Beyond Dopamine: How Your Brain’s Opioid System Controls the Ability to Feel Pleasure Anhedonia after addiction is endogenous opioid depletion — not just dopamine receptor loss. Mu-opioid receptors in the nucleus accumbens shell mediate the actual experience of pleasure, while dopamine drives motivation toward it. When abstinence restores dopamine but ignores the opioid system, wanting returns without liking. ...
When Habits Become Hardwired: The Dorsal Striatum Circuit That Turns Choice Into Compulsion The habit vs addiction brain distinction is not a severity spectrum. A habit runs on the dorsomedial striatum, a goal-directed circuit that updates when consequences change. An addiction runs on the dorsolateral striatum, an automatic circuit that responds to cues and ignores outcomes. Once control has migrated, willpower targets the wrong subsystem. ...
How Reward Prediction Errors Reprogram Your Brain’s Value System The reward prediction error addiction mechanism describes how substances exploit a learning signal the brain cannot turn off. Dopamine neurons fire when an outcome exceeds prediction. Substances generate an outcome that always exceeds prediction. The error signal never decays, the value calculator keeps over-weighting the substance, and natural rewards are outbid at the level of the circuit itself. ...
