1. Introduction

This report presents findings from the 2002, 2003, and 2004 National Surveys on Drug Use and Health (NSDUHs) on the nonmedical use of prescription-type psychotherapeutic drugs. NSDUH, an annual survey of the civilian, noninstitutionalized population of the United States aged 12 or older, covers four broad classes of prescription psychotherapeutic drugs: pain relievers, tranquilizers, stimulants, and sedatives. Attention also is given to two specific drugs within these general classes: methamphetamine, a stimulant, and OxyContin^®, a pain reliever. Nonmedical use is defined in NSDUH as use of these medications without a prescription of the respondent's own or simply for the experience or feeling the drug caused. Thus, nonmedical use does not include legitimate use of prescription drugs under a physician's direction, nor does it include use of over-the-counter medications.

1.1. Background

This is a time of widespread concern about the nonmedical use of prescription drugs in the United States. The 2006 National Drug Control Strategy issued by the White House Office of National Drug Control Policy (ONDCP, 2006) identified the illegal use of pharmaceuticals as one of the fastest-growing forms of drug abuse and outlined a program to reduce the availability of such drugs for nonmedical use and get users into treatment. The U.S. Department of Justice's National Drug Threat Assessment for 2006 indicated that

Pharmaceutical drug availability and abuse are at very high levels throughout most of the country. Availability is increasing, continuing a trend that has been developing since the late 1990s; abuse has stabilized at high levels. High availability levels enable individual users to easily and inexpensively acquire drugs, primarily through theft, forged prescriptions, doctor shopping, and the fraudulent practices of some unscrupulous physicians and pharmacists. (National Drug Intelligence Center [NDIC], 2006, p. 23)

The director of the National Institute on Drug Abuse (NIDA) has described the misuse and abuse of prescription medications, particularly opioid analgesics, as a growing public health concern and has called for further research to develop safe and effective pain management strategies and medications with less potential for abuse (Compton & Volkow, 2006; Volkow, 2005).

This is the first NSDUH analytic report that has focused solely on the misuse of prescription drugs. NSDUH's large, representative sample of the population aged 12 or older (more than 200,000 respondents in 2002, 2003, and 2004 combined), its inclusion of measures of the nonmedical use of prescription psychotherapeutic drugs as well as illicit drugs, and its great variety of additional data items make the survey a unique source of data to address the issue of prescription drug misuse. NSDUH provides estimates that are representative at both the national level and within each State. It has sufficient sample size to examine the prevalence of rare drug use patterns, to study trends from 2002 to 2004, and to investigate differences in prevalence and other indicators across demographic groups, socioeconomic circumstances, and geographic areas. In addition to prevalence and incidence of use, the survey provides estimates of dependence on, abuse of, and treatment for the target drugs.

1.2. Results from Other Studies

Information from several national sources suggests that the prevalence of the nonmedical use of prescription psychotherapeutic drugs in the United States has increased notably since the 1990s (Community Epidemiology Work Group [CEWG], 2004; NIDA, 2005). Trend data from the Drug Abuse Warning Network (DAWN) indicate that emergency department (ED) visits involving specific prescription pain relievers and tranquilizers increased significantly from 1995 to 2002 (CEWG, 2004).

Data from the Substance Abuse and Mental Health Services Administration's (SAMHSA's) Treatment Episode Data Set (TEDS) indicate that the numbers and proportions of treatment admissions for primary abuse problems with methamphetamine, amphetamines, and opiates other than heroin increased notably between 1993 and 2003 (Office of Applied Studies [OAS], 2005b).

Monitoring the Future (MTF), a school survey of 8^th, 10^th, and 12^th graders, indicated that nonmedical use of some prescription drugs continued to show relatively high rates or long-term increases in 2005 among youths, in contrast to overall trends that showed a continuing general decline in drug use. For example, 9.5 percent of 12^th graders in 2005 reported using Vicodin^® in the past year, and 5.5 percent of students in this grade reported using OxyContin^® in the past year (Johnston, O'Malley, Bachman, & Schulenberg, 2005). This rate of nonmedical OxyContin^® use in 2005 among 12^th graders was significantly higher than the 4.0 percent of 12^th graders who used this drug nonmedically in the past year in 2002. In addition, the nonmedical use of sedatives in the past year among 12^th graders in 2005 was the highest since 1991.

1.3. Background on Prescription Drug Distribution and Control

In the United States, the manufacture, importation, and distribution of pharmaceutical drugs is subject to Federal regulation. The Food and Drug Administration (FDA), a part of the U.S. Department of Health and Human Services (DHHS), is responsible for certifying the safety and efficacy of new medications and monitoring the safety of pharmaceuticals already on the market.

