Zindel Segal is the Morgan Firestone Chair in Psychotherapy in the Department of Psychiatry at the University of Toronto. He is Head of the Cognitive Behaviour Therapy Unit at the Centre for Addiction and Mental Health and is a Professor in the Departments of Psychiatry and Psychology at the University of Toronto. His research has helped to characterize psychological markers of relapse vulnerability to affective disorder. Among the books he has authored are Interpersonal Process in Cognitive Therapy, Cognitive Vulnerability to Depression, and Mindfulness-Based Cognitive Therapy for Depression: A new approach for preventing relapse. Awarded the Douglas Utting Prize for significant contributions to the understanding and treatment of depression and the Hope Award by the Mood Disorders Association of Ontario, he continues to advocate for the relevance of mindfulness-based clinical care in psychiatry and mental health.

Mark Williams is Professor of Clinical Psychology at the University of Oxford and Wellcome Trust Principal Research Fellow. From 1983 to 1991 he was Research Scientist at the Medical Research Council's Cognition and Brain Sciences Unit in Cambridge. From 1991 to 2002 he was Professor of Clinical Psychology at the University of Wales, Bangor, where he founded the University's Institute of Medical and Social Care Research (IMSCaR) and the Center for Mindfulness Research and Practice. His research in clinical and experimental psychology focuses on understanding the psychological processes that underlie depression and suicidal behaviour and the development of new psychological treatments. Among the books he has authored are The Psychological Treatment of Depression, Cognitive Psychology and Emotional Disorders Cry of Pain: Understanding Suicide and Self-harm and Mindfulness-Based Cognitive Therapy for Depression: A new approach for preventing relapse. He received the Shapiro Award from the British Psychological Society, and has been elected Fellow of the Academy of Medical Sciences.

John Teasdale has worked as a research scientist, funded by the Medical Research Council, first in the Department of Psychiatry, University of Oxford, then in the Cognition and Brain Sciences Unit, Cambridge. His research has investigated basic psychological processes and the application of that understanding to the relief of emotional disorders. For many years, this research involved the exploration of cognitive approaches to understanding and treating major depression, and he was one of the pioneers of cognitive therapy research in the United Kingdom. More recently, the findings of earlier research have been applied to the development and evaluation of Mindfulness-Based Cognitive Therapy. Among the books he has authored are Affect, Cognition, and Change and Mindfulness-Based Cognitive Therapy for Depression: A new approach for preventing relapse. He has received a Distinguished Scientist Award from the American Psychological Association, and has been elected Fellow of both the British Academy and the Academy of Medical Sciences. He is currently retired, pursuing personal interests in practicing and teaching meditation and mindfulness training.