2026-2027 | Live Session | Neurobiology of Addiction | August 2026-Neurobiology of Addiction Presentation

Neurobiology of Addiction Presentation

Pdf Summary

This lecture reviewed the neurobiology of addiction and argued that addiction is best understood as a highly complex, heterogeneous, whole-brain and whole-body disease rather than the result of a single neurotransmitter, brain region, or circuit. It defined addiction as compulsive, habitual substance use despite harm, often corresponding to moderate or severe substance use disorder.<br /><br />The talk traced major theories of addiction history, beginning with the dopamine-based “reward” hypothesis and moving through incentive sensitization, aberrant learning, fronto-striatal dysfunction, and allostasis. A central theme was that early models overemphasized dopamine and the mesolimbic dopamine system, especially the nucleus accumbens, as the brain’s “pleasure center.” While dopamine clearly contributes to motivation, cue reactivity, learning, and effortful behavior, evidence does not support the idea that dopamine alone mediates drug pleasure or reward. Instead, “wanting,” “liking,” and learning are separable processes involving multiple neurotransmitters and circuits; opioids likely play a larger role in hedonic pleasure.<br /><br />The lecture also emphasized that addiction research has historically been biased toward white men and male animals, leaving major gaps in understanding the effects of sex, gender, race, ethnicity, and sexuality. It highlighted limitations of animal models, weak translation to humans, and the difficulty of capturing human heterogeneity and addiction stages in laboratory studies.<br /><br />Additional theories were summarized: incentive sensitization focuses on sensitized cue-driven “wanting”; aberrant learning emphasizes a shift from ventral to dorsal striatum and habit formation; fronto-striatal dysfunction stresses impaired executive control; and allostasis describes progression from positive reinforcement to negative reinforcement and withdrawal-driven compulsive use. However, the lecturer concluded that no single theory fully explains addiction, and recent human data challenge some stage-based models.<br /><br />Current directions include better network-level human studies, methods to model heterogeneity, and new targets such as the gut-brain axis, hallucinogens, metabolic mechanisms, and advanced brain stimulation approaches.

Keywords

addiction neurobiology

substance use disorder

dopamine reward hypothesis

incentive sensitization

aberrant learning

fronto-striatal dysfunction

allostasis

habit formation

cue reactivity

gut-brain axis