Mario Cossa, MA, RDT/MT, TEP, CAWT is a psychodramatist, drama therapist, and theatre educator who has conducted workshops and has presented at conferences in the U.S.A., Canada, England, South Africa, Malaysia, Australia and New Zealand.  Mario is a certified trainer in the Therapeutic Spiral Model (TSM) for the safe use of psychodrama with survivors of trauma.

Sylvia Israel, MFT (MFC 31245), is a nationally Certified Psychodrama Trainer (TEP), Registered Drama Therapist/Trainer (RDT/BCT) and Founder//Director of IMAGINE! Center for Creativity & Healing and Bay Area Playback Theater.  She on the faculty of the California Institute of Integral Studies (CIIS), and has presented at Spirit Rock Meditation Center. Sylvia is a Fellow of the American Society for Group Psychotherapy and Psychodrama (ASGPP). She maintains a private practice in Marin and San Francisco.

John Olesen, MA, PAT, is a Psychodramatist living in Oakland, California and working at the L.I.F.E. (Learning Immune Function Enhancement) Program of the non-profit organization, Shanti, in San Francisco.  He is past Chair of the National Board of Examiners for Group Psychotherapy and Psychodrama and was co-chair of the 2006 ASGPP Conference in San Francisco.  He is a past recipient of the ASGPP Neil Passariello and Zerka T. Moreno Awards.

Elizabeth Plummer, PhD is a licensed clinical psychologist (CA 19690) and a nationally certified clinical practitioner of psychodrama/ trainer applicant (CP/PAT).  Dr. Plummer has taught psychodrama at conferences around the country.  She is the founder and director of The Santa Barbara Psychodrama Center, teaches at Antioch University, and has a private practice in Santa Barbara.

Jo Sopko, MFT (MFC38054), a Registered Drama Therapist, has used Sandtray for over 15 years both clinically and in education. She wasTrauma Specialist at Homeward Bound of Marin where she specialized in working with homeless children and families. She is adjunct faculty at the California Institute of Integral Studies , teaching clinical supervision for The  Expressive Arts Therapy Program  . She uses mindfulness practice and meditation in her work, and is dedicated to the use of art as a powerful tool toward healing. She has a private practice in Marin and San Francisco.