Neuroscience perspectives on addiction: Overview

Abstract

Substance addiction can be a chronic relapsing disorder. While different drugs of addiction have different primary molecular targets, it has been demonstrated that many share the common action of being able to increase dopamine within hardwired reward circuitry. While this effect is widely conceived as a primary factor driving initial drug use, long-term adaptations within this hard-wired neural circuitry underlie the transition from drug use to drug dependence. Significantly, these neuroadaptations are responsible for triggering recurrent drug relapse in people recovering from addiction, even when following periods of long-term abstinence. While there is no animal model of addiction that can fully emulate the human condition, some animal models do permit the investigation of specific elements of drug addiction, particularly those involving the reward system and its role in drug-seeking behavior. Neuroimaging methods now also permit us to test hypotheses of addiction derived from such animal models, allowing the field of neuroscience to examine neural components of drug abuse and dependence in humans. These neuroimaging procedures permit neuroscientists to test hypotheses in humans at different stages of the addiction cycle, particularly with a view to developing better treatments.