise another class of illicit drugs showing a noticeable turnaround. Use has declined for two years among eighth-graders and for one year among 10th-graders, and leveled among 12th-graders in 1998 (Figure 3). The annual prevalence rates in 1998 were 7.2 percent for eighth- graders (down 0.9 percentage points this year and 1.9 percent over the past two years), 10.7 percent for 10th-graders (down 1.4 percentage points), and 10.1 percent for 12th-graders.
Data on the degree of risk associated with amphetamine use is available only for 12th-graders. It shows that an increase in perceived risk---likely due to recent heavy media coverage of the dangers of methamphetamine---preceded the leveling in use among 12th-graders this year. The proportion of 12th-graders seeing "great risk" in trying amphetamines once or twice rose from 29 percent in 1995 to 35 percent in 1998, with most of that change occurring this year.
Hallucinogens showed a downward movement in all three grades in 1998, although the one-year changes are too small to reach statistical significance. This pattern was seen for hallucinogens generally, and for LSD specifically (Figure 4). Use of MDMA (ecstasy) was down for the second year in a row among 10th- and 12th-graders.
Inhalants---glues, aerosols, butane or solvents which young people typically inhale to get high---continued a pattern of gradual decline that began three years ago, with a jump in the proportion of young people who saw inhalant use as dangerous. Prior to 1995, inhalant use had been increasing for some years (Figure 5).
"The advertising campaign against inhalant use launched in April 1995 by the Partnership for a Drug-Free America, as well as the increased media attention given to the dangers of inhalants, may well have played an important role in bringing about the turnaround in use," concludes Johnston. "Few, if any, other drugs had begun to decline by 1996."
Some categories of illicit drugs did not show an improvement this year; however, none showed a sharp increase:
Heroin. The rise in the use of heroin, which began among teens in the 90s, halted at all three grade levels by 1998 (Figure 6). It actually halted among eighth-graders a year earlier. The risk perceived to be associated with heroin use has risen some over the past several years.
Cocaine. The use of both crack cocaine and powder cocaine rose gradually in the 90s as young people's views of how dangerous they were began to erode (Figures 7-9). In general, crack use continues to show some upward drift in the lower grades in 1998, whereas the use of powder cocaine has now leveled in those grades. And perceived risk for crack, while still declining in the upper grades, has begun to level at eighth-grade---an encouraging sign for the future, according to the investigators (Figures 7-9).
Tranquilizers. The increase in use of tranquilizers in eighth-grade halted in 1998, but use continued its longer-term gradual increase among 10th- and 12th-graders (Table 1b).
Alcohol. The use of alcoholic beverages by American teen-agers had been drifting upward very gradually in recent years as they came to see behaviors such as weekend binge drinking as less and less dangerous. In 1998, however, there was some decline in alcohol use at all three grades, in both annual and monthly prevalence rates. (The declines in 12th-grade were very small and not statistically significant). As with marijuana, this is the first evidence of any decline among 10th- or 12th-grades in a number of years, and it is the second year of decline among eighth-graders (Table 1b). Self-reported drunkenness in the past 12 months showed a comparable pattern of change. Still, despite the very modest improvements, fully one-third (33 percent) of all high school seniors report being drunk at least once in the 30-day interval preceding the survey.
The risk perceived to be associated with weekend binge drinking began to rise two years ago among eighth- and 10th-graders (after having declined for several years), which may help to explain the recent downturn in alcohol use at these grade levels. Among 12th-graders, the decline in perceived risk was halted in 1998.
"In sum, we seem to be in the middle of a gradual turnaround in young people's use of most kinds of illicit drugs, as well as alcohol, following an earlier period of sustained increases," concludes Johnston. "These behaviors sometimes change very slowly, and often only after there has been some reassessment by young people of how dangerous these various drugs are, and how acceptable they are in the peer group. Such a reassessment now appears to be occurring for many drugs, very gradually. This turnaround may be due in part to more young people getting to observe adverse consequences of drug use firsthand as the number of users has risen. It may also be due, in part, to more attention being paid to the drug issue by a number of sectors of society, including community groups, parents, government, and the media. One also hears and sees fewer performers in the music industry singing the praises of drugs than was true in the early 90s, which also could make a real difference for teen-agers."
# # # # #
The study, titled "Monitoring the Future," began in 1975 at the University of Michigan's Survey Research Center with annual surveys of American high school seniors. Beginning in 1991, similar surveys of nationally representative samples of eighth- and 10th-graders have been conducted annually. At each grade level the students are drawn to be representative of all students in public and private secondary schools nationwide. In the spring of the year, they complete self-administered questionnaires given to them in their classrooms by U-M personnel. The 1998 eighth-grade sample contained about 18,700 students in 149 schools, the 10th-grade sample contained about 15,400 students in 129 schools, and the 12th-grade sample contained about 15,800 students in 144 schools. In all, nearly 50,000 students in 422 public and private secondary schools were surveyed in 1998.
Methodological note. For the first time in 1998, in half of the eighth- and 10th-grade schools surveyed, the questionnaires administered were made fully anonymous (as opposed to confidential, but with some identifying information being gathered on a tear-off card). Specifically, the matched half-sample of schools beginning their two-year participation in Monitoring the Future in 1998 received the anonymous questionnaires, while the half-sample participating in the study for their second and final year continued to get the confidential questionnaires. A careful examination of the 1998 results based on the two equivalent half-samples at grade 8 and at grade 10, revealed no effect of this methodological change among 10th-graders, and only a very modest difference in the self-reported rates of alcohol and marijuana use among the eighth-graders (with prevalence rates slightly higher in the anonymous condition). The net effect of this methodological change is to slightly increas! e the eighth-grade prevalence estimates for marijuana and alcohol in 1998 from what they would have been in the absence of such a change in questionnaire administration. For those two drugs, that means that the declines in use in 1998 are slightly understated. In other words, the direction of the change is the same as shown in the tables, but the actual declines are probably slightly larger than those shown. For example, the annual prevalence of marijuana use among eighth-graders is shown to have fallen by 0.8 percentage points between 1997-1998; however, the half-sample of eighth-grade schools receiving exactly the same type of questionnaire that was used in 1997 showed a slightly greater decline of 1.5 percentage points.
# # # # # #
RSS