Delay discounting demonstrates lower impulsivity linked to a higher likelihood of succeeding at smoking cessation

Sixty-eight percent of smokers want to quit, but only one in 10 are successful at smoking cessation. Recently, impulsivity has been studied in relation to smoking cessation with measures like the delay discounting task (DDT). We aimed to build on the robust literature that has already revealed the association between impulsivity and smoking cessation, as well as look at the differences between sexes for which there is conflicting evidence. We hypothesized that lower impulsivity would be positively associated with cessation success. In the parent cessation trial, participants were randomized to 12 weeks of progesterone or placebo. Participants were asked to quit smoking, and their smoking status was monitored via expired carbon monoxide throughout the study. Participants completed a DDT at screening, week 4, and week 8 using the 27-item Monetary Choice Questionnaire, where participants decided between a small immediate reward or a larger delayed reward (LDR). The effective delay 50 (ED50), which is the delay at which the LDR loses half its value, was analyzed. To estimate the association between ED50 and cessation, a logistic mixed model with a participant random intercept was fit, controlling for study week, randomization, sex, and age. For the 181 participants, a doubling of the ED50 was associated with an 18% increase in the odds of tobacco cessation (95% confidence interval: 0.2-38% increase; p=0.05). In agreement with our hypothesis, lower impulsivity correlated to greater tobacco cessation success. Our study also showed no evidence of sex differences in the association between ED50 and smoking cessation.