and alcohol," as the case may be. Additionally, the words opiate and opioid are used interchangeably, although opiates are derivative of morphine and opioids are all compounds with morphine-like properties (they may be synthetic and not resemble morphine chemically).

The report employs the standard three-stage conceptualization of drug-taking behavior that applies to all psychoactive drugs, whether licit or illicit. Each stage—use, abuse, dependence—is marked by higher levels of use and increasingly serious consequences. Thus, when the report refers to the "use" of drugs, the term is usually employed in a narrow sense to distinguish it from intensified patterns of use. Conversely, the term "abuse" is used to refer to any harmful use, irrespective of whether the behavior constitutes a "disorder'' in the DSM-IV diagnostic nomenclature (see Appendix C). When the intent is to emphasize the clinical categories of abuse and dependence, that is made clear.

The committee also draws a clear distinction between patterns of drug-taking behavior, however described, and the harmful consequences of that behavior for the individual and for society. These consequences include the direct, acute effects of drug taking such as a drug-induced toxic psychosis or impaired driving, the effects of repeated drug taking on the user's health and social functioning, and the effects of drug-seeking behavior on the individual and society. It bears emphasizing that adverse consequences can be associated with patterns of drug use that do not amount to abuse or dependence in a clinical sense, although the focus of this report and the committee's recommendations is on the more intensified patterns of use (i.e., abuse and dependence) since they cause the majority of the serious consequences.

Drug use may be defined as occasional use strongly influenced by environmental factors. Drug use is not a medical disorder and is not listed as such in either of the two most important diagnostic manuals—the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSMIV; APA, 1994); or the International Classification of Diseases (ICD-10; WHO, 1992). (See Appendix C for DSM-IV and ICD-10 diagnostic criteria.) Drug use implies intake for nonmedical purposes; it may or may not be accompanied by clinically significant impairment or distress on a given occasion.

Drug abuse is characterized in DSM-IV as including regular, sporadic, or intensive use of higher doses of drugs leading to social, legal, or interpersonal problems. Like DSM-IV, ICD-10 identifies a nondependent but problematic syndrome of drug use but calls it "harmful use" instead