Susan M. Knell holds a PhD in Clinical Psychology and a MA in Developmental Psychology. She is the author of the book, Cognitive Behavioral Play Therapy (1993) which has been translated into Italian and Turkish. As the first to study and write about the application of Cognitive Behavior Therapy to young children, she integrated Cognitive Behavioral interventions and Play therapy in developmentally sensitive ways. She has written chapters on CBPT in many edited books on Play Therapy. As a clinical Psychologist, she has provided assessment and therapeutic services to children, adolescents, and adults for almost 40 years. In addition to her clinical practice, she supervises graduate students, trains mental health professionals internationally, and has done research and teaching.