Pharmaceuticals controlled by the FDA are designated either as over-the-counter drugs or prescription drugs depending on their level of safety and potential for causing adverse effects. Over-the-counter drugs are available without a physician's prescription but are subject to usage guidelines stated on the label, which must be approved by the FDA. Prescription drugs are given that name because they are available only with a prescription from a physician, who is responsible for ensuring that the recipient has a legitimate need for the medication, that the dosage and other specified aspects of usage are appropriate for the patient and his or her condition, that the patient understands the directions for use, that any possible problems with usage are recognized and dealt with, and that usage is monitored in a manner consistent with the level of safety and potential adverse effects of the medication.

The FDA evaluates safety and efficacy prior to approving a drug for distribution and medical use and monitors the occurrence of serious adverse events related to use of the drug once it is on the market. Health care providers (e.g., physicians, pharmacists, nurses) are required to report to a designated Federal adverse event monitoring system any severe adverse effect that is potentially associated with a drug. Any death that is deemed to be potentially related to a drug also is required to be reported. All drugs are subject to revocation of FDA approval or legal action to withdraw the drug from the market.

One of the issues that FDA regulators must address is the potential of medications to produce patterns of dependence or nondependent abuse, a characteristic referred to as "abuse potential." Drugs with abuse potential, which fall mainly into the category of psychoactive or psychotherapeutic substances, are subject to further regulation by the Drug Enforcement Administration (DEA, a part of the U.S. Department of Justice) under the Controlled Substances Act (CSA), which is Title II of the Comprehensive Drug Abuse Prevention and Control Act of 1970. These regulated drugs include both illegal substances (referred to as "street drugs") and the pharmaceuticals subject to FDA regulation. The CSA separates drugs into five categories, known as schedules, depending on their abuse potential, utility in medical treatment, and safety when used under medical supervision:

Schedule I, the most restrictive level, includes drugs or other substances with a high potential for abuse, no currently accepted medical use in the United States, and a low level of safety. Drugs and other substances in Schedule I are not approved for use, distribution, manufacture, or importation. Examples of drugs in Schedule I include heroin, marijuana, phencyclidine (PCP), and lysergic acid diethylamide (LSD). Methaqualone, which has been a Schedule I drug since 1984, had been approved by the FDA in 1965 for use as a sedative and was marketed under the name Quaalude^®. Adverse effects from methaqualone use resulted in DEA rescheduling and FDA action to withdraw it from the market.
Schedule II drugs have high abuse potential but have currently accepted medical use in treatment, though with severe restrictions. Examples of drugs in this category include cocaine, methamphetamine, amphetamines (e.g., dextroamphetamine, Adderall^®), morphine, oxycodone (e.g., OxyContin^®), and methylphenidate (e.g., Ritalin^®).
Schedule III drugs have abuse potential less than that of Schedule I or II drugs and have currently accepted medical uses in treatment. Some drugs in this category include hydrocodone (e.g., Vicodin^®) and butalbital (e.g., Fiorinal^®).
Schedule IV drugs have lower abuse potential than those in Schedule III and currently have accepted medical uses in treatment. Schedule IV includes such drugs as alprazolam (Xanax^®), diazepam (Valium^®), and propoxyphene (e.g., Darvon^®).
Schedule V drugs have low abuse potential and recognized medical uses. Some Schedule V pharmaceuticals contain drugs with higher abuse potential but in much lower concentrations relative to other ingredients. Examples include cough medicines with codeine (e.g., Robitussin AC^®).

The majority of the pharmaceuticals that the FDA has approved for marketing in the United States are not on the CSA schedules, including most prescription drugs and all over-the-counter drugs. The NSDUH questionnaire includes some prescription psychotherapeutic drugs that are not on the CSA schedule, such as tramadol (Ultram^®) and cyclobenzaprine (Flexeril^®).

The usual distribution network for prescription pharmaceuticals involves manufacture under FDA approval, delivery to wholesalers, and dissemination to local pharmacies and hospitals to be dispensed to patients who have prescriptions from physicians. Distribution is subject to a number of administrative controls, and tightness of these controls increases the lower they are on the CSA schedule. CSA forbids distribution of Schedule I drugs and imposes a number of limits on the distribution of drugs in Schedules II and III, including monitoring of physician prescribing practices.

