Epidemiology is the science of identifying trends and patterns in the occurrence of health problems. Epidemiological studies advance NIDA's mission by gauging the scope and nature of the Nation's drug problems and providing information fundamental to improving treatment and prevention.
NIDA sponsors two major epidemiological tracking programs. The Monitoring the Future study (MTF), now in its 25th year, asks 50,000 students in a representative sample of the Nation's middle and high schools to report on their use of drugs and attitudes toward drug use. MTF provides a sensitive register of trends and patterns of drug use among youth. The other program, NIDA's Community Epidemiology Work Group (CEWG), has tracked drug abuse in 20 of the Nation's largest cities and the State of Texas for 24 years. CEWG gathers information from State and local law enforcement agencies, survey data, and a variety of public health services. The researchers review data on drug-related deaths and emergency department visits, admissions to drug abuse treatment programs, drug arrests, and drug test results among arrestees. CEWG investigators also conduct focus groups and interviews with community members. CEWG is particularly attuned to the harmful impacts of drug abuse and has given early warning of every emerging major drug trend in recent decades.
NIDA uses MTF and CEWG to document the size of the drug abuse problem, spot trends, pinpoint the groups in the Nation's population that are most in need of prevention and treatment, and assess the effectiveness of interventions. Epidemiological estimates of the number of people abusing a particular drug are also used to set NIDA's research agenda. These estimates may be weighed, along with what is known or suspected about the health and social consequences of abusing the drug and evaluations of technical feasibility, in determining directions for research.
NIDA's epidemiology programs also enable us to respond rapidly to new trends in drug use. This is critical because, when a new drug of abuse comes on the scene, young people tend to hear first about its attractive properties. They also need to hear-and hear quickly-about the drug's health and social consequences in order to quell the trend at an early stage.
Within the past year alone, NIDA has twice mobilized rapid responses to epidemiological evidence of new trends. First, the latest MTF recorded a leveling off of students' overall drug use, but a sharp rise in their use of anabolic-androgenic steroids from 1998 to 1999. The results also showed a decrease in the percentage of 12th graders reporting that they believed these drugs are harmful. NIDA immediately mobilized a campaign to alert parents and potential users that steroids are anything but safe. Steroid abusers are at risk for stunted growth, increased aggression, and (although his is rare) fatal liver disease. Males may experience testicular shrinkage and breast enlargement, while females may experience masculinization and menstrual irregularity. To date, NIDA has spread this message via a Research Report, a Community Drug Alert Bulletin, a fact sheet and press releases,and two eye-catching postcards, see Anabolic Steroids Research Report. In mid-April, NIDA and influential partners from the worlds of sports and medicine held a press conference that drew media attention to the dangers of these drugs and announced the first successful program to prevent steroid abuse among high school athletes (see "NIDA Initiative Targets Increasing Teen Use of Anabolic Steroids,"). One register of the timeliness of this effort is the strong response from the public. More than 1,000 individuals viewed the Web site daily during the first days of its operation.
In a second example of epidemiology findings galvanizing a rapid NIDA response, last winter NIDA mounted a similarly comprehensive public information campaign in response to a CEWG finding that use of MDMA (ecstasy), Rohypnol, ketamine, and other so-called club drugs was increasing. Clearly, drug dealers and the reports of some users had convinced many young people that these drugs offered low-risk pleasure. NIDA's continuing campaign emphasizes case reports of acute side effects including heart attacks, strokes, coma, and death from respiratory depression, as well as research findings of long-term neurotoxicity and memory loss following exposure to some of these drugs.
Public information campaigns are among NIDA's most immediate responses to new trends revealed by MTF and CEWG. For the longer term, epidemiological findings highlight questions for research. Thus, NIDA has joined with a number of institutional partners to earmark $54 million to investigate club drugs. As another recent striking example of epidemiological findings leading to a research response, in the 1990s NIDA studies disclosed that most new heroin use was occurring in suburbia rather than-as previously-in urban centers. In addition, many new users were inhaling rather than injecting the drug, often lulled by beliefs that inhalation would not lead to addiction or exposure to blood-borne diseases such as HIV/AIDS and hepatitis C. To examine these beliefs, NIDA sponsored a study of transition from heroin inhalation to injection. Not only did the results show that transition was often rapid, they also documented very high rates of hepatitis C infection among new injecting drug users. NIDA is now disseminating this information as a deterrent to the myth of safe heroin use.
Drug abuse in the Nation is never static. The availability of new illicit drugs, changing circumstances in our communities, even generational shifts fuel new problems and create new opportunities for interventions. By tracing the complex patterns of drug abuse, MTF and CEWG help to identify where prevention and treatment are most needed and can be most effective. They also provide us the measure of our success in curbing the growth in drug abuse that occurred in the 1990s, and of the challenge still remaining.