Trends in Drug Use - Trends In Prevalence

The prevalence of drug use is tracked by SAMHSA in its National Survey and by the Drug Abuse Warning Network (DAWN), also sponsored by SAMHSA, which collects data from the emergency departments of the nation's hospitals. DAWN also collects drug-related mortality data, as does the National Center for Health Statistics, another element of the U.S. Department of Health and Human Services. Data from these sources are presented here. A discussion of different groupings of drug users (pregnant women, youths, the working population, military people, and persons arrested) is presented in Chapter 4.

The findings of SAMHSA's National Survey will be explored in this section, and the other surveys will be discussed separately below. The National Survey divides illicit drug use responses into three categories: lifetime use, past year use, and current use. Current use is defined as use of a drug within the last month. Data for the 1979 to 2001 period, by age groups, are shown in Table 3.2. Comparing 1979 with 1998 data (the period before the sampling redesign took effect) shows that for all ages and

TABLE 3.2
Illicit drug use, 1979-2001
SOURCE: Adapted from "Table 1. Trends on the Percentage of Persons Reporting Any Illicit Drug Use: 1979-2001," in Drug Use Trends, Fact Sheet, Office of National Drug Control Policy, Executive Office of the President, October 2002

Age of respondent and recency of drug use	1979	1985	1988	1990	1993	1996	1998	Change 1993 to 1998	1999*	2000*	2001*	Change 1999 to 2001
12-17
Ever	31.8%	27.4%	22.8%	20.9%	16.4%	22.1%	21.3%		27.6%	26.9%	28.4%
Past year	24.3	20.7	14.9	14.1	11.9	16.7	16.4		19.8	18.6	20.8
Past 30 days	16.3	13.2	8.1	7.1	5.7	9.0	9.9	4.2	9.8	9.7	10.8	1.0
18-25
Ever	69.0%	62.9%	58.1%	54.9%	50.2%	48.0%	48.1%		52.6%	51.2%	55.6%
Past year	45.5	37.4	29.1	26.1	24.2	26.8	27.4		29.1	27.9	31.9
Past 30 days	38.0	25.3	17.9	15.0	13.6	15.6	16.1	2.5	16.4	15.9	18.8	2.4
26-34
Ever	49.0%	59.5%	61.2%	59.8%	58.2%	53.1%	50.6%		53.2%	50.9%	53.3%
Past year	23.0	26.2	19.1	18.4	14.6	14.6	12.7		13.5	13.4	16.1
Past 30 days	20.8	23.1	14.7	10.9	9.5	8.4	7.0	− 2.5	6.8	7.8	8.8	2.0
35 and older
Ever	11.8%	18.1%	20.0%	22.5%	26.1%	29.0%	31.8%		35.7%	35.5%	38.4%
Past year	3.9	5.5	5.1	5.2	5.5	5.3	5.5		5.9	5.5	6.3
Past 30 days	2.8	3.9	2.3	3.1	3.0	2.9	3.3	0.3	3.4	3.3	3.5	0.1
All ages 12 and older
Ever	31.3%	34.4%	34.0%	34.2%	34.2%	34.8%	35.8%		39.7%	38.9%	41.7%
Past year	17.5	16.3	12.4	11.7	10.3	10.8	10.6		11.5	11.0	12.6
Past 30 days	14.1	12.1	7.7	6.7	5.9	6.1	6.2	0.3	6.2	6.3	7.1	0.8
Note: Any illicit drug use includes use of marijuana, cocaine, hallucinogens, inhalants, heroin, or nonmedical use of sedatives, tranquilizers, stimulants, or analgesics. Prior to 1979, data were not totaled for overall drug use and instead were published by specific drug type only.
*Changes made to the design and execution of National Household Survey of Drug Abuse (NHSDA) in 1999 make the 1999, 2000, and 2001 data incomparable to previous years.
However, 1999, 2000, and 2001 data are comparable to each other.

for any illicit drug, lifetime use of drugs increased from 31.3% of the population in 1979 to nearly 36% in 1998. Past year use dropped from 17.5 to 10.6% of the population, and current use (in the past month) dropped from 14.1% to 6.2% in this period. Results between 1999 and 2001 indicate a change in this pattern: drug prevalence showed an increase in the more recent period—most likely because incidence of drug use went up in the early 1990s and was now beginning to be mirrored in prevalence after a lag in time.

