Book excerpt: This book is the result of the American Psychological Association's Division of Psychotherapy (Div. 29) Task Force aimed at applying psychological science to the identification and promulgation of effective psychotherapy. Many efforts to improve therapy have focused on codifying evidence-based treatments, but in doing so have left the psychotherapeutic relationship behind. Clinical experience and research findings underscore that the therapeutic relationship accounts for as much of the outcome as particular treatments. This volume's 25 chapters identify the elements of effective therapy relationships and methods of customizing psychotherapy to each patient.