Researchers supported by the National Institute on Drug Abuse (NIDA) have found that craving for nicotine appears to be linked to increased craving for illicit drugs among drug abusers who also smoke tobacco. In addition, scientists say, patients in drug treatment programs may be less likely to successfully stay off drugs if they are cigarette smokers. These are the findings from two studies published this month in the journal Experimental and Clinical Psychopharmacology.
The two studies, said NIDA Director Dr. Alan I. Leshner, "add very strong behavioral evidence to other research that suggests common characteristics and interactions between tobacco use and opiate and cocaine use. They also suggest that smoking cessation programs should be offered as part of other drug treatment programs."
One study, led by Dr. Stephen Heishman at NIDA's Intramural Research Program, examined the interaction of craving for nicotine and other drugs, using a technique of "cue-induced craving." The study involved male and female adult smokers with histories of drug abuse who were not interested in quitting smoking. In the first part of the study, 18 subjects were asked to listen to scripts-recorded descriptions of scenes-with pleasant (watching children on a sunny beach), unpleasant (a friend asking to borrow money), or neutral (doing household chores) content. At the same time, some of the scripts depicted people expressing a desire to smoke, while other scripts did not mention smoking. In the second part of the study, 24 subjects listened to scripts with only positive emotional content (enjoying the beach, talking on the phone with an old acquaintance, or visiting friends). These positive scripts included increasingly intense descriptions of tobacco craving-from no mention of smoking to asking the question "how could you really enjoy yourself fully unless you were smoking?" After the subjects listened to the scripts they were asked to rate their urge to smoke and their desire to use other drugs.
The investigators found that the scripts mentioning smoking and the scripts containing negative emotional content increased the subjects' experiences of tobacco craving. And, in the second phase of the study, tobacco craving increased as the intensity of the craving messages in the scripts increased.
"One of our more interesting findings was that scripts which elicited craving for tobacco also elicited craving for the subject's drug of choice. This suggests that real-world situations that produce tobacco craving may also result in craving for drugs of abuse," Dr. Heishman explained. "These findings may have important implications for the concurrent treatment of tobacco dependence and other drug dependencies."
In the second NIDA-supported study, Dominick Frosch, a doctoral student at San Diego State University/University of California, San Diego Joint Doctoral Program in Clinical Psychology, and his colleagues at the Integrated Substance Abuse Program at the University of California, Los Angeles, studied the relationship between levels of cigarette smoking and levels of drug use among 32 individuals enrolled in a heroin treatment program. The participants included heavy (20 to 40 cigarettes per day) smokers, nonsmokers, and "chippers" who smoked fewer than 5 cigarettes per day. All of the participants had been in a methadone treatment program for at least 4 months. The researchers evaluated the connection between tobacco smoking and illicit drug use among the smokers and nonsmokers by using breath and urine samples from the participants over a 7-day period. They found that the amount of cocaine and heroin use was directly related to the level of tobacco use. "The more cigarettes smoked, the more likely the person was to use illegal drugs," Frosch said.