Looking at results for the 1999-2001 period, the biggest increases in current use were among those aged eighteen to twenty-five, up 2.4%, and the next highest increase was among those aged twenty-six to thirty-four, up two percentage points. Respondents aged twelve to seventeen had an increase of 1% between 1999 and 2001, and those aged thirty-five and older the lowest increase, at 0.1%. Looking back at the previous five years (1993 to 1998), the age group leading growth was the youngest, increasing in current use from 5.7 to 9.9%, up 4.2%; next were those aged eighteen to twenty-five, up 2.5% from 13.6% in 1993 to 16.1% in 1998. Those aged twenty-six to thirty-four saw a decline of 2.5 points from 9.5% to 7%. Those in the oldest group registered a small increase of 0.3%.

Figure 3.3 shows current drug use by age group for 2003. Those aged eighteen to twenty reported the highest current illicit drug use, at 23.3%, followed by those in the sixteen to seventeen age range, at 19.2%, and those in the twenty-one to twenty-five range, at 18.3%. Table 3.3 and Table 3.4 show that illicit drug use among persons aged twelve and over continued to increase in 2002 and 2003, both in terms of total number and percentage. In 2003, 46.4% of respondents reported that they had used some illicit drug in their lifetime.

Current use prevalence patterns for "any illicit drug" and for marijuana, cocaine, and heroin are shown in Figure 3.4, with more recent data in percentage terms shown in Figure 3.5. While current use of all drugs generally decreased from 1979 forward, cocaine's prevalence rose after 1979 and reached a peak in 1985, two years after it had reached its "first use" peak. SAMHSA does not claim hard-and-fast correlations between incidence and prevalence, but the agency points out that peaks in prevalence tend to follow peaks in incidence by some two or three years.

In 1979, 25.4 million people aged twelve years and older were using drugs. (See Figure 3.4.) The lowest point was reached in 1992, when current users dropped to twelve million individuals. By 2003, current users had increased substantially again to about 19.5 million. (See Table 3.3.) Expressed as percentages of the total population, these numbers were 14.1% in 1979, 5.8% in 1992, and FIGURE 3.3
Current drug use by age, 2003
SOURCE: "Figure 2.5. Past Month Illicit Drug Use, by Age: 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005) 8.2% in 2003, according to SAMHSA. Current use rises and falls as a percentage of population, but lifetime usage has simply increased over the years. SAMHSA reports that in 1979, 70.2 million people had used drugs in their lifetime (31.3% of the 1979 population). In 2003, more than 110 million people had used a drug sometime in their lives (46.4% of the 2003 population).

Any Illicit Drug

By age group in 2003, eighteen- to twenty-five-year-olds used drugs more than any other age group—in their lifetime, in the past year, and in the past month. (See Table 3.5.) Next came those aged twelve to seventeen in all categories except lifetime. The twenty-six and older age group had the second-highest proportion of lifetime use and the lowest past year and current usage. Males consistently outnumber females among drug users. In lifetime usage, the difference is 9.3 points: 51.2% of males but only 41.9% of females had used drugs in their lifetimes in 2003. Among racial categories, the largest user group was American Indians or Alaska Natives: 62.4% of this group had used drugs in their lifetimes. Those reporting being of more than one race were second (60.1% lifetime use). More whites (49.2%) than African-Americans (44.6%) reported ever having used drugs. For use within the last year, that pattern has now reversed: 14.9% of whites and 15.4% of African-Americans reported use. For current use (within the last month), slightly more African-Americans (8.7%) had used drugs than whites (8.3%). Nearly all of these percentages are higher than they were reported two years earlier by SAMHSA.

Drug-by-Drug

The SAMHSA definition of "any illicit drug" covers quite a variety of substances. In terms of prevalence of current use, the most used drug category in 2003 was marijuana and hashish, which 14.6 million people had used in the previous month. (See Table 3.3.) Nearly 4.7 million people took prescription-type pain relievers in nonmedical applications in the previous month. In 2003 another 1.8 million abused tranquilizers in the past month. (Figure 3.6 outlines the number of lifetime nonmedical users taking various brands of pain relievers in 2002 and 2003.) Current cocaine users numbered nearly 2.3 million in 2003; of those, 604,000 smoked crack cocaine. In both cases, cocaine use was up well over the 2000 levels reported by SAMHSA. Hallucinogens represented the next most frequently used illegal drug, listed as currently used by just over one million people in 2003. Ecstasy accounted for nearly half of those users.

