Addiction refers to a complex and chronic brain illness influenced by the environment and genes. It is characterized by substance abuse or compulsive behaviors that persist despite negative consequences. Commonly abused substances include intoxicants like heroin and alcohol, and milder stimulants like nicotine and caffeine. Addiction is recognized as a mental illness and it causes significant economic, health, and social difficulties. Addiction medicine is a subspecialty of medicine that involves the diagnosis, evaluation, prevention, and treatment of addiction. Neuroscience can be used to study the brain mechanisms behind behaviors related to addiction, in order to further the understanding of the addictive processes. It also studies the actions of drug abuse. This book aims to understand the role of neuroscience in the field of addiction medicine. It covers in detail some existent theories and innovative concepts revolving around the prevention and rehabilitation of addictive behaviors. The readers would gain knowledge that would broaden their perspective with respect to this area of medicine.