Michael P. Twohig, PhD, is professor at Utah State University, former president of the Association of Contextual Behavioral Science, and peer-reviewed ACT trainer. He has published over one hundred peer-reviewed papers on the application of ACT to obsessive-compulsive and related disorders.Foreword writer Randy O. Frost, PhD, teaches abnormal psychology at Smith College in Northampton, MA. He is coauthor of Buried in Treasures.