the collective costs of drug use and abuse (approximately $257 billion) exceeds the estimated annual $117 billion cost of heart disease and the estimated annual $104 billion cost of cancer (AHA, 1992; ACS, 1993; D. Rice, University of California at San Francisco, personal communication, 1995). The federal government investment in drug abuse research and development (in FY 1995) was $542.2 million, which represents 4 percent of the $13.3 billion spent by the federal government on drug abuse (ONDCP, 1996). By comparison, $8.5 billion (64 percent of the FY 1995 budget) was spent on criminal justice programs; $2.7 billion (20 percent) on treatment of drug abuse, and $1.6 billion (12 percent) on prevention efforts.
The widespread prevalence of illicit drug use in the United States presents another indication of the need for continued research. It was estimated that in 1994, 12.6 million people had used illicit drugs (primarily marijuana) in the past month (SAMHSA, 1995). The number of heavy drug users, using at least once a week, is difficult to determine. It has been estimated that in 1993 there were 2.1 million heavy cocaine users and 444,000 to 600,000 heavy heroin users (Rhodes et al., 1995).
In light of the magnitude of the drug abuse problem in the United States and the adverse health and social consequences, the National Institute on Drug Abuse (NIDA) requested that the Institute of Medicine (IOM) examine accomplishments in drug abuse research and provide guidance for future research. The IOM Committee on Opportunities in Drug Abuse Research (formed in January 1995) is convinced that the field is on the threshold of significant advances, and that a sustained research effort will strengthen society's capacity to reduce drug abuse and ameliorate its adverse consequences. The committee's report focuses broadly on opportunities and priorities for future scientific research in drug abuse.
In the committee's view, the term drug should be understood, in its generic sense, to encompass alcohol and nicotine as well as illicit drugs. It is very important for the general public to recognize that alcohol and nicotine constitute, by far, the nation's two largest drug problems, whether measured in terms of morbidity, mortality, or social cost. Continued separation of alcohol, nicotine, and illicit drugs in everyday speech is an impediment to public education, prevention, and therapeutic progress.
Although the committee uses the term drug in its generic sense, to encompass alcohol and nicotine, the report focuses, at NIDA's request, on research opportunities relating to illicit drugs; research on alcohol and nicotine is discussed only when the scientific inquiries are intertwined. Because the report sometimes ranges more broadly than illicit drugs, how-