Chapter 2. Illicit Drug Use
The NHSDA obtains information on nine different categories of illicit drug use: marijuana, cocaine, heroin, hallucinogens and inhalants and nonmedical use of prescription-type pain relievers, tranquilizers, stimulants, and sedatives. In these categories, hashish is included with marijuana; and crack is considered a form of cocaine. Several drugs are grouped under the hallucinogens category, including LSD, PCP, peyote, mescaline, mushrooms, and ecstasy (MDMA). Inhalants include a variety of substances such as amyl nitrite, cleaning fluids, gasoline, paint and glue. The four categories of prescription-type drugs (pain relievers, tranquilizers, stimulants, and sedatives) cover numerous drugs available through prescriptions and sometimes illegally "on the street." Methamphetamine is included under stimulants. Over-the-counter drugs and legitimate uses under a doctor's prescription are not included. Respondents are asked to report only uses of drugs not prescribed for them or that they took only for the experience or feeling they caused. NHSDA reports combine the four prescription-type drug groups into a category referred to as "Any psychotherapeutics."
Estimates of "any illicit drug" use reported from the NHSDA reflect use of any of the nine substance categories listed above. Use of alcohol and tobacco products, while illegal for youths, are not included in these estimates, but are discussed in Chapters 3 and 4. Findings from the 2000 NHSDA on illicit drug use are summarized below.
- In 2000, an estimated 14.0 million Americans were current illicit drug users, meaning they had used an illicit drug during the month prior to interview. This estimate represents 6.3 percent of the population 12 years old and older.
- Marijuana is the most commonly used illicit drug. It is used by 76 percent of current illicit drug users. Approximately 59 percent of current illicit drug users consumed only marijuana, 17 percent used marijuana and another illicit drug, and the remaining 24 percent used an illicit drug but not marijuana in the past month. Therefore, about 41 percent of current illicit drug users in 2000 (an estimated 5.7 million Americans) use illicit drugs other than marijuana and hashish, with or without using marijuana as well (Figure 2.1).
- Of the 5.7 million users of illicit drugs other than marijuana, 3.8 million were using psychotherapeutics nonmedically. This represents 1.7 percent of the population aged 12 and older, about the same rate as in 1999 (1.8 percent). Psychotherapeutics include pain relievers (2.8 million users), tranquilizers (1.0 million users), stimulants (0.8 million users), and sedatives (0.2 million users).
- The percentage of the population using illicit drugs did not change from 1999 to 2000 (6.3 percent in both years). There were no statistically significant changes in the overall rates of current use of any of the major illicit drug categories tracked by the survey (Figure 2.2).
- In 2000, an estimated 1.2 million Americans were current cocaine users. This represents 0.5 percent of the population aged 12 and older. The estimated number of current crack users in 2000 is 265,000.
- In 2000, an estimated 1 million Americans were current users of hallucinogens. This number represents 0.4 percent of the population aged 12 and older.
- In 2000, an estimated 6.4 million persons had tried ecstasy at least once in their lifetime. This is more than the estimated 5.1 million lifetime users in 1999. The 2000 NHSDA was not designed to report past month or past year use of ecstasy.
- In 2000, an estimated 130,000 Americans were current heroin users. This represents 0.1 percent of the population aged 12 and older.
- Rates and patterns of drug use show substantial variation by age. For example, 3.0 percent of youths aged 12 and 13 reported current illicit drug use in 2000. Among youth, rates increase with age, peaking in the age group 18 to 20 years (19.6 percent). Beyond age 20, the rates generally decline with increasing age. Adults age 40 to 44 years were an exception to this pattern in both 1999 and 2000, with rates higher than the 35 to 39 year old age group. Members of this cohort in their early forties in 2000 were teenagers during the 1970s, the period when drug use incidence and prevalence rates were rising dramatically. Rates declined consistently in age groups older than age 44, but were still above 2 percent for adults in their fifties (Figure 2.3).
- Among youth aged 12 to 17, 9.7 percent had used an illicit drug within the 30 days prior to interview in 2000. This rate is about the same as the rate for youth in 1999 (9.8 percent).
- Among youth aged 12 and 13, the rate of past month illicit drug use declined from 3.9 percent in 1999 to 3.0 percent in 2000. This was primarily due to a significant drop in inhalant use (from 1.3 percent to 0.7 percent). Marijuana use in this age group was lower in 2000 than in 1999, but this change is not statistically significant (Figure 2.4).
- There were no changes between 1999 and 2000 in rates of use for any of the illicit drug categories for youths aged 14 and 15 (Figure 2.5).