TABLE 3.3
Use of illicit drugs among persons aged 12 or older, by type of drug, 2002 and 2003
[Numbers in thousands]
SOURCE: "Table G.1. Illicit Drug Use in Lifetime, Past Year, and Past Month among Persons Aged 12 or Older: Numbers in Thousands, 2002 and 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005)

	Time period
	Lifetime		Past year		Past month
Drug	2002	2003	2002	2003	2002	2003
Any illicit druga	108,255	110,205	35,132	34,993	19,522	19,470
Marijuana and hashish	94,946	96,611	25,755	25,231	14,584	14,638
Cocaine	33,910	34,891	5,902	5,908	2,020	2,281
Crack	8,402	7,949	1,554	1,406	567	604
Heroin	3,668	3,744	404	314	166	119
Hallucinogens	34,314	34,363	4,749d	3,936	1,196	1,042
LSD	24,516	24,424	999d	558	112	133
PCP	7,418	7,107	235	219	58	56
Ecstasy	10,150	10,904	3,167d	2,119	676c	470
Inhalants	22,870	22,995	2,084	2,075	635	570
Nonmedical use of any psychotherapeuticb	46,558	47,882	14,680	14,986	6,210	6,336
Pain relievers	29,611c	31,207	10,992	11,671	4,377	4,693
Tranquilizers	19,267	20,220	4,849	5,051	1,804	1,830
Stimulants	21,072	20,798	3,181c	2,751	1,218	1,191
Methamphetamine	12,383	12,303	1,541	1,315	597	607
Sedatives	9,960	9,510	981	831	436	294
Any illicit drug other than marijuanaa	70,300	71,128	20,423	20,305	8,777	8,849
aAny illicit drug includes marijuana/hashish, cocaine (including crack), heroin, hallucinogens, inhalants, or any prescription-type psychotherapeutic used nonmedically. Any illicit drugother than marijuana includes cocaine (including crack), heroin, hallucinogens, inhalants, or any prescription-type psychotherapeutic used nonmedically.
bNonmedical use of any prescription-type pain reliever, tranquilizer, stimulant, or sedative; does not include over-the-counter drugs.
cDifference between estimate and 2003 estimate is statistically significant at the 0.05 level.
dDifference between estimate and 2003 estimate is statistically significant at the 0.01 level.

TABLE 3.4
Percentage of illicit drug use among persons aged 12 or older, by type of drug, 2002 and 2003
[Numbers are percentages]
SOURCE: "Table G.2. Illicit Drug Use in Lifetime, Past Year, and Past Month among Persons Aged 12 or Older: Percentages, 2002 and 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005)

	Time period
	Lifetime		Past year		Past month
Drug	2002	2003	2002	2003	2002	2003
Any illicit druga	46.0	46.4	14.9	14.7	8.3	8.2
Marijuana and hashish	40.4	40.6	11.0	10.6	6.2	6.2
Cocaine	14.4	14.7	2.5	2.5	0.9	1.0
Crack	3.6	3.3	0.7	0.6	0.2	0.3
Heroin	1.6	1.6	0.2	0.1	0.1	0.1
Hallucinogens	14.6	14.5	2.0d	1.7	0.5	0.4
LSD	10.4	10.3	0.4d	0.2	0.0	0.1
PCP	3.2	3.0	0.1	0.1	0.0	0.0
Ecstasy	4.3	4.6	1.3d	0.9	0.3c	0.2
Inhalants	9.7	9.7	0.9	0.9	0.3	0.2
Nonmedical use of any psychotherapeuticb	19.8	20.1	6.2	6.3	2.6	2.7
Pain relievers	12.6	13.1	4.7	4.9	1.9	2.0
Tranquilizers	8.2	8.5	2.1	2.1	0.8	0.8
Stimulants	9.0	8.8	1.4c	1.2	0.5	0.5
Methamphetamine	5.3	5.2	0.7	0.6	0.3	0.3
Sedatives	4.2	4.0	0.4	0.3	0.2	0.1
Any illicit drug other than marijuanaa	29.9	29.9	8.7	8.5	3.7	3.7
aAny illicit drug includes marijuana/hashish, cocaine (including crack), heroin, hallucinogens, inhalants, or any prescription-type psychotherapeutic used nonmedically.
bNonmedical use of any prescription-type pain reliever, tranquilizer, stimulant, or sedative; does not include over-the-counter drugs.
cDifference between estimate and 2003 estimate is statistically significant at the 0.05 level.
dDifference between estimate and 2003 estimate is statistically significant at the 0.01 level.

