[Role of dopamine in drug dependence processes].

Recent neurobiological data have indicated that almost all drugs of abuse (amphetamine, cocaine, morphine, heroin, cannabis...) increase dopamine release in a sub-cortical structure, the nucleus accumbens. This nucleus is part of different cerebral structures, named "reward system" which constantly defines physical and mental states of an individual. Development of addiction would be due to the modification, by drugs of abuse, of the kinetic and the amplitude of dopamine release. Such a dysregulation would induce the addict to artificially memorize any event linked to the product consumption.