The devastating psychological, physical, and spiritual damage wrought by the misuse of drugs is indisputable. However, there is a recurring debate over the causes of substance abuse that typically divides along two common assumptions: People either abuse drugs and alcohol out of sheer pleasure-seeking drives run amok or to escape or assuage aversive states of comorbid anxiety or depression. Substance Abuse and Emotion goes beyond this dichotomy in its exploration of recent, significant field observations, theory construction and rigorous testing, and laboratory research to advance working models for a new research paradigm on substance abuse and comorbidity. Notably, the relationship between drugs and emotion is emerging as paramount in understanding drug abuse etiology, maintenance, and relapse. Part I of this edited volume examines various theoretical perspectives on the interrelationship between substance abuse and emotion, such as craving and positive/negative reinforcement; cognitive theories; relapse; and developmental, sociobiological, and evolutionary perspectives. Part II explores new assessment methodologies, such as ecological momentary assessment and the linkage between affect and cognitive deficits among drug users. The book concludes with a research agenda to expand the volume s new paradigm in understanding and treating substance abuse.