The role of menthol in cigarettes as a reinforcer of smoking behavior.

The World Health Organization has identified several additives such as menthol in the manufacturing of cigarettes to specifically reduce smoke harshness. These additives may have important implications for reinforcing smoking behavior and motivation to quit smoking. The purpose of this paper is to synthesize research related to the role of menthol's sensory characteristics in strengthening the reinforcing effects of nicotine in cigarettes and the impact on nicotine addiction and smoking behavior. Research reports from 2002 to 2010 on the addictive potential of menthol cigarettes were reviewed that included qualitative focus groups, self-reports and biomarkers of nicotine dependence, human laboratory, and epidemiological studies. Positive sensory effects of menthol cigarette use were identified via reports of early smoking experiences and as a potential starter product for smoking uptake in youth. Menthol cigarettes may serve as a conditioned stimulus that reinforces the rewarding effects of smoking. Nicotine dependence measured by shorter time-to-first cigarette upon waking was increased with menthol cigarette use in most of the studies reviewed. Smoking quit rates provide additional indicators of nicotine dependence, and the majority of the studies reviewed provided evidence of lower quit rates or higher relapse rates among menthol cigarette smokers. The effects of menthol cigarette use in increasing the reinforcing effects of nicotine on smoking behavior were evidenced in both qualitative and quantitative empirical studies. These findings have implications for enhanced prevention and cessation efforts in menthol smokers.