Kerry J. Ressler, MD, PhD

Kerry J. Ressler, MD, PhD

McLean Hospital Title
Harvard Medical School Title
  • Professor of Psychiatry


Kerry J. Ressler, MD, PhD, is chief scientific officer and James and Patricia Poitras Chair in Psychiatry at McLean Hospital. He is also a professor in psychiatry at Harvard Medical School and past-president of the Society for Biological Psychiatry. Dr. Ressler was previously an investigator of the Howard Hughes Medical Institute and is a member of the National Academy of Medicine.

Dr. Ressler’s lab focuses on translational research bridging molecular neurobiology in animal models with human genetic research on emotion, particularly fear and anxiety disorders. He has published over 350 manuscripts ranging from basic molecular mechanisms of fear processing to understanding how emotion is encoded in a region of the brain called the amygdala, in both animal models and human patients.

Research Focus:

Dr. Ressler’s Neurobiology of Fear Laboratory, founded in 2001 at Emory University and relocated to McLean Hospital in 2015, investigates the molecular, genetic, epigenetic, and neural circuit mechanisms underlying fear processes through an integration of animal models and human genetic research. The hope is that gaining a better understanding of how fear works in the brain will contribute to the development of new treatments, and possibly even prevention, of fear-based psychiatric illnesses.

To truly understand and treat complex neuropsychiatric disorders, we need to know what behaviors are affected, which brain regions are involved, which genes, molecules, and cell types in these regions might be involved, and how the environment affects the propensity to develop these disorders. Dr. Ressler’s research encompasses these questions, with focus on fear and post-traumatic stress disorder (PTSD).

Dr. Ressler’s group uses well-established mouse models to examine different aspects of fear learning and investigate the role of different brain regions, in particular the amygdala, in fear processing. Furthermore, the lab examines how these mechanisms may be involved in the development of fear-based disorders, such as PTSD, phobic disorders, and panic disorder. Utilizing data collected from human clinical populations, Dr. Ressler and his team identify genetic traits and neural processes that may contribute to the underlying causes of these illnesses and provide novel targets for animal models research.

An important observation in recent years is that there are a number of different learning components involved in the fear response following trauma exposure and recovery. Evidence suggests that trauma exposure in the past (in particular, child abuse), prior to the current ‘index trauma’ is associated with increased risk for PTSD onset. Furthermore, twin studies suggest approximately 30-40% genetic heritability. Together these components constitute differential pre-existing sensitivity.

During the minutes to hours to days following trauma exposure, trauma memory remains in a labile state, called the consolidation period. There are many exciting areas of inquiry suggesting that new pharmacotherapeutic and psychotherapeutic approaches can be initiated that may inhibit the emotional component of fear memory consolidation, without affecting the explicit memory formation. Such an approach could prevent the severe emotional reactions that underlie later development of PTSD. There are several additional cognitive mechanisms that are associated with pathological reactions such as generalization and sensitization of trauma memory reminders. In contrast, the mechanisms of discrimination and extinction of memory serve to counter these processes. By understanding multiple different components of fear memory formation and modulation in humans and mice, a number of novel, powerful, and targeted treatment and intervention approaches may become possible.

  • Elisabeth B. Binder, MD, PhD, Max Planck Institute of Psychiatry, Munich, Germany
  • Vadim Bolshakov, PhD, McLean Hospital
  • Bekh Bradley, PhD, Emory University
  • Bill Carlezon, PhD, McLean Hospital
  • Christopher W. Cowan, PhD, Integrative Neurobiology Laboratory
  • Nikolaos P. Daskalakis, MD, PhD, McLean Hospital
  • Brian G. Dias, PhD, Emory University
  • Tanja Jovanovic, PhD, Emory University
  • Milissa Kaufman, MD, PhD, McLean Hospital
  • Torsten Klengel, MD, PhD, McLean Hospital
  • Karestan Koenen, PhD, Harvard School of Public Health
  • Charles Marmar, MD, New York University
  • Charles Nemeroff, MD, PhD, Miller School of Medicine, University of Miami
  • Donald Rainnie, PhD, Emory University
  • Barbara Rothbaum, PhD, Emory University
  • Mar Sanchez, PhD, Emory University
  • Murray Stein, MD, MPH, UCSD, San Diego VA
  • Douglas E. Williamson, PhD, University of Texas Health Science Center
Selected Publications:

Ressler KJ, Mercer KB, Bradley B, Jovanovic T, Mahan A, Kerley K, Norrholm SD, Kilaru V, Smith AK, Myers A, Ramirez M, Engel A, Hammack SE, Toufexis D, Braas KM, Binder EB, May V. Post-traumatic stress disorder is associated with PACAP and the PAC1 receptor. Nature. 2011;470(7335):492-7.

Fenster RJ, Lebois LAM, Ressler KJ, Suh J. Brain circuit dysfunction in post-traumatic stress disorder: from mouse to man. Nature Reviews Neuroscience. 2018;19(9):535-551.

Maddox SA, Hartmann J, Ross RA, Ressler KJ. Deconstructing the gestalt: mechanisms of fear, threat, and trauma memory encoding. Neuron. 2019;102(1):60-74.

PubMed search for Dr. Ressler


Book cover - Neurobiology of PTSD

Neurobiology of PTSD: From Brain to Mind
By Israel Liberzon and Kerry Ressler
(Oxford University Press, 2016)

Book cover - Anxiety Disorders

Anxiety Disorders: Translational Perspectives on Diagnosis and Treatment
by Kerry J. Ressler, Daniel S. Pine, and Barbara Olasov Rothbaum
(Oxford University Press, 2015)

Education & Training

  • 1990 BS in Molecular Biology, Massachusetts Institute of Technology
  • 1997 PhD in Neuroscience, Harvard University
  • 1997 MD, Harvard Medical School
  • 1997-1998 General Medicine Internship, Emory University School of Medicine
  • 1998-2001 Resident in Psychiatry, Emory University School of Medicine
  • 1999-2001 Research Fellow, Michael Davis Neurobiology of Fear Laboratory, Emory University
Board Certifications:
  • 1998 Medical License, State of Georgia
  • 2015 Medical License, Board of Registration in Medicine, Commonwealth of Massachusetts


Phone: 617.855.4210
Office Address: Belmont campus - Oaks Building