Stress, drug abuse and addiction: neurobiological and behavioral aspects

The onset and the development of drug addiction and vulnerability to relapse following withdrawal are thought to be the result of neuro-adaptive processes within the central nervous system. The long-lasting effects of abused drugs lead to impairment of the mechanisms mediating positive reinforcement but also to the emergence of affective changes such as anxiety, dysphoria and depression during withdrawal. A growing body of evidence suggests the involvement of a cyclic dysregulation of the endocrine and non-endocrine stress control system as a common factor in the development of drug addiction and vulnerability to relapse following withdrawal. A critical element contributing to the chronic relapsing nature of drug addiction are the learned responses to drug-related stimuli.