Dr. Blair Wisco (Psychology) received $436,500 in new funding from the National Institutes of Health for the project “Ambulatory Physiological Assessment of Postraumatic Stress Disorder.” The abstracts states: Posttraumatic stress disorder (PTSD) affects 6.5 percent of the U.S. population, or about 21 million Americans, and tends to be chronic and impairing, representing a major public health problem. The Institute of Medicine identified exposure therapy as the front-line treatment, yet 40 percent of individuals still meet PTSD criteria following exposure therapy, indicating a need for more effective treatments. To date, PTSD treatment research has been constrained by the lack of objective measures of the theorized mechanism of action: extinction of conditioned fear to trauma cues. New assessment tools are necessary to measure this treatment target.
Conditioned fear to trauma cues is typically measured by self-report, but the UNCG team has found that self-report and physiological markers of fear responding differentially predict treatment outcome. Skin conductance (SC) is a commonly used physiological marker of fear (sympathetic arousal), but SC is not a reliable marker for a substantial minority of individuals; there is a need for new markers.
Two cardiovascular measures are particularly promising: a specific marker of sympathetic arousal (pre-ejection period, PEP), and a marker of parasympathetic withdrawal (respiratory sinus arrhythmia, RSA). The gold-standard assessment tool to measure conditioned fear in PTSD is script-driven imagery, but script-driven imagery only presents one trauma cue in one context, limiting its clinical relevance. Ambulatory physiological assessment, which measures physiological responses to events in participants’ daily lives, can measure fear responding to multiple trauma cues across different contexts, but it has yet to be tested in individuals with PTSD. The specific aims of this R15 proposal are 1) to test PEP and RSA as markers of conditioned fear to trauma cues using gold-standard script-driven imagery, and 2) to validate ambulatory physiological assessment as an objective method of measuring fear responding to trauma cues in the daily lives of individuals with PTSD.
This project represents a significant advance over existing research, including 1) assessment of new physiological markers of fear responding, 2) assessment in real-world environments, and 3) examination of different trauma cues in different contexts. This project is innovative because it will examine two novel markers of fear responding to trauma cues (PEP and RSA), and because it will test ambulatory physiological assessment as a new technique to measure trauma reactivity in PTSD.