W Stewart Agras, MD, is a professor emeritus of psychiatry at the Stanford University School of Medicine, Stanford, California, USA. His research is focused on the efficacy, effectiveness, and mechanisms of evidence-based psychotherapies for the treatment of eating disorders in both adolescents and adults and in the implementation of variants of evidence-based treatments in community settings.

Gerhard Andersson, PhD, is a professor of clinical psychology at Linköping University, Sweden. His research focuses on internet interventions for a range of psychiatric and somatic disorders and conditions. He is also active as a clinician and researcher in the field of audiology/hearing disorders.

Paul W Andrews, PhD, is an associate professor in the Department of Psychology, Neuroscience, and Behaviour at McMaster University, Hamilton, Ontario, Canada. His research on depression as an evolved adaptation to promote rumination has been published in prominent psychology and neuroscience journals and received widespread media attention, including The New York Times.

Joanna J Arch, PhD, is an associate professor of psychology and neuroscience at the University of Colorado Boulder, USA. Her research focuses on developing and evaluating interventions designed to address anxiety disorders as well as to improve well-being among anxious adults with cancer, with a focus on mindfulness and acceptance-based interventions.

Scott A Baldwin, PhD, is a professor of psychology at Brigham Young University, Provo, Utah, USA. His research focuses on methodological and statistical issues in psychotherapy research and related fields. His primary substantive interest is in therapist effects and improving psychotherapy outcomes.

Jacques P Barber, PhD, is a professor and dean of the Derner School of Psychology at Adelphi University, New York, USA, and a professor at the University of Pennsylvania and adjunct professor of psychiatry at NYU Medical School. His research focuses on the efficacy and processes of change of dynamic and cognitive psychotherapies for various disorders.

Michael Barkham, PhD, is a professor of clinical psychology at the University of Sheffield, England. He is a member of the PEARLS Research Lab, and his research focuses on conducting pragmatic trials and analyzing very large practice-based datasets to enhance treatment effectiveness and understand patient and therapist variability.

Thomas Berger, PhD, is a professor of clinical psychology and psychotherapy at the University of Bern, Switzerland. His research focuses on internet-based interventions, psychotherapy process and outcome research, training of therapists, psychotherapy integration, and transdiagnostic vulnerability factors.

James F Boswell, PhD, is an associate professor of clinical psychology at the University at Albany, SUNY, New York, USA, where he directs the Practice Oriented Research Lab. His research focuses on psychotherapy process and outcome, practice-research integration, and measurement-based care.

Jonathan B Bricker, PhD, is a professor of public health at the Fred Hutchinson Cancer Research Center and affiliate professor of psychology at the University of Washington, Seattle, USA. He leads the NIH-funded Health and Behavioral Innovations in Technology (HABIT) research lab, which focuses on developing, testing, and disseminating theory-based behavioral interventions for health behavior change.

Gary M Burlingame, PhD, is Warren & Wilson Dusenberry professor and chair of psychology at Brigham Young University, Provo, Utah, USA. He is the incoming president of the American Group Psychotherapy Association and past president of APA Society of Group Psychology and Psychotherapy. His research focuses on measurement and small group treatments.

Louis G Castonguay, PhD, is a liberal arts professor of psychology at Penn State University, University Park, Pennsylvania, USA. His research focuses on the process and outcome of psychotherapy, as well as on practice-research networks and practice-based evidence.

Zachary D Cohen, PhD, is a clinical psychology researcher at University of California–Los Angeles, USA, and is currently leading an effort within UCLA's Depression Grand Challenge to develop and disseminate personalized digital therapies for depression, anxiety, trauma, and sleep problems. His work focuses on developing data-driven approaches to treatment selection and personalization.

Mary Beth Connolly Gibbons, PhD, is an associate professor of psychiatry at the Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA, where she is director of the Center for Psychotherapy Research. Her studies evaluate the comparative effectiveness of treatments for depression and the effectiveness of a therapist feedback system in community settings.

