[Psychopharmacological models of drug dependence. Key role of the dopaminergic mesolimbic system].

The potential of a compound to induce drug dependency may be described as an interaction of its positive reinforcing and its discriminative as well as its aversive properties. Environmental factors and conditioning play thereby important, modulating roles. Drugs of abuse act via central mechanisms which mediate basal sensations such as reward and satisfaction. Neurochemical and neuroanatomical investigations suggest a key role of the dopaminergic mesolimbic system in these processes. Addictive drugs from several pharmacological classes have in common to stimulate the dopaminergic mesolimbic system, albeit by different mechanisms. However, other non dopaminergic neurotransmitter systems, e.g. the GABAergic, the opioid or the serotonergic system, are also involved in drug-seeking behaviour.