Single and multiple drug opiate users: addicts or nonaddicts?

ATTENTION has been increasingly focused on the users of multiple drugs by drug abuse researchers. Several authors have stated that, viewed in long-term trends, the single drug user is being replaced by a multiple drug user whose intake might include heroin, amphetamines, barbiturates, and psychedelics-either in combination or on successive occurrences (1-4). The question of multiple drug use becomes more complicated if the multiple drug users are, in fact, addicted to the drug or drugs they are taking. In a 1966 study in New York City, Abeles and co-workers noted that multiple drug use was increasing and that many persons were addicted to opiates and barbiturates (3). The problem of multiple drug use is exacerbated because treatment for withdrawal from one type of drug, such as heroin, may lead to the neglect of withdrawal stress from another type of drug, for example, barbiturates. As Abeles and co-workers pointed out, if one neglects the withdrawal symptoms caused by barbiturates, the patient may suffer serious convulsions which can result in death (3). Freedman also noted that many of today's addicts are multiple drug users. He contends that a decade ago the addict was generally using only