Office of the DER Director

What We Do:

Provide leadership and oversight for NIDA’s extramural programs, including extramural policy and scientific review, grants management, operations planning, and trans-NIH initiatives.


  • Susan Weiss, Ph.D. - Director
    Dr. Weiss is the Director of the Division of Extramural Research (DER) at the National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH); which, oversees NIDA’s extramural programs, research training, operations planning, and trans-NIH initiatives, such as the Collaborative Research on Addiction at NIH (CRAN) and the Adolescent Brain Cognitive Development (ABCD) study. Dr. Weiss is also a Senior Science Advisor to the NIDA Director. Previously, she served as the Chief of the Science Policy Branch and Acting Director of NIDA's Office of Science Policy and Communications, where she provided leadership and oversight for all of NIDA’s interactions with its diverse stakeholders. Read a more detailed biography
  • Katia Howlett, Ph.D., M.P.P., M.B.A. - Deputy Director
    Dr. Howlett joined the Division of Extramural Research (DER) at the National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH) in 2015. In addition to her role in DER as Deputy Director, she serves as the NIDA Clinical Trials Stewardship Policies Implementation Coordinator and Risk Manager. Prior to joining NIDA, she served as the Project Director of the NIDA Blending Initiative contract and the SAMHSA National Campaigns contract with Synergy Enterprises, Inc. Prior to that, she served as Deputy Director of the SAMHSA Underage Drinking Prevention Education Initiatives contract with University Research Company, LLC. In these roles, Dr. Howlett managed the development of evidence-based national educational trainings, materials, resources, and campaigns for researchers, healthcare professionals, children, adolescents, and families to promote the prevention of substance use disorders and the implementation of evidenced-based practices in the treatment of these illnesses in healthcare settings. Dr. Howlett received a Ph.D. in Public Health from the University of California at San Diego and San Diego State University, Master of Public Policy from Pepperdine University, and Master of Business Administration from the Johns Hopkins University. Her doctoral training in Public Health focused on health behavior and the prevention of risky behaviors including primary prevention of Fetal Alcohol Spectrum Disorders and other consequences of alcohol misuse. She has expertise in the fields of mental health, public health and safety, health policy, health communication, and substance abuse and addiction. She is widely published in the fields of mental illness and substance use disorders, on topics as varied as adolescent substance abuse, technology-based health interventions, mood and anxiety disorders, and health-related quality of life.
  • Troy Zarcone, Ph.D. - Special Advisor
    Dr. Zarcone is a Special Advisor to the Director of NIDA’s Division of Extramural Research. He has extensive experience in monitoring, analyzing, and reporting on information and issues impacting NIH research. He conducts portfolio analyses and evaluations of research and participates on trans-NIH committees. Before joining NIDA, Dr. Zarcone was a Health Science Administration at NIAAA where he also served as the Editor-in-Chief of NIAAA’s peer-reviewed journal, Alcohol Research: Current Reviews. Before that, Dr. Zarcone was an Associate Research Professor at the University of Rochester Medical Center where he also served as the Scientific Director of the NeuroBehavioral Core Facility.   
  • Carolyn Tucker - Administrative Technician
    Mrs. Tucker has over a decade of experience as an Extramural Support Assistant at NIDA.  She joined the Division of Extramural Research (DER) and the ABCD Project in October 2015. Mrs. Tucker has assisted in the coordination of division and institution workgroups as well as logistical and planning operations.  Her academic experience includes coursework in applied sciences at the University of the District of Columbia and additional training in Project Management.  She is a proud parent advocate for children with special needs and serves as the Secretary for the Parents of Children with Down syndrome of Prince George’s County in Maryland.