In the context of this report, pharmaceuticals that are misused may have been manufactured by the usual companies but stolen in shipping or at other points in distribution. They are said to have been diverted and ultimately wind up in illicit trafficking. The drugs also may be obtained inappropriately from legitimate end users. In many cases, misused psychotherapeutic drugs are acquired using prescriptions obtained from physicians who are lenient in prescribing controlled substances. In addition, medication prescribing pads may be stolen from physicians' offices and used to write fraudulent prescriptions for psychotherapeutic drugs.

A particular issue with regard to manufacturing and distribution involves methamphetamine, which began many years ago as a prescription drug. In more recent years, methamphetamine for nonmedical use has been manufactured outside the legitimate pharmaceutical industry by illicit laboratories and distributed through illegal trafficking. With the assignment of methamphetamine (e.g., Desoxyn^®) to DEA Schedule II, legitimate prescribing of methamphetamine is rare. It might be said that methamphetamine has moved from being a prescription drug to being principally a street drug. NSDUH and other epidemiological surveys have continued to collect data on methamphetamine use under the rubric of nonmedical use of prescription drugs. For information on future changes to NSDUH that will recognize methamphetamine's role as a street drug, refer to Chapter 8.

1.4. Description of NSDUH

NSDUH is the primary source of statistical information on the use of illegal drugs by the U.S. civilian, noninstitutionalized population aged 12 or older. Conducted by the Federal Government since 1971, the survey collects data by administering questionnaires to a representative sample of the population through face-to-face interviews at their places of residence. The survey, which has been repeated annually since 1990, is sponsored by SAMHSA, an operating division of the DHHS, and is planned and managed by SAMHSA's OAS. Data collection is conducted under contract with RTI International, Research Triangle Park, North Carolina.¹ This section briefly describes the survey methodology; a more complete description is provided in Appendices A and B.

Prior to 2002, the survey was called the National Household Survey on Drug Abuse (NHSDA). Because of improvements to the survey in 2002, the 2002 data constitute a new baseline for tracking trends in substance use and other measures. For this reason, findings in this report are based on data only from the 2002, 2003, and 2004 NSDUHs. Estimates from these 3 survey years should not be compared with estimates from the 2001 or earlier versions of the survey to examine changes in the nonmedical use of prescription psychotherapeutic drugs over time.

Particular strengths of the NSDUH data for reporting on prescription drug abuse in the United States include, but are not limited to, the probability sampling design and large sample sizes (see below). Data are weighted to allow inferences to be made for the civilian, noninstitutionalized population aged 12 or older in the United States and for specific demographic and geographic subgroups within the United States. Large sample sizes and probability sampling yielding representative estimates in each of the 50 States and the District of Columbia ensure coverage of even relatively rare behaviors and provide a high level of precision in the national estimates, particularly when survey data are pooled across multiple years.

NSDUH collects information from residents of households, noninstitutional group quarters (e.g., shelters, rooming houses, dormitories), and civilians living on military bases. The survey does not include homeless persons who do not use shelters, military personnel on active duty, and residents of institutional group quarters, such as jails and hospitals.

Since 1999, the NSDUH interview has been carried out using computer-assisted interviewing (CAI). Most of the questions are administered with audio computer-assisted self-interviewing (ACASI). ACASI is designed to provide the respondent with a highly private and confidential means of responding to questions to increase the level of honest reporting of illicit drug use and other sensitive behaviors. Less sensitive items are administered by interviewers using computer-assisted personal interviewing (CAPI). Overall, approximately 61 percent of the time that respondents spend answering questions is for items administered by ACASI.

The 2002, 2003, and 2004 NSDUHs employed a 50-State sample design with an independent, multistage area probability sample for each of the 50 States and the District of Columbia. The eight States with the largest population (California, Florida, Illinois, Michigan, New York, Ohio, Pennsylvania, and Texas), which together account for 48 percent of the total U.S. population aged 12 or older) were designated as large sample States. For these States, the design provided an annual sample sufficient to support direct State estimates. For the remaining 42 States and the District of Columbia, smaller, but adequate, samples were selected to support State estimates using small area estimation (SAE) techniques. In this report, State variations are studied using conventional direct, weighted, design-based estimates from the sample. For these estimates, 3 years of data (2002, 2003, and 2004) were combined to obtain sample sizes sufficient to produce State estimates that met the precision criteria for publication (see Appendices A and B). The NSDUH design also oversampled youths and young adults, so that each State's sample was approximately equally distributed among three major age groups: 12 to 17 years, 18 to 25 years, and 26 years or older.

