The molecular genetic observations reported here are consistent with substantial heritabilities for nicotine dependence vs nondependence and for successful abstinence vs unsuccessful abstinence, as suggested by classical genetic studies [3,6-8,10,11]. The current data support the idea that nicotine dependence shares substantial heritable features with dependence on other addictive substances. These molecular results also support the idea that some of the genetics of nicotine dependence overlaps with the genetic underpinnings of successful abstinence while some is independent.
