Mate now delves into the neuroscience of addiction. The opioid and dopamine systems are both vitally involved. We TSM advocates know the role of the opioid system, but the dopamine aspects add new wrinkles.
The dopamine reward system is triggered by anticipation of the pleasurable act, or even by simply thinking about it. We read earlier, in The Heart of Addiction, that relief from the pressure of addiction comes from the moment when we say "screw it" and decide to go ahead with it. Mate is explaining the neuroscience of that bit of psychology.
This, I believe, explains why TSM often takes a while to work. Although the opioid system is disrupted by the naltrexone, the dopamine system is still in place and giving us some satisfaction from the addiction. It's about association, and we've spent a long time associating alcohol with the endorphin rush, thereby making alcohol into its own dopamine reward system.
An approach which disrupted both systems might make us all into those lucky three-pill cure folks.
Addicts are deficient in both opioid and dopamine receptors when compared to non-addicted people. It's not totally clear whether this is the cause of or the result of addiction. Of course, there's no reason why it couldn't be both -- some people are especially vulnerable, they fall prey, and the addiction seems to help while making the underlying neurological problem worse. We often see a downward spiral in addiction.