Leadership Team

Since 1999, Dan George has served in leadership roles at the Matrix Institute on Addictions, and then as the Chief Operating Officer for the merged organization, CLARE|MATRIX in 2018 before transitioning into the role of Chief Executive Officer in Fall of 2021. In addition to the administrative hats that Dan has worn, he has also served as a Principal Investigator for several National Institute of Drug Abuse-funded pharmaceutical studies, involving psychosocial treatment approaches for substance use disorders. Likewise, he functioned in Evaluator and Project Director roles for five consecutive Targeted Capacity Expansion HIV grants, funded by the Substance Abuse and Mental Health Services Administration. Dan earned his Master’s Degree in Public Health from California State University at Northridge, with an emphasis on Health Education and Program Design. He completed his MBA from the University of Redlands, with an emphasis on Finance. Dan resides in Los Angeles County, with his wife and two sons.

Dr. David Baron has worked as a global educator and researcher in psychiatry for more than 30 years. He has served as the Medical Director of Global Health and the Assistant Dean of International Affairs for the Keck School of Medicine at USC. He formerly served as an Associate Dean of International Relations for Temple University School of Medicine.

Over the past decade, David has taught a graduate class in Global Mental Health for USC. He currently mentors six international psychiatrists, and he works with a number of international governments to provide opioid addiction education programs for clinicians.

In 1982, the U.S. State Department deployed David to Saudi Arabia to develop psychiatric education for Saudi medical students. Since then, he has stayed very active in international psychiatric education and collaborative research with global partners.

David was an original member of the American Psychological Association (APA) Taskforce, which became the APA Global Mental Health Taskforce. He’s also been very active in the Western Psychological Association, founding a section and serving on leadership roles in multiple sections. David has worked with global psychiatrists to publish numerous papers and textbooks.

Donna L. Johnson has over 25 years of experience working with substance use disorders, criminal justice and integrated care. She has a long history of increasing profitably, growing and enhancing programs, while ensuring quality services for programs in all levels of care.  Donna has significant knowledge of legal/judicial issues and an excellent understanding of organizational systems and processes. She has a special interest in international work, providing consulting, Matrix model training and various behavioral health and criminal justice topics training to many countries that include: South Africa, Netherlands, New Zealand, Australia, Germany, Canada, United Kingdom, to name a few.   Donna believes that staff training, demonstration of skills and clinical supervisions are the keys to quality care and she values the role that Matrix offers to agencies through the training, consulting process and Key Supervision component.

Donna has been a consultant and trainer for the Matrix Institute on Addictions for over 17 years and is the lead author on the Matrix Model for Criminal Justice.  She has also worked as a contributor on several other Hazelden publications, and she is a trainer for Hazelden Betty Ford Foundation.  Donna has written numerous magazine articles and has been featured on CBS Atlanta, PBS, CNN and Fox News on various addiction issues.

She served as the Director for a large community mental health center, overseeing all levels of care including detox, inpatient, crisis stabilization, intensive outpatient, residential, women’s programs and adolescent services.  In addition, she worked in several areas of the criminal justice system including:  corrections, drug courts, community supervision and youth justice.  Donna also worked with a large hospital system to integrate behavioral health and trauma informed care into their primary care system.

Donna founded her own company, Addiction Solutions of Georgia, Inc., where she specialized in consulting and training in substance use disorders, criminal justice, tele-mental health and integrated care. She has provided consulting and training to numerous state addiction authorities, CSAT projects, hospitals, drug courts, agencies, Fortune 500 companies and many criminal justice programs.  Donna has been a speaker and keynote for numerous national and international conferences, including the National Association for Drug Court Professionals Conference and the National Conference on Addictive Disorders and the United Kingdom and European Symposium on Addictive Disorders.

David Melendez has more than 25 years of experience as a non-profit leader and fundraisers. He has held senior position in higher education, social programs, the arts, community development programs, and social entrepreneurial initiatives. He has held senior advancement and development positions in the University of California system, the California California State University system and in private higher education including CSU, Bakersfield, UCLA, Chapman University, CSU Northridge, and Pepperdine University. David has also served as a leader of community-based and national programs including Jumpstart for Young Children, CASA of Los Angeles, College Summit, and Plaza de la Raza. He also also taken part in various professional development programs including non-profit fellowships awarded by Bank of America, Capital One, Washington Mutual and the Center for Non-Profit Management in Los Angeles. he was also awarded a fellowship in multi-cultural education through the James Irvine Foundation and has taken part in the executive leadership program through the Social Innovation Center at Stanford University. David sustains a passion for social justice and community empowerment.

Ken Simms is a proven professional in the Greater Los Angeles Area; he has over 20 years of experience working with small to medium-sized organizations as a key member of executive management. He has worked in multiple industries including service, technology, manufacturing, commercial real estate, and not-for-profit sectors. He has been responsible for business planning, strategic development, cash management, vendor management and monthly closing process. He specializes in systems conversions, operational streamlining. He has participated in due diligence for merger and acquisitions, post-acquisition restructuring, and implemented cost cutting initiatives. He has been responsible to report to bank officials and various board of directors. Additionally, he has managed numerous standard, forensic and municipal audits. Mr. Simms has a BA from the University of Southern California in Business Administration with an emphasis in Accounting.