Effects of repeated exposure to fearful and disgusting stimuli on fear renewal in blood-injection-injury phobia

Abstract

Although exposure is effective for blood-injection-injury (BII) phobia, fear often returns after treatment. While disgust has been implicated in BII phobia, its effects on fear renewal are unclear. To address this knowledge gap, the present study examined the effect of repeated video exposure to fearful and disgusting stimuli in multiple contexts on fear renewal in BII phobia. Individuals with BII phobia (N = 57) were randomized to Disgust-Specific Exposure (DSE) which included exposure to disgusting but threat-irrelevant stimuli (i.e., vomit), Fear-Specific Exposure (FSE) which included exposure to threat-relevant stimuli (i.e., injections), or General Negative Exposure (GNE) which included exposure designed to elicit negative affect (i.e., tornado) without being disgusting or threat-relevant. During session one, participants watched a pre- and post-exposure assessment injection video (“pre/post assessment”), and a novel injection video after exposure to assess renewal effects (“novel 1”). Participants came in one week later to rate the same videos, and a new injection video (“novel 2”). For week one outcomes, comparisons of covariate adjusted means indicated the fear-specific group reported significantly lower levels of anxiety than the general-negative group to the post-exposure and novel 1 stimulus. When presented with the post-exposure stimuli during week two, the disgust-specific and fear-specific groups reported significantly lower levels of anxiety than the general negative group. The fear-specific group also reported significantly lower levels of anxiety than the disgust-specific and general-negative groups when presented with novel 1 and novel 2 stimuli at week two. These findings suggest that repeated exposure to threat-relevant cues in multiple contexts does reduce the return of anxiety. However, repeated exposure to disgusting but threat irrelevant stimuli may also produce some therapeutic effects. The implications of the integration of disgust-relevant processes into exposure-based treatment of BII phobia are discussed.