Incubation of Cue-Induced Cigarette Craving During Abstinence in Human Smokers

Background: Abstinent drug users remain at risk for relapse long after withdrawal subsides. Animal studies indicate that responses to drug-related cues not only persist but increase with abstinence, a phenomenon termed incubation of drug craving. It is unknown whether cue-induced craving increases, decreases, or remains constant with abstinence in humans. We investigated effects of abstinence on cue-induced craving in cigarette smokers. Methods: Eighty-six non-treatment-seeking, adult smokers (>= 10 cigarettes daily) were paid to abstain for 7 (Group 1), 14 (Group 2), or 35 (Groups 3 and 4) days. Abstinence was verified daily. Groups 1, 2, and 3 underwent a single cue session on the final abstinence day (7, 14, or 35). Group 4 viewed cues on Days 7, 14, and 35. Results: Between and within groups, smoking-cue-induced craving increased with abstinence on some measures. Cue-induced craving was greater in Group 3 (35-day) compared with Group 1 (7-day). Within Group 4, cue-induced craving was greater at 35 than 14 days. Cue-induced craving did not decrease with abstinence on any measure. Conclusions: We present initial evidence of incubation of cue-induced craving in humans. The observation that cue-induced craving increases with abstinence, even as background craving and withdrawal symptoms subside, might have treatment implications.