Emerging pharmacotherapies for alcohol use disorder.

The identification of different stages within the alcohol use disorder (AUD) cycle that are linked to neurocircuitry changes in pathophysiology associated with the negative emotional states of abstinence has provided a view of medication development for AUD that emphasizes changes in the brain reward and stress systems. Alcohol use disorder can be defined as a chronic relapsing disorder that involves compulsive alcohol seeking and taking, loss of control over alcohol intake, and emergence of a negative emotional state during abstinence. The focus of early medications development was to block the motivation to seek alcohol in the binge/intoxication stage. More recent work has focused on reversing the motivational dysregulations associated with the withdrawal/negative affect and preoccupation/anticipation stages during protracted abstinence. Advances in our understanding of the neurocircuitry and neuropharmacological mechanisms that are involved in the development and maintenance of the withdrawal/negative affect stage using validated animal models have provided viable targets for future medications. Another major advance has been proof-of-concept testing of potential therapeutics and clinical validation of relevant pharmacological targets using human laboratory models of protracted abstinence. This review focuses on future targets for medication development associated with reversal of the loss of reward function and gain in brain stress function that drive negative reinforcement in the withdrawal/negative affect stage of addiction. Basic research has identified novel neurobiological targets associated with the withdrawal/negative affect stage and preoccupation/anticipation stage, with a focus on neuroadaptive changes within the extended amygdala that account for the transition to dependence and vulnerability to relapse. This article is part of the Special Issue entitled "Alcoholism".