The single most important public health problem facing physicians today may be the failure of patients to follow their prescribed treatment regimens, a phenomenon that results in treatment failures, increased morbidity and mortality, and enormous burdens to society and the economy. This book focuses on the many factors that influence adherence behavior and discusses how this behavior can be improved. Drawing on data from social, personality, clinical, and health psychology, a leading authority on the subject examines the psychosocial, demographic, contextual, and provider determinants of patient compliance with physician recommendations and stresses their multiplicative influence. Alan J. Christensen presents several theories to account for this behavior and then offers his own new interactional framework, one that applies broader fundamental theorizing about psychological and behavior change to the problem and thereby sheds new light on efforts to promote adherence.