Michael J Constantino, PhD, is a professor of clinical psychology at the University of Massachusetts–Amherst, USA, where he directs the Psychotherapy Research Lab. His research centers on patient, therapist, and dyadic factors in psychosocial treatments; pantheoretical principles of clinical change (common factors); therapist effects and responsivity; and measurement-based care.

Alice E Coyne, MS, is a graduate student at the University of Massachusetts–Amherst, USA, where she is a member of the Psychotherapy Research Lab. Her research aims to identify, and to develop ways to capitalize on, patient, dyadic, and therapist characteristics and processes that can enhance the efficacy of psychotherapy.

Paul Crits-Christoph, PhD, is a professor of psychiatry at the Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA. His recent research has focused on the process of psychotherapies for diverse disorders and patient preferences for different treatments.

Kim de Jong, PhD, is an assistant professor of clinical psychology at Leiden University, South Holland, the Netherlands, and chair of the International Network Supporting Psychotherapy Innovation and Research into Effectiveness (INSPIRE). Her research combines basic science and practice-based methods to improve outcomes for patients and therapists in routine mental health care.

Jaime Delgadillo, PhD, is a senior lecturer in clinical psychology and a member of the PEARLS Research Lab in the Psychology Department at the University of Sheffield, England. His research focuses on outcome monitoring, prediction, and feedback in routine mental health care.

Robert J DeRubeis, PhD, is a professor of psychology and director of clinical training at the University of Pennsylvania, Philadelphia, USA. He has conducted comparative clinical trials of treatments for major depression and has made empirical and methodological contributions to the prediction and understanding of the processes of therapeutic change and the maintenance of gains made in therapy.

Gary M Diamond, PhD, professor, Department of Psychology, Ben-Gurion University of the Negev, Beersheba, Israel, has developed and tested family-based treatments for depressed and suicidal adolescents, and for sexual and gender minority young adults and their non-accepting parents. His research focuses on change mechanisms, such as the therapeutic alliance, emotional processing, and parental acceptance.

Robert Elliott, PhD, is a professor of counseling at the University of Strathclyde, Glasgow, Scotland. A psychotherapy research methodologist, his research focuses on outcomes and change processes in emotion-focused and other humanistic experiential psychotherapies. He is a fellow in the Divisions of Psychotherapy and Humanistic Psychology of the American Psychological Association.

Catherine F Eubanks, PhD, is an associate professor of clinical psychology at the Ferkauf Graduate School of Psychology of Yeshiva University, New York City, New York, USA, and associate director of the Mount Sinai-Beth Israel Brief Psychotherapy Research Program. Her research focuses on alliance ruptures, alliance-focused training, and therapist skills across theoretical orientations.

Evan M Forman, PhD, is the director of the Center for Weight Eating and Lifestyle Science and professor of psychology at Drexel University, Philadelphia, Pennsylvania, USA. He conducts NIH-supported research developing innovative technological and behavioral approaches to health behavior change, and is the author of Effective Weight Loss: An Acceptance-Based Behavioral Approach.

Myrna L Friedlander, PhD, professor, Department of Educational and Counseling Psychology at the University at Albany/SUNY, USA, teaches doctoral seminars on psychotherapy processes and outcomes. Her research focuses on therapeutic change processes, particularly the working alliance, within individual psychodynamic, couple and family therapies, and relational processes in psychotherapy supervision.

Brandon A Gaudiano, PhD, is a professor of psychiatry and public health at Brown University, Providence, Rhode Island, USA. He is primary faculty at the Brown Mindfulness Center, and his work centers on developing and testing transitions of care and acceptance- and mindfulness-based interventions for individuals with severe mental illness.

Simon B Goldberg, PhD, is an assistant professor of counseling psychology at the University of Wisconsin–Madison, USA. His research focuses on psychological interventions to promote well-being. His primary interests include meditation-based interventions and improving psychotherapy outcomes through augmenting transtheoretical factors.

David A F Haaga, PhD, is a professor of psychology at American University, Washington, DC, USA, where he teaches a cognitive behavior therapy practicum for doctoral students. His research interests include assessment, cigarette smoking cessation, and treatment of trichotillomania.

