Adolescent development involves complex changes in neurobehavioral systems underpinning the control of emotion and behavior. The adolescent transition is often difficult -- morbidity and mortality increase 300% during adolescence with the majority of the serious health problems related to difficulties with the control of behavior and emotions (e.g., suicide, homicide, depression, alcohol, nicotine, and other substance abuse). A critical gap in advancing research is the general lack of basic knowledge about human brain development during puberty and adolescence. In recent years, however, there have been several areas of research progress, and what is critically needed is better integration across disciplines with a specific focus on the neurobehavioral changes during normal adolescent development that contribute to increased risk-taking and/or reward seeking. The intent of this volume is to stimulate further investigations that will have clinical and social policy relevance to a wide range of behavioral and emotional health problems emerging in adolescence.