Department of Psychiatry

Penn Behavioral Health

Our Team

Charles O'Brien, MD, PhD

Charles O'Brien, MD, PhD

Dr. O'Brien received his MD and PhD degrees from Tulane University, and received residency training in psychiatry, neurology, and medicine at Harvard, the University of London, Tulane and the University of Pennsylvania (Penn). He is board-certified in psychiatry, neurology and addiction psychiatry.

One of the most prominent addiction researchers in the world, Dr. O'Brien has made many important discoveries and contributions over the past 30 years that have become the standard of care in addiction treatment throughout the world. Aside from developing medications to treat alcohol, opioid, and cocaine dependence, his work has also increased the understanding of the clinical aspects of addiction and the neurobiology of relapse.

Among his numerous honors, Dr. O'Brien was elected to the Institute of Medicine of the National Academy of Sciences in 1991, and received the Nathan B. Eddy award for research from the College on Problems of Drug Dependence in 2003. He has advised our national government on drug policy for decades, and was the President of the American College of Neuropsychopharmacology, and the Association for Research in Nervous and Mental Disease.

Dr. O'Brien is the Vice-Chair of Psychiatry at Penn, and the founding director of the prestigious Center for Studies of Addiction.

View Faculty Bio >

Core Staff

Marja Mattila-Evenden, MD

Marja Mattila-Evenden, MD
Medical Director

Dr. Marja Mattila-Evenden is a board-certified psychiatrist in General Psychiatry and Addiction Psychiatry.  She received her basic medical training at the University of Helsinki, Finland, where she also was active in clinical research on the psychomotor side-effects and traffic safety of psychotropic medications alone and in combinations in healthy volunteers.  She continued her career with post-doctoral studies and further clinical training at the Karolinska Institute of Clinical Neuroscience, Stockholm, Sweden.  Her research work there was in the areas of suicidology, use of psychiatric rating scale techniques in affective disorders, and psychiatric genetics.  She was employed as an Attending Psychiatrist at the Magnus Huss Clinic, a WHO center of excellence for Addiction Research and Training at the Karolinska Institute.  Dr. Mattila-Evenden completed her US residency in the Dept of Psychiatry and Behavioral Science at Temple University with a fellowship in Addiction Psychiatry at the University of Pennsylvania.

Dr. Mattila-Evenden is specially trained for medication assisted treatments for opioid dependence, and has published scientific and educational articles on benzodiazepine anxiolytics and their interactions with other psychotropic medications.

Lynne Flores, PsyD

Lynne Flores, PsyD
Licensed Clinical Psychologist

Dr. Lynne Flores received her Doctorate in Clinical Psychology from Immaculata University and her Masters degree in Psychology from Marywood University. She is licensed to independently practice psychology in the state of Pennsylvania. During her early career, she has worked with children and adolescents in individual, group, and school-based settings to reduce a variety of maladaptive behaviors utilizing Cognitive-Behavioral techniques.  Dr. Flores’s clinical doctoral training allowed her to specialize in long-term Cognitive-Behavioral Therapy with a forensic population in the Philadelphia Prison System, and comprehensive psychological assessment in an acute psychiatric inpatient population in the Philadelphia area.  She then joined the University of Pennsylvania Health System and worked in the inpatient, outpatient and assessment areas for addiction treatment utilizing group and individual therapy. Dr. Flores completed her doctoral internship and post-doctorate experience in the state of California in the Department of Developmental Services, also utilizing Cognitive-Behavioral techniques in group and individual therapy.

She has extensive experience in working with forensic populations, behavioral and substance abuse disorders, and developmental disabilities.  Dr. Flores has participated in research with the University of Pennsylvania Health System to assess the relationship of self-efficacy with cocaine abstinence, as well as research on health-related psychology topics. Since joining the Charles O'Brien Center for Addiction Treatment she has specialized in assessing and treating individuals with substance abuse disorders.

Back to Top