Addiction is a progressive disorder that involves a transition from social use into a
compulsive relapsing state. This behavioral transition reflects a combination of transient and
enduring neural adaptations within specific neural circuits that can leave individuals
vulnerable to relapse—even following prolonged periods of abstaining from drug use.
Commonalities in the ability of abused drugs to promote similar changes in neurochemistry,
neurophysiology, and behavior have pushed for a unified theory of substance abuse. While …