David F. Tolin is Founder and Director of the Anxiety Disorders Center at The Institute of Living, USA, and an Adjunct Professor of Psychiatry at Yale University School of Medicine. He was the 2014 President of the Clinical Psychology division of the American Psychological Association, and is a recipient of the Award for Lifetime Contribution to Psychology from the Connecticut Psychological Association. An internationally recognized expert in the study and treatment of hoarding disorder, Dr. Tolin is the author of over 150 scientific journal articles and several books. He was a featured expert on the A&E series Hoarders, hosted the VH-1 series The OCD Project, and has been a recurrent guest on programs such as The Dr. Oz Show and The Oprah Winfrey Show. Bethany M. Wootton is a clinical psychologist and Senior Lecturer in Clinical Psychology at the University of New England, Australia. She has an interest in the treatment of anxiety and related disorders. Her research focuses on the development and evaluation of remote treatments in order to improve access to evidence-based treatments for these conditions. Blaise L. Worden is a clinical psychologist at the Anxiety Disorders Center at the Institute of Living, USA, where she runs and directs cognitive-behavioral treatment groups for hoarding disorder. She has co-authored book chapters on the phenomenology of both hoarding and obsessive-compulsive disorder, and provides educational talks to community organizations about HD treatment. Christina M. Gilliam is a clinical psychologist and Director of Educational Programs at the Anxiety Disorders Center at the Institute of Living, USA. She is an expert in providing and training others in cognitive behavioral therapy for anxiety disorders, obsessive compulsive and related disorders, and she has published journal articles and book chapters in these areas.