Costas Papageorgiou is Senior Lecturer at Lancaster University and was Deputy Director of the Specialist Service for Affective (Mood) Disorders in Manchester. He obtained a BSc from the University of Buckingham and an MA and a Doctorate in Clinical Psychology from the University of Liverpool. Dr. Papageorgiou has expertise in the assessment and treatment of depression. He has been extensively involved in investigating rumination and depression and has co-authored the first empirical studies examining the link between rumination, depression, and metacognition.

Adrian Wells is Reader in Clinical Psychology at the University of Manchester and Professor at the Norwegian University of Science and Technology, Trondheim. He is recognized for his contribution to the development of cognitive theory and therapy of emotional disorders. He has published widely in peer-review journals and has authored/co-authored several ground-breaking books in the field.