David Hessl, Ph.D.

 David  Hessl, Ph.D.


  • Psychiatry and Behavioral Sciences


Translational Psychophysiology and Fragile X Syndrome

Research Summary

Dr. David Hessl is currently the director of the Translational Psychophysiology and Assessment Laboratory (T-PAL) at the UC Davis MIND Institute.  His research focuses on genetic, brain, environmental and neuroendocrine factors affecting cognition and behavior in individuals with fragile X-associated disorders. One important focus of the work in T-PAL is to develop and evaluate novel behavioral, cognitive and psychophysiological outcome measures of individuals with neurodevelopmental disorders.  These measures are designed to be used to detect improvement in functioning within controlled treatment trials.  Current psychophysiological studies have examined abnormalities in social gaze, sensorimotor gating, sympathetic nervous system activity, hypothalamic-pituitary-adrenal axis function, and potentiated startle responses.  Other recent studies have been aimed at improving aberrant behavior and cognitive measurements in individuals with fragile X syndrome, autism spectrum, intellectual disabilities, and other neurodevelopmental disorders.  A second major focus of Dr. Hessl’s work is the study of premutation carriers of fragile X.  As children these individuals are at increased risk for attention deficit hyperactivity disorder and autism and as older adults they become at risk for a neurodegenerative disease involving tremor, ataxia, and dementia.  Dr. Hessl (in collaboration with Dr. Susan Rivera) directs an NIMH-funded longitudinal study examining trajectories of brain and neuropsychological changes in men with the premutation.

Dr. Hessl earned his Ph.D. in clinical psychology from the University of Washington where his work focused on emotional and brain development in infants of depressed mothers under the supervision of Geraldine Dawson, Ph.D. He went on to a clinical internship at the Department of Psychiatry and Behavioral Sciences and the Lucile Packard Children's Hospital at Stanford University.  He also completed a MacArthur postdoctoral fellowship in psychophysiology under the supervision of W. Thomas Boyce, M.D. at the Institute of Human Development at UC Berkeley. His training continued at the Behavioral Neurogenetics Research Center at Stanford where he began his work on gene-brain-behavior studies in fragile X syndrome with Allan Reiss, M.D. He obtained an NIMH Career Development Award (K23) to examine the association between anxiety and autism symptoms in children with fragile X syndrome and the physiology underlying social anxiety problems such as gaze avoidance in these individuals.  Dr. Hessl is a licensed psychologist and his clinical interests involve cognitive, emotional, and behavioral evaluation of children, adolescents and adults with neurodevelopmental disorders, fragile X syndrome, autism spectrum disorders, ADHD, learning disabilities, and Tourette's syndrome.