FIGURE 3.4
Estimated number of current users of selected illegal drugs, 1979-2001
SOURCE: Adapted from National Institute on Drug Abuse (1979-1991) and Substance Abuse and Mental Health Services Administration (1992-2001), National Household Survey on Drug Abuse, as reported by the Office of National Drug Control Policy, The White House, http://www.whitehousedrugpolicy.gov/publications/policy/ndcs03/table1.html, and population data from U.S. Census Bureau

Also within that category, 133,000 people used LSD in 2003—up slightly from the previous year—and PCP users remained stable at about 56,000 users. Heroin was currently used by the smallest number of people, 119,000 in 2003, declining from 166,000 users in 2002. In both years, users represented 0.1% of the population, or one in a thousand. (See Table 3.4.)

Marijuana

Marijuana remains the most commonly used illicit substance in the United States. It was used by slightly more than 75% of current illicit drug users—either alone or with another illicit drug in 2003. (See Figure 3.7.) Marijuana is almost always smoked in the form of hand-rolled cigarettes or in pipes. Occasionally it is ingested.

Well over a third of the population twelve or older has used marijuana at least once. (See Table 3.4.) In 2003, 40.6%, or 96.6 million people, had used it at least once in their lifetime. The statistics on marijuana mirror those for "any illicit drug" because marijuana is the most commonly used illegal drug and dominates the survey numbers. Use of the plant has been increasing again. Among current users of any illicit drug, more than 1.6 million more people told SAMHSA in 2003 that they had used marijuana in their lifetime than had done so the year before. (See Table 3.3.) SAMHSA reports that African-Americans and whites used marijuana in similar percentages in the last month, but more whites had smoked pot in their lifetimes than African-Americans. Marijuana was least used by Asians and those of Hispanic origin.

FIGURE 3.5
Current use of selected drugs by persons aged 12 or older, 2002 and 2003
SOURCE: "Figure 2.2. Past Month Use of Selected Illicit Drugs among Persons Aged 12 or Older: 2002 and 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005)

TABLE 3.5
Use of illicit drugs among persons aged 12 and older, by demographic characteristics, 2002 and 2003
[Numbers are percentages]
SOURCE: "Table G.7. Any Illicit Drug Use in Lifetime, Past Year, and Past Month among Persons Aged 12 or Older, by Demographic Characteristics: Percentages, 2002 and 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005)

	Time period
	Lifetime		Past year		Past month
Demographic characteristic	2002	2003	2002	2003	2002	2003
Total	46.0	46.4	14.9	14.7	8.3	8.2
Age
12-17	30.9	30.5	22.2	21.8	11.6	11.2
18-25	59.8	60.5	35.5	34.6	20.2	20.3
26 or older	45.7	46.1	10.4	10.3	5.8	5.6
Gender
Male	50.7	51.2	17.6	17.2	10.3	10.0
Female	41.7	41.9	12.5	12.4	6.4	6.5
Hispanic origin and race
Not Hispanic or Latino	47.0	47.7	14.9	14.7	8.5	8.2
White	48.5	49.2	14.9	14.9	8.5	8.3
Black or African American	43.8	44.6	16.8	15.4	9.7	8.7
American Indian or Alaska Native	58.4	62.4	19.4	18.9	10.1	12.1
Native Hawaiian or other
Pacific Islander	*	51.0	17.0	18.5	7.9	11.1
Asian	25.6	25.6	7.6	7.1	3.5	3.8
Two or more races	54.0	60.1	20.9	20.1	11.4	12.0
Hispanic or Latino	38.9	37.0	15.0	14.7	7.2	8.0
*Low precision; no estimate reported.
Note: Any illicit drug includes marijuana/hashish, cocaine (including crack), heroin, hallucinogens, inhalants, or any prescription-type psychotherapeutic used nonmedically.

