Clinical Team


Cornerstone’s Arizona Clinical Team

Our adept and caring Arizona clinical staff are committed to melding traditional and innovative therapeutic methods, ensuring every individual’s personalized and thorough recovery journey. With a variety of experiences and qualifications in addiction therapy, counseling, and mental health support, our clinical team enhances our multifaceted treatment approach, laying the groundwork for a transformative healing space. 

Dr. Stacey Smith PHD

Chief Clinical Officer

Stacey is a licensed psychologist in Arizona and Texas and has worked in the addiction field in residential and IOP settings since 2010. He has a wide variety of experience in addiction, including working with individuals who suffer from addictions to alcohol, drugs, intimacy/relationships, sex, and gaming addictions. Early in his career, Dr. Smith trained in EMDR techniques, knowing the critical role that trauma work plays in the recovery process. Most recently, an examination of how the brain works and how technology can play a crucial role in client recovery has been a focus of his work.

Medical Director | Phoenix

Dr. Yar Khan earned his medical degree at the Medical University of the Americas in Nevis, West Indies. He completed his clinical training in the United States in Houma and New Orleans, Louisiana, and Chicago, Illinois. He then performed his internship and residency in internal medicine at the Mercy Hospital and Medical Center in Chicago, Illinois. Certified by the American Board of Internal Medicine, Dr. Yar Khan has special interests in outpatient primary care and hospitalist medicine including critical care. He has proficiency in endotracheal intubation, central venous catheterization, paracentesis, thoracentesis, lumbar puncture, and arthrocentesis. 

Clinical Director

Lionel is a Licensed Independent Substance Abuse Counselor (LISAC) and has been with Cornerstone for over 4 years, beginning as a Primary Therapist then moving into the Clinical Director role. Lionel’s passion for helping people shattered by addiction has led him to become a fully trained EMDR therapist as well as a Certified Clinical Trauma Therapist. “Recognizing that drugs and alcohol are only part of the equation has opened my heart and mind to becoming trauma informed in my approach to helping our most broken fellow human beings.”

Nate Bush

Clinical Director | Phoenix

Nate began his recovery journey May 5th of 2010. In January of 2013 he enrolled as a student at Central Arizona College later transferring to Arizona State University where he graduated with his Masters in Social Work with a focus in Adult Behavioral Health Direct Practice. He has been working in the Behavioral Health field since September of 2013. Today he is a Licensed Master Social Worker practicing as a Primary Therapist (and Clinical Lead). In addition to his personal recovery experience, among other things, Nate brings specialties in CBT, DBT, and the treatment of grief, as well as a personal passion for helping others to the family here at Cornerstone Healing Center.

Still have questions about treatment?

Our admissions specialists are here to explain the process, answer any questions you may have, and ensure you’re getting the help you need to live a healthy life free from addiction.

Get Started

Call and speak with one of our caring team members about help for you or a loved one.