With these caveats in mind, our results have several treatment implications. As suggested by previous studies, the association of the Val/Val genotype with greater withdrawal severity, worse cognitive performance and greater negative subjective effects suggests that smokers with this genotype, especially female smokers, may experience greater difficulty with smoking cessation. If greater activity of the COMT enzyme is associated with a poor treatment response for smoking cessation, then COMT inhibitors such as tolcapone and entacapone may improve outcomes for smoking cessation in smokers with the Val/Val genotype. Pharmacological COMT inhibition via increased synaptic DA levels improved working memory function and reduced marijuana craving (66–68). This treatment may be especially helpful for female smokers if it is provided immediately after the quit date, when the withdrawal severity is high and smokers are most likely to relapse.