Laurie Heatherington, PhD, is Edward Dorr Griffin professor of psychology at Williams College, Williamstown, Massachusetts, USA, where she teaches clinical psychology courses and conducts research on the family therapy alliance, cognition and other change processes in family therapy, and therapeutic interventions in community and global mental health settings.

Clara E Hill, PhD, is a professor at the University of Maryland, College Park, Maryland, USA, and has been president of the Society for Psychotherapy Research and Society for the Advancement of Psychotherapy, as well as editor of Journal of Counseling Psychology and Psychotherapy Research. Major research interests are helping skills, psychotherapy process and outcome, training and supervision, meaning in life, qualitative research, and dream work.

Steven D Hollon, PhD, is the Gertrude Conaway Vanderbilt professor of psychology at Vanderbilt University, Nashville, Tennessee, USA. His research focuses on the nature and treatment of depression with an emphasis on enduring effects of the cognitive behavioral interventions. He has over 350 publications and has mentored more than 20 doctoral and postdoctoral advisees.

Rachel L Horn, BA, is a doctoral candidate in clinical psychology at Harvard University, Cambridge, Massachusetts, USA. Her research uses machine learning to generate individualized estimates of treatment outcome, creating models that may be used to assist clinicians with treatment assignment.

Shigeru Iwakabe, PhD, is a professor of clinical psychology at Ochanomizu University, Bunkyō-ku, Tokyo, Japan. His research focuses on the process and outcome of affect-oriented integrative psychotherapy as well as cultural issues associated with practice and training of psychotherapy.

Robin B Jarrett, PhD, is a professor of psychiatry and holds the Elizabeth H. Penn Professorship in Clinical Psychology at the University of Texas Southwestern Medical Center, Dallas, Texas, where her laboratory evaluates the role of psychosocial factors and interventions on the course of health in mood and related disorders.

Adrienne S Juarascio, PhD, is an assistant professor at the Center for Weight Eating and Lifestyle Science and Department of Psychology at Drexel University, Philadelphia, Pennsylvania, USA. Her work is focused on developing and evaluating new treatment approaches for eating disorders with an emphasis on the use of mindfulness and acceptance-based treatments.

Alan E Kazdin, PhD, ABPP, is Sterling professor of psychology and child psychiatry at Yale University, New Haven, Connecticut, USA. His 800+ publications include 50 books that focus on psychosocial interventions, parenting and child rearing, interpersonal violence, and research methodology. In 2008, he was president of the American Psychological Association.

John (Jack) R Keefe, PhD, is a research fellow at Albert Einstein College of Medicine in the Bronx, New York, USA. His research interests involve using information about individual patients to improve treatment of treatment-resistant mental illness by adapting treatments or matching patients to therapies, and LGBTQ mental health.

Matthew C Keller, PhD, is a professor of psychology and neuroscience at the University of Colorado at Boulder, USA, and a faculty fellow of the Institute for Behavioral Genetics. His work examines the genetic architecture of psychiatric disorders and other complex traits.

Sarah Knox, PhD, is a professor in the Department of Counselor Education and Counseling Psychology, in the College of Education at Marquette University, Milwaukee, Wisconsin, USA. She currently serves as Co-Editor-in-Chief of Counselling Psychology Quarterly. Her research interests focus on supervision and training, the therapy process and relationship, and qualitative research.

Mariane Krause, PhD, is a professor at Pontificia Universidad Católica de Chile's School of Psychology, Chile, where she is currently the dean of the Faculty for Social Sciences. Her areas of research are change processes in psychotherapy, depression, and the interaction between sociocultural conditions and mental health.

Michael J Lambert, PhD, is a professor emeritus of psychology at Brigham Young University, Provo, Utah, USA. His research has emphasized psychotherapy outcome, process, and the measurement of change. He was a developer of the OQ-45 and editor of the fifth and sixth editions of Bergin and Garfield's Handbook of Psychotherapy and Behavior Change.

