The Social and Medical Aspects of Drug Abuse

The work of Abraham Wikler (1973) over the past three decades has called attention to the importance of conditioned responses in the addictive process. Drugs act as powerful forces in shaping behavior, both by their direct pleasant effects (positive reinforcement) and by their effects in relieving withdrawal symptoms (negative reinforcement). Wikler theorized that the environmental cues which have been repeatedly paired with drug-induced states may become conditioned stimuli. He observed that former addicts who are free of drugs often develop tearing and yawning (opiate withdrawal signs) when they discuss drugs in group therapy. He and others subsequently showed that withdrawal signs could become conditioned in animals (Wikler and Pescor, 1967; Goldberg and Schuster, 1970). More recently, conditioned withdrawal has been demonstrated in humans (O'Brien et al, 1975; O'Brien et al, 1977). These conditioned withdrawal responses are thought to be partly due to simple pairing of pharmacological withdrawal with environmental cues, and partly due to pairing of environmental stimuli with the body's homeostatic mechanisms adapting to the onset of drug effects (Wikler, 1973; Siegel, 1974). Eventually the environmental stimuli themselves can elicit the adaptative response and this can be perceived as withdrawal. As a result of this conditioning former addicts may develop withdrawal symptoms when they return to the environment in which they had previously used drugs. Not only do they develop drug-craving, but actual physical signs of sickness may occur (tearing, yawning, nausea, vomiting). There is also some evidence (Whitehead, 1974; O'Brien, 1975) that conditioned withdrawal can occur in patients maintained on a steady dose of methadone. There are other conditioning factors which help to maintain self-administration of drugs. Addicts tend to use drugs in a ritualistic fashion. When the drug is administered, the withdrawal discomfort (both pharmacological and conditioned) is eased. At times, depending on the level of tolerance and dose of the drug used, the patient will feel euphoric. There is some controversy over how often a typical addict obtains euphoria rather than just relief of withdrawal distress (McAulliffee and Gordon, 1974), but clearly the reward is intermittant. Since intermittant reinforcement is very effective in maintaining behavior, this may explain why self-administration can continue when street heroin potency is low or when saline is substituted for opiate (O'Brien, 1975). Addicts who report pleasure from self-injection of inactive substances have been termed "needle freaks" (Levine, 1974). This phenomenon is usually seen only in "blind" conditions when the user expects a drug effect, but the substance administered actually contains little or no active drug. If addicts are informed that a substance is a placebo or if they know they are on an antagonist which will block drug effects, self-injection will stop after a few trials (Altman et al, 1976).