We found that smokers with the Val/Val genotype, compared to the Met carriers, had greater negative subjective effects from IV nicotine and more severe withdrawal severity following overnight abstinence from smoking. Women with the Val/Val genotype reported greater difficulty concentrating and irritability than men with the Val/Val or Met allele containing genotypes. The Val/Val genotype was associated with better performance on the math task and in AA smokers, it was associated with greater systolic blood pressure readings. These findings are consistent with most of our hypotheses regarding COMT Val158Met polymorphism effects on nicotine responses.
