Aetiology, Neurobiology, and Course | Week 2 - Day 2 | Substance Use Disorders and Addictions

Welcome to Neurotorium Educational Series

In Week 2 of the Neurotorium Educational Series, psychiatrists, psychiatry trainees, and medical trainees in Uganda dive deeper into Substance Use Disorders and Other Addictions, moving from diagnostic foundations into the neurobiology that drives addictive behaviour.

The session begins with an overview of the training series and its goal of strengthening neuroscience knowledge through peer-led learning. Kemi highlights that the previous meeting explored the definitions, epidemiology, and diagnostic formulation of substance use disorders, and this week’s focus shifts to the brain mechanisms behind addiction.

Dr. Raymond presents on the general neurobiology of addiction, explaining how psychoactive substances alter neurotransmitter systems—especially dopamine—and how these changes shape reward, motivation, and compulsive use. He breaks down the major pathways involved, including:

Mesolimbic & Mesocortical pathways

Tuberoinfundibular pathway

Nigrostriatal pathway

He also explains how chronic drug use leads to reduced dopamine receptors, impaired executive function, and lasting changes in brain circuitry.

Dr. Mugume follows with a focused look at the neurobiological effects of alcohol, nicotine, and cannabis, showing how:

Alcohol disrupts multiple systems, including GABA and opioid pathways

Nicotine acts on nicotinic acetylcholine receptors across the brain

Cannabis activates cannabinoid receptors, with THC causing psychoactive effects and CBD offering medicinal potential

The team ends with a reminder that all presentation slides, recordings, and educational materials are available on the Neurotorium website, ensuring participants can review and deepen their learning.

This week continues to build on the broader curriculum covering:

Definitions & Epidemiology

Diagnostic Formulation

Aetiology & Neurobiology

Course of Addiction

Treatment Principles, Comorbidity & Prognosis