Each year's survey was conducted from January through December of that calendar year (e.g., January through December 2004 for the 2004 NSDUH). Sampled dwelling units were screened to identify eligible residents aged 12 or older. Up to two persons per dwelling unit were selected to be interviewed. In each year, respondents were given an incentive payment of $30 for completing the interview.

Weighted response rates for household screening ranged from 90.7 to 90.9 percent for these 3 survey years. Weighted response rates for interviewing ranged from 77.0 to 78.9 percent. Sample sizes were 68,126 in 2002, 67,784 in 2003, and 67,760 in 2004, for a total of 203,670 completed interviews across the 3 years.

1.5. Measurement of Nonmedical Prescription Drug Use in NSDUH

NSDUH collects extensive information on the nonmedical use of prescription-type pain relievers, tranquilizers, stimulants, and sedatives. Nonmedical use, or "misuse," is defined as use of these medications without a prescription of the respondent's own or simply for the experience or feeling the drug caused. Over-the-counter medications are not included.

This definition of nonmedical use casts a wide net. On the extreme end, it covers clear cases of use without medical necessity, which may be frequent and may lead to dependence or abuse. Whether the drugs are acquired using legitimate prescriptions, from illicit traffickers, or by some other means, the individual's intent in these cases would be considered use simply for the experience or feeling the drug causes.

On the other end of the spectrum, the definition includes persons who (1) have an actual medical need for a certain class of drug but do not have a prescription for it, and (2) are given a dose or two of a drug in that class by a friend or family member who has a legitimate prescription. This situation would be considered use without a prescription of the individual's own and would trigger a positive response to the item in the NSDUH prescription drug module, although the individual would not be using the drug simply for the experience or feeling it caused. Despite potential questions about whether users in this latter category are really misusing the drug, these individuals are not likely to have been evaluated by a physician prior to taking the drug. A medical evaluation would take into account a person's particular characteristics and condition to determine the legitimacy of his or her need for medication, the appropriateness of the drug selection, and the appropriate dosage. For further discussion of issues of this type, see Chapter 8.

The survey includes questions that allow for estimation of nonmedical use of pain relievers, tranquilizers, stimulants, and sedatives in the lifetime, past year, and past month periods. Using the data collected for these four drug classes, estimates also are created for nonmedical use of any prescription psychotherapeutic drug in the three time periods mentioned above. In addition, measures of the prevalence of nonmedical use of the stimulant methamphetamine are available for 2002 through 2004. Measures of the past month and past year nonmedical use of the prescription pain reliever OxyContin^® were added to the survey in 2004; in 2002 and 2003, the only data collected about OxyContin^® was lifetime nonmedical use. Incidence estimates for each of these drug categories are produced using responses to questions on age at first use, which are combined with the date of the interview and respondent's date of birth to identify respondents who initiated use in the 12 months prior to the interview and in specific prior calendar years.

NSDUH also contains detailed questions about the nonmedical use of a large set of specific medications. Except for OxyContin^® (a pain reliever) and methamphetamine (a stimulant), however, information collected about specific drugs within the broad psychotherapeutic classes generally is limited to use at any time in the individual's life.

To aid respondents in identification and recall, they are shown "pill cards" displaying the names and color photographs of drugs and groups of drugs in a given therapeutic class. Entries on the cards include brand-name drugs, generic drugs, and some groupings of drugs from different generic categories (see the listings of drugs in Chapter 3 and Appendix B). The selection of specific pharmaceuticals to be shown and their position on the pill cards were based on their prevalence as reported in prior surveys and on recommendations from the FDA, the DEA, and NIDA. Respondents also may specify nonmedical use of other medications as "some other drug" that they have used. These "OTHER, Specify" reports are used in logical editing of the NSDUH data and in the creation of some of the variables measuring nonmedical use.

NSDUH also includes questions about some drugs that previously had been approved for medical use by prescription but currently are not approved by the FDA for marketing in the United States (e.g., generic methaqualone or Quaalude^®). Nevertheless, these drugs may still be available on the illicit drug market, whether produced illegally in this country or smuggled from other countries. These drugs also may have been used nonmedically in the past and thus appear in estimates of lifetime use.

Because nonmedical use of individual prescription-type psychotherapeutic drugs (except for OxyContin^® and methamphetamine) is reported only for the lifetime, a limitation of the data is that it is difficult to make inferences about which specific drugs currently are being misused. Various strategies can be devised to deal with this limitation, each with its own advantages and disadvantages. These advantages and disadvantages are discussed in greater detail in specific chapters and in Appendix B.

