This book explores the connection between flow (or the mental state of becoming fully immersed in an activity) with a diverse range of physical and mental conditions. It begins with an introduction to the theory of flow and previous research on its social role and health benefits. It then provides an overview of the neurological functions underlying flow as well as instruments and methods for measuring it. The remainder of the book outlines, through a critical discussion of recent clinical research, the relationships between flow and emotional issues such as guilt, shyness, stress, and optimism. The study shows that the promotion of flow can benefit those suffering from negative emotional conditions. This work is significant because it shows areas in which promotion of flow can potentially provide clinical benefits.