PROJECT SUMMARY/ABSTRACT
Anxiety is a common and impairing psychiatric comorbidity affecting up to 70% of youth with autism spectrum
disorder (ASD) for which there are very limited evidence-based treatments. Gold-standard treatment approaches
including selective serotonin reuptake inhibitors (SSRIs) and cognitive behavioral therapy (CBT) are often
unsuitable, ineffective, or poorly tolerated in youth with ASD. No large scale, well-powered clinical trials of
pharmacotherapy for anxiety in ASD have been published. Prior research on anxiety in ASD has key
methodological limitations including the lack of high quality clinical endpoints, objective biomarkers, or known
mechanisms underlying treatment response. Our long-term goal is to advance the evidence-based treatment for
anxiety in youth with ASD by identifying underlying treatment mechanisms and conducting high quality clinical
trials. The objectives of this proposal are to (1) identify autonomic nervous system (ANS) measures that can be
obtained in youth with ASD which correlate with anxiety severity in the K99 phase (Aim 1) and (2) to conduct a
randomized controlled trial of buspirone to preliminarily assess its efficacy (Aim 2) and whether ANS modulation
is a target mechanism (Aim 3) in the R00 phase. This contribution is significant since youth with ASD commonly
experience anxiety disorders and there are limited evidence-based treatments. The proposed research is
innovative in that it will be the first ASD clinical trial to incorporate objective physiologic mechanisms, decreasing
overreliance on subject self-/parent-report or clinician rating. Aims of the principal investigator’s K99 career
development and training plan include (1) Obtain training and applied experience acquiring and interpreting
autonomic nervous system (psychophysiology) data in youth with ASD, (2) Develop expertise in
psychopharmacology clinical trials design and execution, (3) Develop familiarity with applied biostatistics relevant
to intervention trials, and (4) Advance skills in manuscript preparation, grantsmanship, leadership, and
responsible conduct of research. These goals will be achieved through a training plan comprised of mentorship,
formal coursework, conferences, and manuscript/grant preparation. Knowledge gained via the training plan will
be augmented by the applied research experience. Drs. Christopher McDougle, Kerry Ressler, Sabine Wilhelm,
David Eddie, and Caitlin Ravichandran will serve as mentors on this award. Massachusetts General Hospital-
Harvard Medical School provides an exceptional environment in which to conduct this training and research. By
the end of the R00 period, the principal investigator will have a working methodology for obtaining ANS measures
relevant to clinical trials in youth with ASD and anxiety, a preliminary estimate of the placebo effect and
buspirone-placebo difference, and sample size needed to more fully test physiologic mechanisms. These will
inform a multi-site R01 effectiveness trial of buspirone or other anti-anxiety medications. The principal
investigator will also have the training and experience needed to successfully obtain R61/R33 funding to test
novel agents that are either in active development or repurposed non-CNS agents for anxiety in this population.