1.6. Measures of Demographic and Geographic Characteristics

Data are presented for racial/ethnic groups in several categorizations, based on current standards for collecting and reporting race and ethnicity data (Office of Management and Budget [OMB], 1997) and on the level of detail permitted by the sample. Because respondents were allowed to choose more than one racial group, a "two or more races" category is presented that includes persons who reported more than one category among the seven basic groups listed in the survey question (white, black/African American, American Indian or Alaska Native, Native Hawaiian, Other Pacific Islander, Asian, Other). It should be noted that, except for the "Hispanic or Latino" group, the racial/ethnic groups discussed in this report include only non-Hispanics. The category "Hispanic or Latino" includes Hispanics of any race. Also, more detailed categories describing specific subgroups were obtained from survey respondents if they reported either Asian race or Hispanic ethnicity. Data on Native Hawaiians and Other Pacific Islanders are combined in this report.

Data also are presented for four U.S. geographic regions and nine geographic divisions within these regions. These regions and divisions, defined by the U.S. Census Bureau, consist of the following groups of States:

Northeast Region - New England Division: Connecticut, Maine, Massachusetts, New Hampshire, Rhode Island, Vermont; Middle Atlantic Division: New Jersey, New York, Pennsylvania.

Midwest Region - East North Central Division: Illinois, Indiana, Michigan, Ohio, Wisconsin; West North Central Division: Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota.

South Region - South Atlantic Division: Delaware, District of Columbia, Florida, Georgia, Maryland, North Carolina, South Carolina, Virginia, West Virginia; East South Central Division: Alabama, Kentucky, Mississippi, Tennessee; West South Central Division: Arkansas, Louisiana, Oklahoma, Texas.

West Region - Mountain Division: Arizona, Colorado, Idaho, Montana, Nevada, New Mexico, Utah, Wyoming; Pacific Division: Alaska, California, Hawaii, Oregon, Washington.

Geographic comparisons for 2003 and 2004 also are made based on county type, which reflects different levels of urbanicity and metropolitan area inclusion of counties, based on metropolitan area definitions issued by the OMB in June 2003 (OMB, 2003). For this purpose, counties are grouped based on the 2003 rural-urban continuum codes. These codes were originally developed by the U.S. Department of Agriculture (Butler & Beale, 1994). Each county is either inside or outside a metropolitan statistical area (MSA), as defined by the OMB.

Large metropolitan areas have a population of 1 million or more. Small metropolitan areas have a population of fewer than 1 million. Small metropolitan areas are further classified based on whether they have a population of 250,000 or more. Nonmetropolitan areas are areas outside MSAs. Counties in nonmetropolitan areas are further classified based on the number of people in the county who live in an urbanized area, as defined by the U.S. Census Bureau at the subcounty level. "Urbanized" counties have 20,000 or more population in urbanized areas, "less urbanized" counties have at least 2,500 but fewer than 20,000 population in urbanized areas, and "completely rural" counties have fewer than 2,500 population in urbanized areas.

1.7. Organization of This Report

This report contains separate chapters that discuss the following topics related to the nonmedical use of prescription psychotherapeutic drugs: prevalence and recent trends in the misuse of broad categories of prescription drugs (Chapter 2); patterns in the nonmedical use of specific prescription drugs (Chapter 3); incidence and age at initiation of nonmedical use (Chapter 4); prescription drug misuse and use of other drugs, alcohol, and tobacco (Chapter 5); dependence on or abuse of prescription drugs and receipt of treatment for prescription drug misuse (Chapter 6); and State variations in nonmedical prescription drug use, dependence or abuse, and treatment (Chapter 7). A final chapter (Chapter 8) summarizes the results and discusses key findings in relation to other research and survey results. Technical appendices describe the surveys (Appendix A) and statistical methods and measurement (Appendix B). Appendix C presents tables of estimates for earlier years, and Appendix D contains the tables of estimates referenced in Chapters 2 through 7.

Tables, text, and figures present prevalence measures for the population in terms of both the number of substance users and the rate of use for prescription drugs. Where applicable, similar measures also are presented for illicit drugs, alcohol, and tobacco products. Most estimates presented in this report are based on averages for 2002, 2003, and 2004; combining data from these 3 survey years increases the sample sizes to support detailed estimates. A more limited number of tables and figures show trend data comparing single-year estimates between 2002, 2003, and 2004. In these tables and figures showing trend data, significant differences between survey years are indicated.

¹ RTI International is a trade name of Research Triangle Institute.