This book offers a step-by-step guide to mental health assessment for bariatric surgery patients. A general introduction explains the concepts of bariatric psychology and psychiatry, their relevance in contemporary bariatric surgery, and reasons to include psychologists and psychiatrists in multidisciplinary teams taking care of bariatric patients. The following four chapters address the aspects of mental health that are investigated by bariatric psychology. The psychological processes analyzed here play a major role in influencing patients’ perception of the outcomes of bariatric surgery and in determining their commitment to lifestyle changes and follow-up programs. The second part of the book includes nine chapters addressing the clinical conditions relevant to bariatric psychiatry. For each condition, the major focus is on the impact of psychopathology on bariatric surgery outcomes (weight loss, weight regain, quality of life) and the impact of surgery on its course (remission, worsening, de novo onset). Each chapter in this part includes a discussion of the diagnostic instruments (i.e., structured interviews, clinician-rated tests, and patient-rated tests) that should be used to obtain a valid assessment of the patient’s mental status. Separate chapters focus on psychiatric complications (e.g., suicide and addiction transfer) and psychological problems related to quality of life (e.g., body image dissatisfaction) that may emerge postoperatively. Data on these postsurgery conditions has been reported only recently and, therefore, no published book deals with them. The final chapter offers an overview of unsolved issues in bariatric psychology and psychiatry and reviews emerging research findings that are likely to change assessment and care of bariatric patients’ mental health in the near future. Given its scope—and its wealth of tables, diagrams, mnemonics, and key fact boxes—the book will be an invaluable reference tool for clinicians.