Drug addiction: pathways to the disease and pathophysiological perspectives.

Drug addiction is a medical condition, a chronic relapsing disease. As in other domains of experimental medicine, appropriate experimental investigations are needed in order to better understand the disease. However, to understand the diverse facets of drug effects and of the underlying pathophysiology it is necessary to keep in mind the complexity of the psychopathological processes. The main symptoms that characterize addiction correspond to expressions of dysfunctions within specific circuits and regions. Pathways to addiction are numerous and comorbidity and in the real world poly-drug use are common. Some of these aspects will be examined as well as the role of life events and stress. Theoretical considerations will be proposed [see also: Koob, G.F., & Le Moal, M.. 2005a. Neurobiology of Addiction. Elsevier. 570 pp] to account for the stages of the disease from impulse control disorder to compulsive disorders, for affective dynamics and for the relations between the symptoms and pathophysiology.