Dr. Van Doren is an Addiction Medicine and Chronic Pain Specialist at Advanced Pain of Tulsa. He received his B.S. degrees in Chemistry and Biology at Newman College in Wichita, Kansas and his M.D. degree from the University of Kansas School of Medicine in Kansas City, Kansas. Dr. Van Doren completed his Internal Medicine Residency and Fellowships in Medical Oncology and Hematology at the University of Oklahoma Health Sciences Center in Oklahoma City, OK. He worked for over 15 years as a Medical Oncologist & Hematologist in private practice in Oklahoma before pursuing a Fellowship in Addiction Medicine at the University of Oklahoma School of Community Medicine.

He remained as a Faculty Assistant Professor of Internal Medicine at the University of Oklahoma providing and teaching Addiction Medicine and non-interventional chronic pain management. Dr. Van Doren moved into private practice in July of 2016 where he has worked to develop Addiction Medicine programs and provide non-interventional chronic pain management through Pain Management specialty practices.

He was a previous Medical Director for the Mission Treatment Center and is the current Medical Director for the Tulsa Comprehensive Treatment Center. Dr. Van Doren is Board Certified and maintains certification in Internal Medicine through the American Board of Internal Medicine, Addiction Medicine through the American Board of Preventive Medicine, and as a Medical Review Officer through the American Association of Medical Review Officers. He is an active member of the American Medical Association, American College of Physicians, American Association of Medical Review Officers, and is a Fellow of the American Society of Addiction Medicine.

LaWanda Singleton brings over 12 years of experience in the Health Information Management field. She currently serves as the Human Resource Manager, Health Information Management, Credentialing, and HIPAA/Compliance Officer at Great Plains Recovery Center, a Drug and Alcohol Recovery Center dedicated to restoring hope, healing families, and rehabilitating futures. In this role, LaWanda leads human resources operations and ensures rigorous compliance with regulatory standards. Additionally, LaWanda implements policies and procedures for the preparation, maintenance, completion, privacy, and retention of medical records. LaWanda is a dedicated mother of five and holds four degrees in Health Information disciplines.

Ruby Thomas APRN-CNP is a nationally certified Adult Gerontology Primary Care Nurse Practitioner who is specialized in addiction treatment through SAMSHA. She received her Bachelor’s degrees from Oklahoma Wesleyan University and her Master’s degree from the University of Cincinnati. She is a member of the ANCC.  She has over 10 years’ experience with substance abuse, particularly in Opioid Use Disorder. She has been practicing in Tulsa for over 25 years and besides being an NP , she has served in various roles including ER , ICU and several management positions. When she is not at work, she enjoys to spend time with her family and volunteers at community events. She is married and has a daughter that is a physician and a son that is studying to be a CRNA.

Dr. O’Brien comes to Great Plains Recovery with an extensive background in Internal Medicine, Addiction Medicine, and Psychiatry. He received undergraduate degrees in nursing and zoology while completing his Pre-Medical requirements.

Following his undergraduate studies, Dr. O’Brien attended the University of Oklahoma College of Medicine where he was elected “Outstanding Student in Internal Medicine” and ultimately graduated with “special distinction” and was given lifetime appointment to Alpha Omega Alpha, the National Honor Medical society for Physicians.

Next, he completed Internship and Residency in Internal Medicine before embarking on several years in private practice. Over time his practice evolved into full time in Addiction Medicine and he was Medical Director of Mission Treatment Center in Tulsa, OK prior to coming to Great Plains.

Outside of work, Dr. O’Brien believes in hobbies and enjoys doing stained glass, breeding aloes, and playing guitar, bass, and mandolin.