The American Society of Addiction Medicine (ASAM) defines substance use disorders (SUD) as primary, chronic diseases of brain reward, motivation, memory, and related circuitry. Without treatment or engagement in recovery activities, this is reflected as an individual who is pathologically pursuing reward and/or relief by substance use and other behaviours, despite consequences. As we develop strategies and treatments to prevent use and intervene on early use, knowledge of the neuroscience can improve our ability to respond effectively, and with compassion. Each of the medication developmentÂ targets and psychological strategies employed in the treatment of SUD are tied to specific organÂ systems, most generally the pathways in the brain. Since many of the areas of the brain that areÂ involved with mental disorders overlap those affected by chronic drug use, medications that treatÂ symptoms of anxiety and mood are also useful in changing the incentives and patterns of use. Andrea G Barthwell, MD, DFASAM will present the neuroscience needed to understand SUDs and medications that work on these systems.