19. Addiction

Addiction is a neuropsychological disorder characterized by a persistent and intense urge to use a drug or engage in a behavior that produces an immediate psychological reward, despite substantial harm and other negative consequences. Repetitive drug use can alter brain function in synapses similar to natural rewards like food or falling in love in ways that perpetuate craving and weakens self-control for people with pre-existing vulnerabilities. This phenomenon – drugs reshaping brain function – has led to an understanding of addiction as a brain disorder with a complex variety of psychosocial as well as neurobiological factors that are implicated in the development of addiction. While mice given cocaine showed the compulsive and involuntary nature of addiction, for humans this is more complex, related to behavior or personality traits.