"In the thirteen-year (2004–2016) combined sample of young adults aged 21–30, 1.5% report having ever used any drug by injection not under a doctor’s orders, and 0.5% reported doing so on 40 or more occasions (Table 4-1a). Thus, about 1 in every 67 respondents has ever used an illicit drug by injection, and about 1 in every 200 respondents reports an extended pattern of use as indicated by use on 40 or more occasions. There is a fair-sized gender difference -- 2.3% of males vs. 0.9% of females indicate ever injecting a drug.
"Marijuana, the most widely used of the illicit drugs, did not show any significant change in annual prevalence this year in any of the three grades, nor in the three grades combined. After rising for several years, the annual prevalence of marijuana has more or less leveled out since about 2010.
" Figure 5-4a and Table 5-5d provide trends in daily marijuana use, defined as using marijuana on 20 or more occasions in the prior 30 days. Among 12th grade students, the 2019 level of 6.4% is the highest level recorded by the survey since 2013. About one in every 16 twelfth grade students in 2019 was a daily or near-daily marijuana user. Daily marijuana use significantly increased in 8th and 10th grade in 2019, to 1.3% and 4.8%, respectively.
" In 2018 for the first time in the history of the survey the majority of 12th grade students did not favor legally prohibiting marijuana use in public places. The proportion of 12th graders who favor legally prohibiting marijuana use in public places decreased by 2 percentage points to 48% in 2018, continuing a long decline since 2008, when 70% favored prohibition. The percentage favoring legal prohibitions against use in private was also at a historic low of 22% in 2018, down from 82% in 1990.
"Annual marijuana prevalence peaked among 12th graders in 1979 at 51%, following a rise that began during the 1960s. 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 (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. After these peak years, use declined among all three grades through 2007 or 2008.
" Substantial differences were found in perceived availability of the various drugs. The percentage of 12th graders reporting it would be fairly easy or easy to get a drug varied from 16% or less for heroin and PCP to above 80% for alcohol, vaping devices, and an e-liquid with nicotine for vaping.
Data Table of Estimated 30-Day Prevalence of Use of Various Drugs for Young People in the US in Grades 8, 10, and 12 Combined, 1998 through 2016, According to the Monitoring The Future Survey
"Crack cocaine use spread rapidly from the early to mid-1980s. Still, among 12th graders, the use of crack remained relatively low during this period (3.9% annual prevalence in 1987). Clearly, crack had quickly attained a reputation as a dangerous drug, and by the time of our first measurement of perceived risk in 1987, it was seen as the most dangerous of all drugs. Annual prevalence dropped sharply in the next few years, reaching 1.5% by 1991, where it remained through 1993.