who we are

CERPSA is led by a team of policy researchers, clinicians, and educators who share a common goal: Improving the way pain is treated and drugs are controlled so that they safely reach the people that need them.


As a science-based nonprofit, we believe that there are good public health reasons for controlling drugs whether antibiotics, prescription opioids, or even medical cannabis. Consequently, the answer is not the elimination of drug controls, only their dramatic improvement so that they are more effective in ensuring access and preventing abuse. Governments rarely determine if the policies they create actually work and how they can be improved. But with your support, we can change that --- and improve the lives of millions of people throughout the state, nation, and world.

Stephen Ziegler, PhD, JD, CERPSA Founder, Director, and Podcast Host


Trained as a social scientist and attorney, Dr. Ziegler has dedicated his career to the reduction of human pain and suffering in various positions, focusing his efforts on the evaluation of drug control policies, access to essential medicines, and the treatment of pain for almost two decades. He is an author, peer reviewer for medical journals, research grant recipient, chair & panel discussant at medical conferences; invited public speaker (domestic and international); a Mayday Pain and Society Fellow; a Mayday Pain Scholar; as well as an experienced public servant in all three branches of government and has a sense of humor. Prior to his work in pain management and policy, Dr. Ziegler gained experience and insight regarding drug control policy as an assistant prosecutor, defense attorney, appellate attorney, police officer, detective, Drug Abuse Resistance Education officer, and as a Task Force Officer for the U.S. Department of Justice, Drug Enforcement Administration.

Michael C. Barnes, JD, Board Member 

Mr. Barnes is the Chairman of the Center for U.S. Policy, a not-for-profit organization advancing solutions to the nation's substance abuse, mental health, and incarceration crises.  He is also Managing Partner and Founder of DCBA Law & Policy, a law firm recognized nationally for its work in health care and drug policy.  Mr. Barnes previously co-created and successfully exited a global health care and policy consulting firm and a private residential substance abuse treatment program. He also co-founded a not-for-profit that provided early leadership to address the U.S. drug abuse, addiction, and overdose crisis. Mr. Barnes often provides legal, political, and issue analysis for national news networks, including FOX News, FOX Business, CNBC, CNN, and HLN.  He has been a member of the advisory board for the Rx Drug Abuse & Heroin Summit since 2011, the National Sheriffs' Association's Drug Enforcement Committee since 2014, and the editorial board for the Journal of Opioid Management since 2015. Mr. Barnes was a political appointee under President George W. Bush, having served as confidential counsel in the White House Office of National Drug Control Policy.

Joseph G. Bush, MBA, Board Member

Mr. Bush has extensive experience in all facets of healthcare from project and account management to direct sales, new channel development, and             management of strategic partnerships. He brings nearly 25-years of business development at the C-Suite level with a strong focus on building rapport and relationships. Leadership author Tom Peters says, “true leaders don’t create followers, they create more leaders.” Joe’s great passion is mentoring and developing others by sharing his knowledge and experience in order to ensure their success. He’s developed and sold new products and services across industries, all while assuring client delight through top-notch service, and often says that while other people may be smarter, more educated or have more experience, no one will ever out-work him, nor care more for their business partners. Whether it’s sales and marketing or business development and operations management, Joe always finds a way to make a positive impact on everyone he meets and every project he undertakes. A resident of Colorado since 1973, his educational background includes MBAs from Regis University in Operations Management and Finance, respectively, and a B.A. in Economics from the University of Colorado at Boulder. Joe believes in full transparency and aggressive truthfulness in his everyday life and in all of the projects he’s part of. He also has an overt love for 80s and 90s pop culture, and for his dog, Mikey.

Bob Twillman, Ph.D., Board Member


Dr. Twillman is a pain management psychologist at Saint Luke’s Health System in Kansas City, MO, and Clinical Associate Professor of Psychiatry and Behavioral Sciences (Volunteer Faculty) at the University of Kansas School of Medicine in Kansas City, KS. He also is the former Executive Director of the Academy of Integrative Pain Management.  In that capacity, Dr. Twillman was responsible for guiding the organization in its efforts to promote an integrative approach to managing pain.  He formerly served the Academy for four years as its Director of Policy and Advocacy. Dr. Twillman received his Ph.D. in Clinical Psychology at the University of California in Los Angeles.  Prior to working for the Academy, Dr. Twillman was a full-time faculty member at the University of Kansas Medical Center, where he founded and directed the inpatient pain management program and was a co-founder of the hospital’s Palliative Care Team.  Dr. Twillman also served for many years as Chair of the Prescription Monitoring Program Advisory Committee for the Kansas Board of Pharmacy.

Lynn R. Webster, M.D., Board Member


Dr. Webster is vice president of Scientific Affairs for PRA Health Sciences. He is board certified in anesthesiology, pain medicine, and addiction medicine. He lectures extensively and has authored more than 300 scientific publications. He has also conducted hundreds of clinical trials with a major emphasis on analgesics and studying the abuse potential of drugs.  Dr. Webster is a senior editor of Pain Medicine and a past president of the American Academy of Pain Medicine (AAPM). He is the author of The Painful Truth: What Chronic Pain Is Really Like and Why It Matters to Each of Us (Oxford University Press) and co-producer of a documentary with the same title. 

Contact Us

789 Sherman Street, Suite 250
Denver, CO 80203



a project of the Colorado Nonprofit Development Center

© 2020 The Center for Effective Regulatory Policy & Safe Access (CERPSA) & Pain Politics