Denver Health Mental Health Services Psychiatrists

Robert House, M.D., is the Director of Mental Health Services. He is an Associate Professor and Vice-Chairman representing Denver Health Medical Center for the Department of Psychiatry at the University of Colorado School of Medicine. He is board certified in Psychiatry and Neurology and a distinguished Fellow with the American Psychiatric Association. He received his undergraduate degree from the University of Denver, and graduated from the University of Nebraska College of Medicine. He completed his residency in psychiatry at the University of Colorado School of Medicine. He also completed a fellowship in Consult Liaison Psychiatry at the University of Colorado Health Sciences Center. He is a Colonel, Medical Corps, United States Army Reserve and Command Surgeon, 96th Regional Readiness Command, Ft. Douglas, Utah.

Vincent Collins, M.D., is the Associate Director of Mental Health. He is also an Associate Professor of Psychiatry at the University of Colorado School of Medicine (UCSOM). He received his undergraduate degree from Yale University, and graduated from the University of Pennsylvania School of Medicine. He completed his residency training in pediatrics and in psychiatry at the UCSOM. He is board certified in General Psychiatry and Child and Adolescent Psychiatry. Research interests and areas of clinical expertise include post-traumatic stress disorder, somatoform disorders, and cross-cultural psychiatry.

Richard Martinez, M.D., M.H., is the Director of Forensic Psychiatry of Mental Health. Dr. Martinez is the Robert D. Miller Professor of Psychiatry and Law at the University of Colorado School of Medicine and Director of the Forensic Training Program. He received his undergraduate degree from Tulane University and has a Masters Degree in Humanities from the University of Colorado at Denver. He graduated from Louisiana State University School of Medicine. He completed fellowships in bioethics and professional ethics from Harvard University, and completed a psychiatry residency and a fellowship in forensic psychiatry at the University of Colorado School of Medicine. He has published articles in forensic psychiatry, medical ethics, and a book on professional ethics in forensic psychiatry.

Christian Thurstone, M.D., is an attending physician with the Adolescent Substance Abuse Treatment, Education, and Prevention Program of Behavioral Health. His is also an Assistant Professor at the University of Colorado School of Medicine (UCSOM). He received his undergraduate degree from Duke University and his medical degree from the University of Chicago. He completed a general psychiatry residency at Northwestern University Medical School, child psychiatry residency at the University of Chicago, and an addiction psychiatry fellowship at the UCSOM. He is board certified in General Psychiatry, Child and Adolescent Psychiatry, and Addiction Psychiatry. His research interests include medication development for adolescent substance use disorders.

Greg Kellermeyer, M.D., Director of Correctional Psychiatry, Dr. Kellermeyer leads a team of nurses, mid-level providers, and psychiatrists treating inmates in Denver County Jail and the Van Cise-Simonet Detention Center. He also supervises and teaches the forensic psychiatry fellows who are students of the Forensic Psychiatry Program at Denver Health and the University of Colorado School of Medicine (UCSOM). In addition, Dr. Kellermeyer performs civil and criminal forensic evaluations. Dr. Kellermeyer graduated from the University of Toledo College of Medicine and completed a general psychiatry residency at the UCSOM, where he served as chief resident of neuropsychiatry. He also completed a forensic psychiatry fellowship at UCSOM. Dr. Kellemeyer is the author of numerous abstracts, presentations and lectures in neuropsychiatry and forensic psychiatry.

Kristie Ladegard, M.D., treats adolescents who are dually diagnosed with substance use disorders and psychiatric illness. She provides psychiatric consultation for local schools, and serves as part-time child and adolescent staff for the STEP program and at Denver’s Family Crisis Center. Dr. Ladegard incorporates child psychiatry into school-based medical care, and provides psychiatric services to underserved children and their families. Dr. Ladegard graduated from Creighton University School of Medicine and completed a general psychiatry residency and fellowship in child and adolescent psychiatry at Eastern Carolina University Brody School of Medicine. She is a member of the American Academy of Child and Adolescent Psychiatry and the American Psychiatric Association. Dr. Ladegard is board certified in Psychiatry.

Elizabeth Lowdermilk, M.D., is an adult psychiatrist. Dr. Lowdermilk graduated from the University of Colorado School of Medicine and completed a residency in psychiatry also at the UCSOM, where she also served as Chief Resident.