Heidi M Levitt, PhD, is a professor of psychology at the University of Massachusetts, Boston, USA. She is a past-president of the Society for Qualitative Inquiry in Psychology. She chaired the American Psychological Association's task force on Journal Article Reporting Standards for qualitative and mixed methods research for their Publication Manual.

Wolfgang Lutz, PhD, is a professor of clinical psychology and psychotherapy and director of the psychotherapy research and training program at the University of Trier, Trier, Germany. His research focuses on classifying different trajectories of treatment change and illustrating how empirically derived clinical recommendations can be applied to personalize mental health care.

Marta M Maslej, PhD, is a postdoctoral fellow with the Krembil Centre for Neuroinformatics at the Centre for Addiction and Mental Health, Toronto, Canada. Her current research explores psychosocial and cognitive factors contributing to treatment outcomes in depression using methods from machine learning and natural language processing.

John McLeod, PhD, is a professor emeritus of counseling at Abertay University, Dundee, Scotland. He is the author of books and articles on case study and qualitative methods in psychotherapy research, and has been involved in the development of a collaborative, flexible, pluralistic framework for therapy practice.

Kevin S McCarthy, PhD, is associate professor of psychology at Chestnut Hill College, Philadelphia, Pennsylvania, USA, and director of Psychotherapy Curriculum in the Psychiatry Residency Program in the Perelman School of Medicine at the University of Pennsylvania. His research focuses on processes of change in psychotherapy.

J Christopher Muran, PhD, is an associate dean and professor at the Gordon F. Derner School of Psychology, Adelphi University, New York, USA. He is also principal investigator, Mount Sinai Beth Israel Psychotherapy Research Program, and on faculty at Icahn School of Medicine at Mount Sinai. His research has focused on alliance rupture repair.

Benoit H Mulsant, MD, is a professor and the Labatt Family Chair of the Department of Psychiatry, University of Toronto, Ontario, Canada, and a senior scientist at the Centre for Addiction and Mental Health (Toronto). The overarching goal of his work is to improve the treatment of persons with severe mental illness.

Michelle G Newman, PhD, is a professor of psychology and psychiatry at Penn State University, University Park, Pennsylvania, USA. Her research focuses on the nature and treatment of anxiety and mood disorders, including the etiology and classification, individual predictors of psychotherapy outcome, and impact of brief psychotherapy with respect to these disorders.

Mei Yi Ng, PhD, is an assistant professor of clinical psychology at Florida International University, Miami Florida, USA. She directs the Mechanisms Underlying Treatment Technologies (MUTT) Lab at the Center for Children and Families. Her research focuses on examining change mechanisms and processes of evidence-based psychotherapies and personalizing interventions for depressed adolescents.

Jesse Owen, PhD, is a professor in the Counseling Psychology Department at the University of Denver, Denver, Colorado, USA. He is also the senior research advisor at SonderMind. His research focuses on promoting therapists' expertise and multicultural orientation, as well as examining processes and outcomes of couple/relationship interventions.

Andrew C Page, PhD, is a professor of psychological science and pro vice-chancellor, research, at the University of Western Australia, Perth, Australia. His research aims to improve the efficiency and effectiveness in routine clinical practice, most recently by predicting self-harm and suicide. This has often been conducted in collaboration with Perth Clinic.

Shireen L Rizvi, PhD, ABPP, is a professor of clinical psychology at Rutgers University, New Brunswick, New Jersey, USA. She received her doctorate from the University of Washington under the mentorship of Dr. Marsha Linehan. She has published widely in the areas of dialectical behaviour therapy, borderline personality disorder, and suicidal behaviors.

Julian A Rubel, PhD, is an assistant professor of psychotherapy research at Justus Liebig University Giessen, Hesse, Germany. His research focuses on the development of empirically supported tools to prevent treatment failure and premature termination.

Jessica L Schleider, PhD, is an assistant professor of psychology at Stony Brook University, Stony Brook, New York, USA, where she directs the Lab for Scalable Mental Health. The objective of her research is to develop brief, accessible interventions for youth depression and anxiety; identify change mechanisms underlying their effects; and test novel approaches to dissemination.

