In writing this book, the authors have emphasised current perspectives on the neurobiology of mental disorders, not attempting to provide an exhaustive coverage of the field. Each chapter of the book represents a synthesis of the subject's state of the art. The first and third chapters were written by one of the Editors (FGG) and the sixth by the other (MLB). Each of the remaining chapters was extensively revised by one the authors. The book is a single-volume overview on the neurobiology of mental disorders, and was written for a broad audience. The authors aimed at the generally educated reader, who enjoys science and is interested in becoming acquainted with the remarkable new discoveries about how the nervous system executes mental functions. For this reason, they have provided, inside text boxes, background knowledge on the most relevant topics of each field. The authors hope that students from many areas will find here a clear and readable introduction to the present topic.