Mary Stephenson, M.D., is the Director of Outpatient Psychiatric Child and Adolescent Services of Mental Health for Denver Health Medical Center. She is also an Instructor at the University of Colorado School of Medicine. She received her undergraduate degree from Ohio State University and her medical degree from Wright State University School of Medicine. She completed her residency in general psychiatry and her Child and Adolescent Fellowship at the University of Louisville. She is board certified in Psychiatry and Child and Adolescent Psychiatry.

Jon Kusumi, M.D., is an adolescent psychiatrist on the Inpatient Adolescent Psychiatric Unit. He is an instructor at the University of Colorado School of Medicine (UCSOM). He graduated from the UCSOM and completed a residency in general psychiatry at the University of Colorado Department of Psychiatry, where he served as chief resident. He completed a child and adolescent psychiatry fellowship also at the UCSOM.

Douglas Ikelheimer, M.D., is a board-certified staff psychiatrist and the Medical Director of Psychiatric Emergency Services. He is also an Assistant Professor at the University of Colorado Health Sciences Center. His specialties include addiction and emergency psychiatry. He received his medical degree from the State University of New York at Sony Brook, and then received his Master's in Behavioral Neuroscience from Columbia University. He completed his internship and psychiatry residency at Dartmouth-Hitchcock Medical Center before completing his training in addiction psychiatry at the University of Colorado School of Medicine.

Abraham Nussbaum, M.D., M.T.S., is an attending psychiatrist on the adult inpatient service, and an Assistant Professor of Psychiatry at the University of Colorado School of Medicine. He received his undergraduate degree from Swarthmore College. He earned a master’s degree in Medicine and Theology from Duke Divinity School. He completed medical school and general psychiatry residency at the University of North Carolina. His research interests include meta-analysis for antipsychotics and the history of psychiatry.

Charles Shuman, M.D., is a psychiatrist and the Medical Director for Substance Use Disorders Services of Denver Health. He is also as Assistant Professor of Psychiatry at the University of Colorado School of Medicine. He received his undergraduate education, as well as attended medical school, at Temple University. He completed his residency in psychiatry at the University of Florida School of Medicine. Dr. Shuman became board certified with the American Board of Psychiatry and Neurology in Psychiatry in 2007. In 2009, he completed his Addiction Psychiatry Fellowship at the University of Colorado School of Medicine. His specialty is Addiction Psychiatry.

Tamara Chambless, M.D., is a psychiatrist in the Psychiatric Emergency Services unit. Dr. Chambless graduated from the Weill Medical College at Cornell University, and completed her residency at the University of Colorado School of Medicine, where she served as chief resident. Dr. Chambless is board certified by American Board of Psychiatry and Neurology.

John Wiberg, M.D., is a Correctional Systems Psychiatrist. Dr. Wiberg graduated from Stanford University School of Medicine and completed a residency in psychiatry at the University of Colorado School of Medicine, where he served as chief resident.

Dr. Wiberg has practiced in and developed expertise in all fields of psychiatry: psychotherapy, psychoanalysis, psychopharmacology, military, veterans, correctional/forensic and addictions. His philosophy of care is to do what is best for the patient. He is particularly interested in helping the underserved and members of the military. He is a member of the Colorado Psychiatric Society and the American Psychiatric Association, and a Distinguished Life Fellow in the American Psychiatric Association. Dr. Wiberg is board certified in Psychiatry by the American Board of Psychiatry and Neurology and Certified in Psychoanalysis by the American Psychoanalytic Association.

Carol Traut, M.D., is the Medical Director of the Methadone Maintenance Clinic and the program director, Addiction Psychiatry Fellowship. The opiate replacement program provides opioid replacement therapy for patients meeting specific criteria for admission. These patients receive a high level of professional support to remain free from opioids and other illicit drugs. The patient’s progress is closely monitored, and they are asked to attend group or individual sessions to receive closer supervision. Treatment includes individual and group counseling, random urine tests, individual relapse prevention plans, and case management. Dr. Traut graduated from the University of Southern California School of Medicine and completed her residency in psychiatry at the University of Colorado School of Medicine.