Zindel V Segal, PhD, is distinguished professor of psychology in mood disorders at the University of Toronto, Scarborough, Canada. His program of research characterizes psychological markers of relapse vulnerability in affective disorder which, in turn, provide an empirical rationale for offering training in mindfulness meditation to recurrently depressed patients in recovery.

Jason Sharbanee, PhD, is a lecturer in clinical psychology at Edith Cowan University, Joondalup, Australia. His research focuses on the process of change in emotion-focused and experiential therapies. He is the director of the Western Australian Institute of Emotion Focused Therapy, and maintains a small private practice at Cygnet Clinic.

Daisy R Singla, PhD, is a clinician scientist and assistant professor at the Center of Addiction and Mental Health and in the Department of Psychiatry at the University of Toronto, Ontario, Canada. As a clinical psychologist by training and global health researcher at heart, her primary research interests involve scaling up evidence-based psychological interventions for depression and anxiety.

William B Stiles, PhD, is a professor emeritus of psychology at Miami University, Oxford, Ohio, USA, adjunct research professor of psychology at Appalachian State University, Boone, North Carolina, USA, and senior research fellow at Metanoia Institute, London, UK. He has written about psychotherapy process and outcome, verbal interaction, and research methods.

Bernhard Strauss, PhD, is a full professor of psychotherapy and medical psychology, head of the Institute of Psychosocial Medicine, Psychotherapy, and Psycho-Oncology at Friedrich-Schiller-University Jena, Thuringia, Germany, and is past president of the German College of Psychosomatic Medicine, German Society for Medical Psychology, and the Society for Psychotherapy Research. His research focuses on (group) psychotherapy, attachment, and psychological interventions in medicine.

Ladislav Timulak, PhD, is associate professor at Trinity College Dublin, Ireland. He is course director of the Doctorate in Counseling Psychology. His main research interest is the development of emotion-focused therapy. He currently is adapting this form of therapy as a transdiagnostic treatment for depression, anxiety and related disorders.

Kevin E Vowles, PhD, is a professor of clinical health psychology at Queen's University, Belfast, Northern Ireland. His work has examined treatment effectiveness, clinical significance, and mechanisms of change. Recent work has concentrated on identifying distinctive characteristics of effective pain rehabilitation and differentiating problematic from non-problematic opioid use.

Bruce E Wampold, PhD, is senior researcher at the Institute at Modum Bad Psychiatric Center and professor emeritus of counseling psychology at the University of Wisconsin in Madison, Wisconsin, USA. Currently his work involves understanding psychotherapy from empirical, historical, and anthropological perspectives.

Jeanne C Watson, PhD, is professor in the Department of Applied Psychology and Human Development at the University of Toronto, Ontario, Canada, and APA fellow in the Division of Psychotherapy. A major exponent of emotion-focused therapy (EFT), she has co-authored nine books and conducts research on EFT, cognitive behavioral therapy and humanistic psychotherapies.

John R Weisz, PhD, ABPP, grew up in Mississippi, got his BA from Mississippi College, Clinton, Mississippi, and his MS and PhD from Yale University, New Haven, Connecticut. He is a professor of psychology at Harvard University, Cambridge, Massachusetts, USA. He leads the Harvard Lab for Youth Mental Health, and with his colleagues and students develops and tests mental health interventions for children and adolescents.

Soo Jeong Youn, PhD, is the director of evaluation at Community Psychiatry PRIDE at Massachusetts General Hospital, and an assistant professor in psychiatry at Harvard Medical School, Boston, Massachusetts, USA. Her research focuses on psychotherapy process/outcome, community-based participatory research, and implementation science to address the access to care problem in mental health.

Sigal Zilcha-Mano, PhD, is a professor of clinical psychology and the head of the Psychotherapy Research Lab in the Department of Psychology, University of Haifa, Israel. Her research focuses on improving mental health through the personalization of treatment by facilitating change in individual-specific therapeutic mechanisms.