By one view, drug use blunts dopamine neurotransmission, motivating to overcome DA deficiency; the authors support the other view, that drug use enhances DA neurotransmission, producing a sensitized reaction to drugs

Samaha, Anne-Noël, Shaun Khoo, Carrie R. Ferrario, and Terry E. Robinson. 2020. “Dopamine “ups and Downs” in Addiction Revisited” PsyArXiv. October 30. doi:10.31234/osf.io/8vch5

Rolf Degen's take: https://twitter.com/DegenRolf/status/1322403784572755968

Abstract: Drugs of abuse can change dopamine (DA) function during the development of addiction. But in what direction? By one view, drug use blunts DA neurotransmission, producing a hypodopaminergic state, and drug use is motivated to overcome DA deficiency. Another view is that drug use enhances DA neurotransmission, producing a sensitized, hyperdopaminergic reaction to drugs and drug cues, and continued drug use is motivated by sensitization of drug ‘wanting’. Here we discuss recent studies using intermittent cocaine self-administration procedures that mimic human patterns of use. These studies support the view that addiction-like behaviour involves sensitized DA responses to drugs and drug cues, consistent with human neuroimaging studies. These results have implications for modeling addiction in the laboratory, and for treatment.