Cocaine

Cocaine is usually sniffed or "snorted." The drug enters the body through the mucous membranes of the nose. It can also be injected or smoked, and it is some-times used in conjunction with other drugs. The most popular and notorious combination of cocaine and another illegal drug is the "speedball," a dangerous mixture of heroin and cocaine. Crack is a purified, smokable form of cocaine obtained by chemical processing. Its low prices (generally about $5 to $10 per dose) have made this form of cocaine available to all segments of the American population. According to SAMHSA, about a fifth of all consumers of cocaine in 2003 smoked crack.

The costs of powdered cocaine and the dangers associated with crack have restricted lifetime use of the drug to 14.7% of the population (34.9 million people in 2003). (See Table 3.3 and Table 3.4.) Current users, some 2.3 million individuals, were two-thirds male according to SAMHSA's 2003 survey. Overall, 1% of those surveyed had used cocaine in the previous month. Those eighteen to twenty-five had the highest current usage rate for cocaine.

Heroin

As shown in Table 3.3, in 2003, 119,000 individuals were current users and 3.7 million reported having used heroin at least once in their lifetime. SAMHSA has not provided additional data on heroin users comparable to those shown for other drugs since 1998—in part because data on such users became less reliable using the new sampling techniques. Even before the methodological change, heroin use was underreported, according to SAMHSA, because users, especially current users, are disinclined to talk to surveyors. Data for 1998 indicate (NHSDA 1998, Rockville, MD: SAMHSA, 2000) that a higher percentage of African-Americans had used heroin in their lifetime (1.9%) than whites (1%). Data for use of heroin in the past year was 0.1% of whites and 0.2% of African-Americans. In nearly all other drug categories, a higher percentage of whites used drugs than African-Americans. The highest percentage of current users of heroin were those aged eighteen to twenty-five. Males were 60% of all users.

Hallucinogens, Inhalants, and Psychotherapeutics

About 3.9 million people used hallucinogens in the past year in 2003, down from 4.7 million in 2002. (See Figure 3.8.) Most, according to SAMHSA, were in the youth category dominated by the eighteen- to twenty-five-year segment. American Indians/Alaska Natives generally showed the highest usage measured in percentage, while Asians were usually least involved in use of these drugs.

Lifetime inhalant use leveled off at 9.7% in 2003 (see Table 3.4), after increasing from 7.5% to 8.1% of the FIGURE 3.6
Nonmedical use of pain relievers by persons aged 12 or older, 2002 and 2003
SOURCE: "Figure 2.4. Numbers (in Millions) of Lifetime Nonmedical Users of Selected Pain Relievers among Persons Aged 12 or Older: 2002 and 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005) FIGURE 3.7
Types of drugs currently used by persons aged 12 and over, 2003
SOURCE: "Figure 2.1. Types of Drugs Used by Past Month Illicit Drug Users Aged 12 or Older: 2003," in Results from the 2003 National Survey on Drug Use and Health: National Findings, U.S. Department of Health and Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies, 2004, http://www.oas.samhsa.gov/nhsda/2k3nsduh/2k3ResultsW.pdf (accessed February 10, 2005) population from 2000 to 2001, according to SAMHSA. Whites were more likely to have used inhalants in their lifetimes than African-Americans. The largest percentages were among American Indians/Alaska Natives and those of more than one race. Past year inhalant use also remained stable between 2002 and 2003, at 0.9%. Among those using inhalants currently, the leading age group was the youngest (twelve to seventeen).

In 2003 some 6.3 million individuals had used prescription medicines in the past month for other than medical purposes (see Table 3.3), those in the eighteen to twenty-five age group more predominantly than those younger or older. In this single category of drug use, female participation in current use was nearly the same as the male, according to the 2003 SAMHSA report. For "any illicit drug" in 2003 (current use) females were far less likely than males to participate—6.5%, compared to 10% for males. (See Table 3.5.)