Intolerance of uncertainty, worry catastrophizing, and heart rate variability during worry-inducing tasks

Abstract

BackgroundReduced high frequency heart rate variability (HF-HRV) is associated with elevated worry, though considerable between-person variability has been reported. This study examined whether intolerance of uncertainty, a cognitive vulnerability for worry, predicted decreases in HF-HRV during worry-inducing tasks and whether worry catastrophizing was associated with HF-HRV. Methods76 undergraduate students completed the Intolerance of Uncertainty Scale (IUS) and had their HF-HRV monitored during resting, worry, and a Catastrophizing Interview, a task that assesses feared worry consequences. The number of consequences generated and the perceived likelihood and severity of these consequences assessed different aspects of the worry catastrophizing process. ResultsMultilevel modeling indicated that IUS scores moderated the slope of change in HF-HRV (β(E)=−.002(.001), p=0.02), whereby higher IUS scores were associated with greater decreases in HF-HRV. Regression analyses indicated that of the Catastrophizing Interview variables, only greater severity estimates were associated with lower HF-HRV during the task (β(SE)=−.07(.03), p=.02). Although IU was related to perceived severity estimates, severity estimates did not mediate the moderating impact of the IUS on changes in HF-HRV. ConclusionsIndividual differences in the extent to which people tolerate uncertainty and perceive the consequences to their worries as severe predict HF-HRV responses during worry.