INDIVIDUAL-DIFFERENCES IN SENSITIVITY TO NICOTINE - IMPLICATIONS FOR GENETIC RESEARCH ON NICOTINE DEPENDENCE

Recent evidence suggests that cigarette smoking has a heritability ind ex around 53%. While related research on underlying mechanisms also su pports the idea that genetic factors contribute to nicotine dependence -as well as to cofactors such as substance use and mood disorders-the nature of the behavioral traits and biological capacity for reinforcem ent that constitutes vulnerability to nicotine dependence is not well understood. The present review explores the problem of why some people become highly nicotine dependent, others develop a pattern of occasio nal use, and still others avoid the drug entirely despite extensive ex posure and widespread experimentation with tobacco in the population. Recent research-both infrahuman and human-suggests that vulnerability to nicotine dependence is related to high initial sensitivity to nicot ine and that the development of tolerance is more rapid and self-admin istration more extensive in such individuals. Relevant findings from n euroscience and biobehavioral research are reviewed in order to identi fy variables and methodologies that might improve the reliability and validity of behavioral and molecular genetic studies on cigarette smok ing. The integration of research in these areas may lead to new insigh ts in the understanding of nicotine dependence as well as to improved techniques for prevention and treatment.