Genetic models for the natural history of smoking: evidence for a genetic influence on smoking persistence

Abstract

We reanalyze data from the 1981 mailed questionnaire survey of the Australian twin register, to test for a genetic effect on smoking persistence (whether or not a smoker quits smoking). In the young cohort, aged 18-30 years, there are too few ex-smokers to permit resolution of genetic and non-genetic models. In the older cohort, we find a significant and substantial genetic effect on smoking persistence, accounting for 53% of the variance. This genetic effect on smoking persistence is independent of genetic effects on smoking initiation.