- Use of psychotherapeutics nonmedically increased among youths aged 16 and 17 between 1999 and 2000, from 3.4 percent to 4.3 percent. The increase was observed for pain relievers as well as stimulants (particularly methamphetamine). Overall illicit drug use among youths aged 16 and 17 was higher in 2000 than in 1999, but the change did not reach statistical significance (Figure 2.6).
- There were few changes in rates of drug use among adult age groups (18 to 25 years and 26 years and older) between 1999 and 2000 (Figures 2.7 and 2.8). Among young adults aged 18 to 25, past month use of crack declined from 0.3 percent to 0.1 percent, and stimulant use declined from 1.1 percent to 0.8 percent. These declines occurred among those aged 21 to 25, but not among those aged 18 to 20. There were no changes in rates for older adults aged 26 and older, although a decline in crack use and increases in hallucinogen and nonmedical pain reliever use were observed among adults age 26 to 34 years.
- While rates of use of most drugs in 2000 were higher among youth and young adults than among older adults, the age distribution of users varied considerably by type of drug. Overall, about half (49 percent) of current illicit drug users were under age 26. However, 83 percent of hallucinogen users and 62 percent of inhalant users were under age 26 in 2000. Conversely, only 32 percent of heroin users, 43 percent of cocaine users and 45 percent of nonmedical psychotherapeutic users were under age 26.
- Approximately 2.1 million youths aged 12 to 17 had used inhalants at some time in their lives as of 2000. This constituted 8.9 percent of youths. Of youth, 3.9 percent had used glue, shoe polish, or Toluene, and 3.3 percent had used gasoline or lighter fluid.
- As in prior years, men continued to have a higher rate of current illicit drug use than women (7.7 percent vs. 5.0 percent) in 2000. However, the rates of nonmedical psychotherapeutic use were similar for males (1.8 percent) and females (1.7 percent).
- Between 1999 and 2000, the rate of past month marijuana use among women aged 12 and older increased from 3.1 percent to 3.5 percent. This was primarily due to an increase in use among women aged 26 and older, from 1.4 percent in 1999 to 2.0 percent in 2000.
- Among youths aged 12 to17 in 2000, the rate of current illicit drug use was similar for boys (9.8 percent) and girls (9.5 percent). While boys aged 12 to 17 had a slightly higher rate of marijuana use than girls (7.7 percent compared to 6.6 percent), girls were somewhat more likely to use psychotherapeutics nonmedically than boys (3.3 percent compared to 2.7 percent) (Figure 2.9).
- Between 1999 and 2000, there was no significant change in the rate of current illicit drug use for either males or females aged 12 to 17 years.
- Among pregnant women aged 15 to 44 years, 3.3 percent reported using illicit drugs in the month prior to interview (based on the combined 1999 and 2000 NHSDA samples). This rate is significantly lower than the rate among non-pregnant women aged 15 to 44 years (7.7 percent). Among pregnant women aged 15 to 17 years, the rate of use was 12.9 percent, nearly equal to the rate for non-pregnant women of the same age (13.5
percent) Figure 2.10).
- In 2000, the rate of current illicit drug use was higher among black pregnant women (7.1 percent) than among white (2.9 percent) or Hispanic (2.1 percent) pregnant women (Figure 2.11).
- The rates of current illicit drug use for major racial/ethnic groups in 2000 were 6.4 percent for whites, 5.3 percent for Hispanics, and 6.4 percent for blacks. The rate was highest among the American Indian/Alaska Native population (12.6 percent) and among persons reporting more than one race (14.8 percent). Asians had the lowest rate (2.7 percent).
- Although Asians as a group had the lowest rate of current illicit drug use, there were variations among the various specific Asian subgroups. For persons aged 12 and older, the rates ranged from 1.0 percent of Chinese and 2.1 percent of Asian Indians to 6.9 percent of Koreans, 5.0 percent of Japanese, and 4.3 percent of Vietnamese. These estimates are based on combined 1999 and 2000 NHSDA data, to ensure adequate sample sizes for these population subgroups (Figure 2.12).
- Based on combined 1999 and 2000 data, rates of past month illicit drug use in the population aged 12 and older were 10.1 percent for Puerto Ricans, 5.5 percent for Mexicans, 4.1 percent for Central or South Americans, and 3.7 percent for Cubans (Figure 2.12).
- Among youths aged 12 to 17 years, the rate of current illicit drug use was highest among American Indian/Alaska Natives (22.2 percent for combined 1999 and 2000 data).
