introduction:Smoking cessation is typically verified biochemically by expired-air carbon monoxide (CO) levels below 9 ppm (i.e., ≤8 ppm), but this CO criterion may lead many who have smoked within 24 hr to be misclassified as abstinent.

Background Smoking acutely relieves negative affect (NA) due to smoking abstinence but may not relieve NA from other sources, such as stressors. Methods Dependent smokers (N=104) randomly assigned to one of three smoking conditions (nicotine or denic cigarettes, or no smoking) completed four negative mood induction procedures (one per session): 1) overnight smoking abstinence, 2) challenging computer task, 3) public speech preparation, and 4) watching negative mood slides. A fifth session involved a neutral mood control. The two smoking groups took 4 puffs on their assigned cigarette, and then smoked those same cigarettes ad libitum during continued mood induction. All subjects rated their level of NA and positive affect (PA) on several measures (Mood Form, PANAS, Stress-Arousal Checklist, and STAI-state). They also rated craving and withdrawal. Results NA relief from smoking depended on the NA source (i.e. mood induction procedure) and the affect measure. Smoking robustly relieved NA due to abstinence on all 4 measures, but only modestly relieved NA due to the other sources and typically on only some measures. Smoking’s effects on PA and withdrawal were similar to effects on NA, but relief of craving depended less on NA source. Smoking reinforcement only partly matched the pattern of NA relief. Few responses differed between the nicotine and denic smoking groups. Conclusions Acute NA relief from smoking depends on the situation and the affect measure used but may not depend on nicotine intake. These results challenge the common assumption that smoking, and nicotine in particular, broadly alleviates NA.

Rationale In animals, nicotine enhances reinforcement from stimuli unrelated to nicotine intake. Human research is suggestive but has not clearly shown a similar influence of nicotine. Objectives We assessed acute effects of nicotine via smoking on enhancement of positive (money, music) or negative (termination of noise) reinforcers, or no “reward” (control). These different rewards determined the generalizability of nicotine effects. Materials and Methods Dependent (n=25) and nondependent (n=27) smokers participated in three sessions, each after overnight abstinence. Using a within-subjects design, sessions involved no smoking or smoking denicotinized (0.05 mg) or nicotine (0.6 mg) QuestR brand cigarettes. For comparison, a fourth session involved no abstinence prior to smoking one’s own brand to gauge responses under typical nicotine satiation. Reinforcement was assessed by responses on a simple operant computer task for the rewards, each available singly on a progressive ratio schedule during separate trials. Results The reinforcing effect of music, but not other rewards, was greater due to the nicotine cigarette, compared to the denicotinized cigarette or no smoking. Reinforcement enhancing effects of nicotine did not differ between dependent and nondependent groups, indicating no influence of withdrawal relief. Responding due to acute nicotine after abstinence was very similar to responding one’s own brand after no abstinence. Conclusions Acute nicotine intake per se from smoking after abstinence enhances the reinforcing value of rewards unassociated with smoking, perhaps in a manner comparable to ad lib smoking after no abstinence. Nicotine’s reinforcement enhancing effects may be specific to certain rewards, perhaps those sensory in nature.

Puff topography and subjective measures during the ad lib smoking of a single cigarette are highly reliable. Smoking responses during a single ad lib smoking session may be useful in identifying stable individual differences in smoking reinforcement and reward.

Rationale-Negative mood increases smoking reinforcement and may do so to a greater degree in smokers vulnerable to negative mood dysregulation.Methods-Adult smokers (N = 71) without current depression were randomly assigned to one of two smoking conditions (nicotine or denic cigarettes, presented blind) maintained across all sessions. Subjects completed one neutral mood session and four negative mood induction sessions. Negative mood inductions included one each of the following: 1) overnight smoking abstinence, 2) challenging computer task, 3) public speech preparation, 4) watching negative mood slides. In each session, subjects took 4 puffs on their assigned cigarette, rated it for "liking" (reward), and then smoked those cigarettes ad libitum (reinforcement) during continued mood induction. Affect was assessed intermittently before and after smoking. Differences in responses were examined as functions of selfreported history of major depression and levels of distress tolerance and anxiety sensitivity.Results-Smoking reinforcement, but not reward or negative affect relief, was greater in all sessions in those with a history of depression and greater after overnight abstinence in those with lower distress tolerance. Reward and affect relief, but not reinforcement, were greater during speech preparation among those high in anxiety sensitivity.