Our Physicians

Timothy L. Carpenter, D.O.

Timothy L. Carpenter, D.O.Dr. Timothy Carpenter grew up in the Mississippi delta in Greenwood, Mississippi. After graduating from Ole Miss with a bachelor of science degree, he attended medical school at Kansas City University of Medicine and Biosciences. He completed an internal medicine-focused internship with Saint Louis University and his general psychiatry training at the University of California-Irvine Medical Center. Dr. Carpenter is board certified in psychiatry by ABPN and in addiction medicine by ABAM. He has experience treating all adult populations, including the geriatric population, in many settings (inpatient hospitals, partial hospitalization, intensive outpatient, outpatient, crisis stabilization units, urgent care, nursing homes, and skilled nursing facilities).

Yelena Chistyakova, M.D., Ph.D.

Yelena Chistyakova, M.D., Ph.D.Yelena Chistyakova, M.D., Ph.D. is an adult psychiatrist who relocated to Montgomery in 2012 to join Alabama Psychiatric Services. Dr. Chistyakova worked as an internist in the Ukraine after she completed her studies at the Ukrainian Academy of Medicine and Dentistry in 1986. She completed two years of her fellowship at the Kharkov Endocrinology Research Institute and three years of research in psychosomatic medicine at the Kharkov Institute of Advanced Medical Training in the Ukraine and completed her doctorate degree there. After completing Ross University Medical School in 2005, she received adult psychiatry training at the University of Iowa Hospital and Clinic and continued work as an associate in the department of psychiatry at Carver Medical School in Iowa City, IA. She was the medical director of an inpatient eating disorder treatment program and partial hospitalization eating disorder treatment program before relocating to Montgomery to join APS.

Gary L. Gay, D.O.

Gary L. Gay, D.O.Before coming to IBH, Dr. Gay was in private practice for about 10 years in Churchville, Maryland. He also provided independent psychiatric care at clinics in Maryland for almost 20 years. Dr. Gay holds certification at the American Board of Psychiatry and Neurology and has extensive experience seeing patients from six years up to 99+.

Dr. Gay received his bachelor’s degree in Psychology from the University of Maryland, Baltimore County, Baltimore, Maryland. He earned his medical degree from West Virginia School of Osteopathic Medicine.

He completed an internship in psychiatry at the Cleveland Clinic Foundation, Cleveland, Ohio and he finished his psychiatry residency at The Sheppard and Enoch Pratt Hospital, Baltimore, Maryland.

Dr. Gay lives in Dothan with his wife, Cristine, and their young daughter Olivia but is excited to be moving into the north Alabama area. When they are not traveling and when he can break away from his many duties, Dr Gay enjoys playing guitar.

Jason Greenhagen, D.O.

Jason Greenhagen, D.O.Dr. Jason Greenhagen is originally from Tennessee and graduated from Lincoln-Memorial University, DeBusk College of Osteopathic Medicine in 2014. He then completed his general psychiatry residency at Rowan School of Osteopathic Medicine in 2018, where he also held the title of chief resident. After his residency, he specialized in geriatric psychiatry at the New Jersey Institute for Successful Aging. He is licensed to practice in Alabama and Tennessee. His major interests include maintaining independence and dignity for the elderly as well as working with patients with varying types of dementia.

John Hammond, M.D., Ph.D.

John Hammond, M.D., Ph.D.Dr. John Hammond started his journey to becoming a geriatric psychiatrist at Lafayette College in Pennsylvania and continued on through his time as a research assistant at Johns Hopkins University until finally enrolling here in the state of Alabama at the University of Alabama in Birmingham. He completed his Doctorate of Medicine and of Philosophy and psychiatric residency at the University of Alabama in Birmingham in 2017 and has completed his geriatric psychiatry fellowship at the University of Alabama in Birmingham.

Jun Liu, M.D.

Jun Liu, M.D.Dr. Liu joined IBH after graduating from the University of South Alabama Psychiatry Residency in 2019, where she served as chief resident for her fourth year. She also worked as a moonlighting physician for Altapointe Health Systems. She obtained her medical degree at the University of South Alabama Medical School in 2015. Dr. Liu went to undergraduate at the Massachusetts Institute of Technology, where she double majored in Brain and Cognitive Sciences and Music. She worked in labs at MIT and Columbia University studying visual perception and neuronal testing and continued to explore these areas as a laboratory assistant at UCLA piloting multitasking studies using MRI techniques on human subjects. Dr. Liu relocated to Alabama where she received her training in medicine. Dr. Liu continues to combine her passion for psychology with her interests in providing quality medical care.

Bryant K. Mahaffey, M.D.

Bryant K. Mahaffey, M.D.Bryant K. Mahaffey, MD has been in the healthcare field since 2006, when he entered the University Of Alabama School Of Medicine at UAB in Birmingham, Alabama. He graduated medical school in 2010 and matched into the UAB Psychiatry Residency Program. During his residency, he fulfilled training in General Psychiatry and the administration of ECT. Upon completion of his residency in 2014, he obtained board certification with the American Board of Psychiatry & Neurology and began employment as staff psychiatrist for Decatur Morgan Hospital West. In the ensuing years, he has continued to develop professionally, assumed the role of Medical Director at Decatur West in 2016, and established an ECT service for patients in the Tennessee Valley. Now, he is excited to be a part of IBH and to have the opportunity to continue to grow as a practitioner.

Sanjay Malhotra, M.D., ABNP (DIP), Founder and Chairman

Sanjay Malhotra, M.D., ABNP (DIP), Founder and Chairman of BoardDr. Malhotra has over 15 years of expertise in Adult and Geriatric Psychiatry. He is a graduate of Maulana Azad Medical College in New Delhi, India and is Board Certified in General and Geriatric Psychiatry. He has been a dedicated physician serving in a multitude of medical and psychiatric capacities since starting his career, and has been awarded numerous designations including Medical Director, Chief of Psychiatry, and Coroner. He specializes in clinical program development and operations, staff training and development, quality improvement, and outcomes management. Dr. Malhotra is dedicated to providing comprehensive, high quality mental health services to his patients, caregivers, and families. His passion is the treatment of Alzheimer's disease and other dementias.

Timothy Whalen, M.D., Medical Director

Timothy Whalen, M.D., Medical DirectorDr. Timothy Whalen is no stranger to the quad cities and was at the APS Florence office from 2006 to 2015. Before that, he worked for 10 years in private practice in Maryland and five years in public psychiatry serving the residents of coastal North Carolina. He finished his training in psychiatry at John Hopkins Hospital in Baltimore, Maryland, after completing medical school at Ohio State University. Dr. Whalen served his internship at Riverside Methodist Hospital in Columbus, Ohio in family practice. Dr. Timothy Whalen practices child, adolescent, and adult psychiatry in the Muscle Shoals office of IBH. He enjoys working with families and patients of all ages.