Sensitivity of nicotine-containing and de-nicotinized cigarette consumption to alternative non-drug reinforcement: a behavioral economic analysis

A previous report from our laboratory showed similar measures of reinforcing efficacy for nicotine-containing and de-nicotinized cigarettes when each cigarette type was presented alone. The present experiment further compared the reinforcing efficacy of nicotine-containing and de-nicotinized cigarettes by assessing the effects of alternative non-drug reinforcement on self-administration of both cigarette types. Eight human subjects responded on a progressive-ratio schedule in which the number of plunger pulls required for standardized cigarette puffs increased across sessions. Responding for the two types of cigarette was examined when each was available alone and when the concurrent opportunity to earn money was available. Consumption of nicotine-containing and de-nicotinized cigarettes was decreased by both increases in price and by the concurrent availability of money. The two cigarettes types did not differ in their sensitivity to price or alternative non-drug reinforcement. These results replicate our previous report of similar measures of reinforcing efficacy for the two cigarette types when each was presented alone, and extend our previous findings to a choice situation involving an alternative non-drug reinforcer. These data suggest the importance of further examination of non-pharmacological variables in the maintenance of drug taking and the sensitivity of drug taking to alternative non-drug sources of reinforcement. Factors potentially contributing to the maintenance of smoking the de-nicotinized cigarettes (i.e. conditioned reinforcement, primary reinforcement by respiratory stimulation, instructional control, demand characteristics) are also discussed.