Zindel Segal, PhD, is Distinguished Professor of Psychology in Mood Disorders at the University of Toronto-Scarborough. He is Director of Clinical Training in the Clinical Psychological Science Program and is also Professor in the Department of Psychiatry. Dr. Segal has conducted influential research into the psychological processes that make certain people more vulnerable than others to developing depression and experiencing recurrent episodes. He actively advocates for the relevance of mindfulness-based clinical care in psychiatry and mental health. He collaborated with John Teasdale and Mark Williams in developing mindfulness-based cognitive therapy (MBCT) to prevent relapse and recurrence in major depression; together, they coauthored Mindfulness-Based Cognitive Therapy for Depression, Second Edition (for mental health professionals), as well as the self-help guides The Mindful Way Workbook and (with Jon Kabat-Zinn) The Mindful Way through Depression. Mark Williams, DPhil, is Professor of Clinical Psychology Emeritus at the University of Oxford Department of Psychiatry, where he was Founding Director of the Oxford Mindfulness Centre. He collaborated with John Teasdale and Zindel Segal in developing mindfulness-based cognitive therapy (MBCT) to prevent relapse and recurrence in major depression; together, they coauthored Mindfulness-Based Cognitive Therapy for Depression, Second Edition (for mental health professionals), as well as the self-help guides The Mindful Way Workbook and (with Jon Kabat-Zinn) The Mindful Way through Depression, Second Edition. Dr. Williams continues to train mindfulness teachers internationally. John Teasdale, PhD, held a Special Scientific Appointment with the United Kingdom Medical Research Council's Cognition and Brain Sciences Unit in Cambridge. He is a Fellow of the British Academy and the Academy of Medical Sciences. He collaborated with Mark Williams and Zindel Segal in developing mindfulness-based cognitive therapy (MBCT) to prevent relapse and recurrence in major depression; together, they coauthored Mindfulness-Based Cognitive Therapy for Depression, Second Edition (for mental health professionals), as well as the self-help guides The Mindful Way Workbook and (with Jon Kabat-Zinn) The Mindful Way through Depression. Since retiring, Dr. Teasdale has taught mindfulness and insight meditation internationally. He continues to explore and seek to understand the wider implications of mindfulness and meditation for enhancing our way of being.