Traditionally, the term drug abuse referred to the use of any drug prohibited by law, regardless of whether it was actually harmful or not. This meant that any use of marijuana, for example, even if it occurred only once in a while, would constitute abuse, while the same level of alcohol consumption would not. In 1973 the National Commission on Marihuana and Drug Abuse declared that this definition was illogical. The term abuse, the commission stated, "has no functional utility and has become no more than an arbitrary code word for that drug presently considered wrong." As a result, this definition fell into disuse.
The term drug is commonly associated with substances that may be purchased legally by prescription for medical use, such as penicillin, which is almost never abused, and Valium, which is frequently abused, or illegal substances, such as angel dust, which are taken for the purpose of getting high, or intoxicated, but actually have no medical use. Other substances that may be purchased legally and are commonly abused include alcohol (see alcoholism) and nicotine, contained in tobacco cigarettes. In addition, in recent years, chemists working in illegal, clandestine laboratories have developed new chemicals that have been used for the purpose of getting high. (These are called "designer drugs".) All of these substances are psychoactive. Such substancesÑlegal and illegalÑinfluence or alter the workings of the mind; they affect moods, emotions, feelings, and thinking processes.
Drug Dependence
Drug abuse must be distinguished from drug dependence. Drug dependence, formerly called drug addiction, is defined by three basic characteristics. First, users