- Illicit drug use rates are correlated with educational status. Among adults aged 18 and older in 2000, college graduates had the lowest rate of current use (4.2 percent). The rate was 6.3 percent among adults who had not completed high school. This is despite the fact that adults who had completed four years of college were more likely to have tried illicit drugs in their lifetime when compared to adults who had not completed high school (44.6 percent vs. 28.9 percent).
- In the college age population (aged 18 to 22 years) the rate of current illicit drug use was nearly the same among full-time undergraduate college students (18.4 percent) as for other persons aged 18 to 22 years, including part-time students, students in other grades, or non-students (18.2 percent). The rate of use was unchanged between 1999 and 2000 for both students and non-students.
- Current employment status is also highly correlated with rates of illicit drug use. An estimated 15.4 percent of unemployed adults (aged 18 and older) were current illicit drug users in 2000, compared with 6.3 percent of full-time employed adults and 7.8 percent of part-time employed adults.
- Although the rate of drug use is higher among unemployed persons than other employment groups, most drug users are employed. Of the 11.8 million adult illicit drug users in 2000, 9.1 million (77 percent) were employed either full time or part time.
- The rate of current illicit drug use in 2000 was 8.0 percent in the West region, 6.6 percent in the Northeast, 5.7 percent in the Midwest region, and 5.5 percent in the South. By geographic division, rates ranged from 10.0 percent in New England and 8.3 percent in the Pacific division to 4.9 percent in the West South Central division and 4.1 percent in the West North Central division. Between 1999 and 2000, the rate in the West North Central Division declined from 5.4 percent to 4.1 percent.
- The rate of illicit drug use in metropolitan areas was higher than the rate in nonmetropolitan areas. Rates were 6.5 percent in large metropolitan areas, 6.7 percent in small metropolitan areas, and 5.1 percent in nonmetropolitan areas. Rural nonmetropolitan counties had lower rates of illicit drug use than other counties. Rates were 3.9 percent in completely rural counties and 4.5 percent in less urbanized nonmetropolitan counties. (Figure 2.13)
- Among youth in 2000, rates of any illicit drug use were similar across county types. Rates ranged from 8.0 percent in less urbanized nonmetropolitan counties to 11.5 percent in urbanized nonmetropolitan counties. The rate of use for youth in large metropolitan areas was 9.4 percent.
Criminal Justice Populations
- In 2000, among the estimated 1.2 million adults on parole or other supervised release from prison during the past year, 21.6 percent had used an illicit drug in the past month. This rate is higher than the rate for adults not on parole or supervised release (5.8 percent) (Figure 2.14).
- Among the estimated 3.7 million adults on probation at some time in the past year, 24.2 percent reported using an illicit drug in the past month in 2000. This compares with a rate of 5.5 percent among adults not on probation (Figure 2.14).
Frequency of Use
- Between 1999 and 2000, the frequency of marijuana use among past year users increased. In 1999, 31.6 percent of past year marijuana users used on 100 or more days in the past 12 months, including 10.2 percent who used on 300 or more days. In 2000, the comparable percentages were 34.7 and 11.7, respectively (Figure 2.15). This occurred among a relatively constant number of past year marijuana users (19.1 million in 1999 and 18.6 million in 2000).
- There was evidence of the shift to more frequent use in each of the three primary age groups (12 to 17, 18 to 25, and 26 and older), although the change was relatively small and not statistically significant among young adults aged 18 to 25.
Association with Cigarette and Alcohol Use
- The rate of past month illicit drug use among both adults and youths was higher among those that were currently using cigarettes or alcohol, compared with adults and youths not using cigarettes or alcohol. In 2000, 4.6 percent of nonsmokers aged 12 to 17 years used illicit drugs, while among youths who used cigarettes, the rate of past month illicit drug use was 42.7 percent. The rate of illicit drug use was also associated with the level of alcohol use. Among youths who were heavy drinkers in 2000, 65.5 percent were also current illicit drug users. Among nondrinkers, only 4.2 percent were current illicit drug users.
Driving Under the Influence of Illicit Drugs
- An estimated 7.0 million persons reported driving under the influence of an illicit drug at some time in the past year. This corresponds to 3.1 percent of the population aged 12 and older, and is significantly lower than the rate in 1999 (3.4 percent). Among young adults aged 18 to 25 years, 10.7 percent drove under the influence of illicit drugs at least once in the past year.
- Of the 7.0 million persons who had driven under the influence of illicit drugs in the past year, most (77 percent) had also driven under the influence of alcohol.
This page was last updated on June 03, 2008.