[Tobacco dependence].

The present review discusses the potential of nicotine psychic and physical dependence. Since the 1964 Surgeon General's Report on Smoking and Health, much attention has been given to nicotine dependence. Many epidemiological studies indicated that about 50% of smokers could be nicotine dependent; however, few of them had the experience of "progressive neglect of alternative pleasures or interest in favour of smoking." Additionally, some clinical and experimental data indicated that nicotine could not be considered more addictive than cocaine and morphine. As to the physical dependence on nicotine, the nicotine withdrawal syndrome is reported to be observed in about 30% of smokers. However, symptoms of the nicotine withdrawal syndrome are not specific but can appear in smokers put under stress. Several investigators have reported that signs of nicotine withdrawal in experimental animals are weaker than those with opioids, barbiturates and alcohol, and have indicated that it is unclear whether behaviors observed in animal models of nicotine physical dependence are signs of the nicotine withdrawal syndrome. From the current review, it can be considered that the potential for nicotine dependence may not be higher than that for other drug dependence and that nicotine physical dependence potential may be weaker than hitherto believed.