The development and validation of a human screening model of tobacco abstinence

Introduction
Given the low efficacy of smoking cessation methods, an experimental medicine model indicating smoking abstinence would be of great benefit to the development of new treatments. Hence the sensitivity of cognitive tasks and ambulatory craving measures to smoking abstinence were investigated.

Methods
Cognitive tasks and ambulatory ratings of craving were assessed for sensitivity to acute abstinence (experiment 1), and nicotine replacement therapy administration (NRT) (experiment 2).

Results
In experiment 1 go/no-go performance was improved (Mean Difference [MD] -0.99, 95% CI: −1.90 to −0.08) and craving was lower (Regression Coefficient [RC] −33.39, 95% CI: -39.96 to -26.82) in satiated compared with abstinent smokers. There was no clear evidence that N-back (MD 0.64, 95% CI: −0.42 to 2.51), delay discounting (MD 0.01, 95% CI: 0.001 to 0.005) or dot probe performance (MD 0.61, 95% CI: −0.87 to 1.54) were sensitive to acute abstinence. In experiment 2 go/no-go performance was improved (MD 1.12, 95% CI: 0.16–2.08) and craving was lower (RC −18.59, 95% CI: −24.63 to −12.55) smokers abstinent overnight receiving NRT compared with placebo. There was no clear evidence that N-back (MD −0.25, 95% CI: −1.45 to 0.94), delay discounting (MD 0.01, 95% CI: -0.002 to 0.004) or dot probe performance (MD −0.49, 95% CI: −1.61 to −0.64) were sensitive to NRT.

Conclusions
Findings from two experiments converge to suggest that abstinence in smokers reliably increases ambulatory craving assessments and, to a lesser extent, decreases go/no-go task performance. These findings can be utilized in the development of an experimental medicine model to test novel treatments for smoking cessation.