Association of the dopamine-β-hydroxylase gene with nicotine dependence: No evidence for mediation by personality

DBH genotype appears to be associated with nicotine dependence. The association we report appears to be independent of age, sex and personality, and both age and psychoticism were independently associated with nicotine dependence. Different phenotype definitions employed by previous studies, such as cigarette consumption rather than nicotine dependence, may explain inconsistency in the published findings.