2026-2027 | On-Demand Session | Neurobiology of Addiction | August 2026-Neurobiology of Addiction Recording

Video Transcription

Video Summary

The lecture introduced the neurobiology of addiction for clinicians, emphasizing that addiction is a complex, whole-brain and whole-body disorder rather than a problem of one neurotransmitter or one brain region. Dr. Roach outlined basic definitions: risky use can progress to substance use disorder, and “addiction” generally refers to compulsive, habitual use despite harm.<br /><br />He reviewed major theories of addiction in historical order. The earliest models focused on the brain’s reward circuitry, especially the mesolimbic dopamine system and the nucleus accumbens, leading to the dopamine hypothesis of reward. Over time, evidence showed dopamine is important for motivation, learning, cue reactivity, and effortful seeking, but not simply for pleasure or “liking.” Drugs, natural rewards, stress, and aversive stimuli can all involve dopamine, and dopamine-based treatments have not solved addiction.<br /><br />He then described later models, especially incentive sensitization, which separated “wanting” from “liking,” and frontal-striatal and aberrant learning theories, which highlighted the role of the prefrontal cortex, glutamate pathways, and the dorsal striatum in compulsive, habitual drug seeking. The most recent major model, allostasis, explains addiction as a shift from positive reinforcement to negative reinforcement, where people continue using to avoid withdrawal and negative affect.<br /><br />Dr. Roach stressed that these theories are useful but incomplete, often based heavily on animal research and not enough on human heterogeneity. He closed by noting that understanding the brain can help clinicians explain addiction to patients, families, and colleagues, improve empathy, and guide treatment.

Keywords

addiction

neurobiology

dopamine

reward circuitry

mesolimbic pathway

nucleus accumbens

incentive sensitization

prefrontal cortex

glutamate

dorsal striatum

allostasis

negative reinforcement

substance use disorder

compulsive use

habitual drug seeking