Steven C. Hayes, PhD, is Nevada Foundation Professor in the department of psychology at the University of Nevada, Reno. He has been president of numerous professional organizations, is author of forty-five books and nearly 650 scientific articles, and is among the most cited living psychologists. He has shown in his research how language and thought leads to human suffering, and is originator and codeveloper of acceptance and commitment therapy (ACT): a powerful therapy method that is useful in a wide variety of areas; relational frame theory (RFT): an empirical program in language and cognition; and process-based therapy (with Stefan G. Hofmann). Brian Thompson, PhD, is a licensed psychologist and director for the anxiety clinic at the Portland Psychotherapy Clinic, Research, & Training Center in Portland, OR. He specializes in working with anxiety and obsessive-compulsive and related disorders, and publishes research in these areas. Brian Pilecki, PhD, is a clinical psychologist at the Portland Psychotherapy Clinic who specializes in the treatment of anxiety disorders, trauma and PTSD, and matters related to the use of psychedelics. Brian also has extensive experience in the areas of mindfulness and meditation and incorporates them into his therapy with clients. He is an active researcher and has published on topics such as anxiety disorders, mindfulness, and psychedelic-assisted therapy. Joanne Chan, PsyD, is a licensed psychologist and assistant professor of psychiatry at Oregon Health and Sciences University (OHSU) where she provides psychological support to medical and dental faculty, residents, and fellows. Joanne specializes in exposure therapy for anxiety and obsessive-compulsive and related disorders and regularly provides training and education in her areas of expertise.