Nikolaos Kazantzis, PhD, has worked in clinical, training, and research settings for over two decades. He is founder and director of the Cognitive Behavior Therapy Research Unit. His research focuses on processes within the therapeutic relationship, how they directly support treatment changes and client engagement, and how they can be reliably assessed by trained observers and supervisors. He is a Beck Scholar, a Fellow of the Australian Psychological Society,and the Delegate for Australia of the International Association for Cognitive Therapy. In 2020, he is serving as Guest Editor for the scholarly journals Cognitive Therapy and Research, Cognitive and Behavioral Practice, Frontiers in Psychiatry, Frontiers in Psychology, and Psychotherapy Research. He is also continuing his term as Associate Editor for Cognitive Therapy and Research, is incoming Editor for Cognitive and Behavioral Practice, and is Editor of Springer Nature's "CBT: Science into Practice" book series.

Mark A. Reinecke, PhD, is Professor of Psychiatry and Behavioral Sciences and Chief of the Division of Psychology at Northwestern University’s Feinberg School of Medicine. He serves on the staff of Northwestern Memorial Hospital and Children’s Memorial Hospital, Chicago. He is a Distinguished Fellow and former president of the Academy of Cognitive and Behavioral Therapies and a Diplomate of the American Board of Professional Psychology. His research and clinical interests focus on understanding and treating depression and suicide among children and adolescents. Dr. Reinecke's numerous publications include seven books.

Arthur Freeman, EdD, LLD (h.c.), ABPP, until his death in 2020, was Professor Emeritus of Psychology at the Philadelphia College of Osteopathic Medicine. A leading expert on cognitive-behavioral therapy, he was a past president of the Association for Behavioral and Cognitive Therapies and of the International Association for Cognitive Psychotherapy, and a Distinguished Founding Fellow of the Academy of Cognitive and Behavioral Therapies. Dr. Freeman's research and clinical interests included marital and family therapy and cognitive-behavioral treatment of depression, anxiety, and personality disorders. The author of over 100 chapters and articles, he lectured in 45 countries and his work has been translated into 20 languages.