Office of Trans-NIH Initiatives

Adolescent Brain Cognitive Development (ABCD) Project

  • Gayathri J. Dowling, Ph.D. - Director (ABCD Project)
    Dr. Dowling is the Director of the Adolescent Brain and Cognitive Development (ABCD) Project at the National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH). The ABCD Study is the largest long-term study of brain development and child health in the United States. Partnering with educators and parents, scientists with the ABCD study will recruit 10,000 children at age 9-10 and follow them through their teens and into early adulthood to explore how diverse experiences during adolescence shape brain, cognitive, social, emotional, and academic development. Previously, Dr. Dowling served as the Deputy Director of the Office of Science Policy, Engagement, Education, and Communications at the National Heart, Lung, and Blood Institute and the Chief of Science Policy at NIDA. In these positions, she provided scientifically-based information to patients and their family members, health professionals, researchers, policy makers, and other stakeholders to inform policy and promote the prevention and treatment of a wide variety of diseases. She has also served as a Program Director with the National Institute of Neurological Disorders and Stroke and as a Scientific Review Administrator at the National Institute of Mental Health. Dr. Dowling earned a Ph.D. in Neurobiology from the University of California at Davis, where she studied the developing nervous system, and subsequently conducted research at the Parkinson’s Institute. Along with publishing multiple scientific papers and a range of multimedia products, Dr. Dowling has earned numerous awards and widespread recognition for her work.
  • Elizabeth Hoffman, Ph.D. - Scientific Program Manager (ABCD Project)
    Dr. Hoffman joined the Division of Extramural Research (DER) at the National Institute on Drug Abuse (NIDA) in 2016 as Scientific Program Manager for the Adolescent Brain Cognitive Development (ABCD) Study. Prior to joining the ABCD team, Dr. Hoffman conducted functional MRI research on face perception in the Intramural Program at NIMH, taught psychology and cognitive neuroscience at a number of institutions, and advocated for science and health policy priorities in the U.S. Senate and at the American Psychological Association. Dr. Hoffman holds a Ph.D. in cognitive neuropsychology from the George Washington University.
  • Kimberly LeBlanc, Ph.D. - Scientific Program Manager (ABCD Project)
    Dr. LeBlanc joined the Division of Extramural Research (DER) at the National Institute on Drug Abuse (NIDA), National Institutes of Health (NIH) in 2018 as Scientific Program Manager for the Adolescent Brain Cognitive Development (ABCD) Study.  She is a behavioral neuroscientist with experience in data science, having competed in the HHS opioid code-a-thon and two NIH hack-a-thons. She comes to NIDA from the Scientific Review Branch of National Institute on Aging. Previously, she completed a tour as a Visiting Bioinformatician at the National Center for Biotechnology Information as well as a detail as a Program Officer in the Division of Neuroscience and Behavior at NIDA.  Dr. LeBlanc performed postdoctoral training at the National Institute of Diabetes, Digestive and Kidney Diseases, and earned her Ph.D. in Neuroscience from the University of California, Los Angeles,  where her research focused on the impact of cocaine on habitual control and incentive sensitization in animal models of drug taking.

HEALthy Brain Child Development (HEALthy BCD) Project​

  • Michelle Freund, Ph.D. - Director (HBCD Project)
    Dr. Freund joined NIDA in January and will serve as the Project Director for the HEALthy Brain Child Development (HEALthy BCD) Study. She comes to NIDA from the Office of Technology Development and Coordination at the National Institute of Mental Health where she managed a research portfolio of grants that are focused on the development of novel tools and technologies important for the advancement of basic and translational neuroscience.  Michelle served as the Director for the NIH NeuroBioBank, a network of six brain and tissue repositories that provide post-mortem human brain samples for research, and has been an active member of several trans-NIH interdisciplinary teams such as the NIH BRAIN Initiative and the Blueprint for Neuroscience.  As co-lead on a BRAIN Initiative team, she provided guidance and oversight for the Cells and Circuits focus area outlined in the BRAIN 2025 report.  Michelle received a B.A. from the University of California, San Diego in mammalian physiology and a Ph.D. in Neuroscience from Hahnemann University in Philadelphia.   Before joining NIH in 2007, she studied the role of monoamine neurotransmitters in the actions of antidepressant drugs and the interactions of stress and drug addiction.