The Oxford Handbook of Treatment Processes and Outcomes in Psychology presents a multidisciplinary approach to a biopsychosocial, translational model of psychological treatment across the lifespan. It describes cutting-edge research across developmental, clinical, counseling, and school psychology; social work; neuroscience; and psychopharmacology. The Handbook emphasizes the development of individual differences in resilience and mental health concerns including social, environmental, and epigenetic influences across the lifespan, particularly during childhood. Authors offer detailed discussions that expand on areas of research and practice that already have a substantive research base such as self-regulation, resilience, defining evidence-based treatment, and describing client-related variables that influence treatment processes. Chapters in newer areas of research are also included (e.g., neuroimaging, medications as adjuncts to psychological treatment, and the placebo effect). Additionally, authors address treatment outcomes such as evaluating therapist effectiveness, assessing outcomes from different perspectives, and determining the length of treatment necessary to attain clinical improvement. The Handbook provides an entree to the research as well as hands-on guidance and suggestions for practice and oversight, making it a valuable resource for graduate students, practitioners, researchers, and agencies alike.