David Randal Hessl, Ph.D.
Clinical Interests
David Hessl's clinical interests involve cognitive, emotional, and behavioral evaluation of children,
adolescents and adults with neurodevelopmental disorders, especially those with fragile X
syndrome, autism spectrum disorders, ADHD and learning disabilities. He also has expertise in
developmental psychopathology, particularly mood and anxiety disorders, in infants and young
children.
His research focuses on genetic, environmental and hormonal contributions to cognition and
behavior in children with fragile X syndrome. He also conducts collaborative studies with other
researchers, investigating brain imaging, molecular genetics and neuropsychology in an effort to
understand links between genetics, brain function and behavior during early development.
Research/Academic Interests
Dr. David Hessl is currently the director of the Translational Psychophysiology and Assessment
Laboratory (T-PAL). 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
project examining genetics and the brain’s limbic system underlying emotional and psychiatric
symptoms in men and women with the premutation, and a longitudinal study of premutation
carriers to identify trajectories and markers of neurodegeneration..
Title
Professor
Director, Translational Psychophysiology and Assessment Center
Specialty
Clinical Psychology
David Randal Hessl, Ph.D.
Department
Division
Center/Program Affiliation
Address/Phone
Additional Phone
Psychiatry and Behavioral Sciences
Psychiatry
UC Davis MIND Institute
UC Davis MIND Institute, 2825 50th St. Sacramento, CA 95817
Phone: 916-703-0249
Physician Referrals: 800-4-UCDAVIS (800-482-3284)
Email
Education
drhessl@ucdavis.edu
Ph.D., Child Clinical Psychology and Developmental Psychology, University of Washington, Seattle
WA 1997
M.S., Child Clinical Psychology, University of Washington, Seattle WA 1995
B.A., UCLA, Los Angeles CA 1989
Internships
Lucile Packard Children's Hospital/Children's Health Council, Stanford University School of
Medicine, Stanford CA 1996-1997
Fellowships
Honors and Awards
University of California, Berkeley, Berkeley CA 1997-1998
Jarrett Cole Clinical Award, National Fragile X Foundation, for “Dedicated Service to Families in
the Worldwide Fragile X Community”, 2012
Dean’s Team Award for Excellence, U.C. Davis School of Medicine, 2009
Select Recent Publications
Cohen S, Masyn K, Mastergeorge A, %26amp%3B Hessl D. Psychophysiological responses to
emotional stimuli in children and adolescents with autism and fragile X syndrome. J of Clin Child
and Adolescent Psychology. 2015;44(2), 250-263.
Sansone SM, Schneider A, Bickel E, Berry-Kravis E, Prescott C, %26amp%3B Hessl D. Improving
IQ measurement in intellectual disabilities using true deviation from population norms. J of
Neurodevelopmental Disorders. 2014;6(16),1-14.
Wang JY, Hessl D, Schneider A, Tassone F, Hagerman RJ, %26amp%3B Rivera SM (2013). Fragile
X-associated tremor/ataxia syndrome: Influence of the FMR1 gene on motor fiber tracts in males
David Randal Hessl, Ph.D.
with normal and premutation alleles. JAMA Neurology. 2013;70(8), 1022-1029.
Sansone SM, Widaman KF, Hall SS, Reiss AL, Lightbody A, Kaufmann WE, Berry-Kravis E,
Lachiewicz A, Brown EC, %26amp%3B Hessl D. Psychometric study of the Aberrant Behavior
Checklist in fragile X syndrome and implications for targeted treatment. J of Autism and
Developmental Disorders. 2011;42(7), 1377-1392.
Hessl D, Wang JM, Schneider A, Koldewyn K, Le L, Iwahashi C, Tassone F, Hagerman PJ, %
26amp%3B Rivera SM. Deficient FMRP underlies amygdala dysfunction in carriers of the fragile X
premutation. Biological Psychiatry. 2011;70(9), 859-865.
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