This is an academic paper that provides an overview of the neurobiology and neuroscience of opioid use disorder (OUD), with diagrams showing the parts of the brain affected and the science underlying the high risk of recurrence of OUD symptoms.
Koob, G.F. (2020). Neurobiology of Opioid Addiction: Opponent Process, Hyperkatifeia, and Negative Reinforcement. Biological Psychiatry, 87(1), 44-53.