Have you ever wondered why some people repeatedly engage in harmful or unproductive actions? Compulsive behaviour is a symptoms of various mental health disorders and a personality trait known as compulsivity. In this lecture, Professor Robbins will explore the psychological basis of compulsions and compulsivity, as well as the mediating role of neural circuitry. He will present evidence from studies involving human neuroimaging and animal models, with a focus on the fronto-striatal systems implicated in goal-directed behaviour and habit. Professor Robbins will also discuss the potential implications of these findings for the future classification and treatment of impulsive-compulsive disorders.