Effects of experienced disgust on habituation during repeated exposure to threat-relevant stimuli in blood-injection-injury phobia.

Despite growing evidence implicating disgust in the etiology of blood-injection-injury (BII) phobia, the relevance of disgust for exposure-based treatment of BII phobia remains largely unknown. Individuals with BII phobia were randomly assigned to a disgust (view vomit videos) or neutral activation (view waterfall videos) condition. They were then exposed to 14 videotaped blood draws, during which fear and disgust levels were repeatedly assessed. Participants then engaged in a behavioral avoidance test (BAT) consisting of exposure to threat-relevant stimuli. Examination of outcome comparing the identical first and last blood-draw clips revealed that fear and disgust toward blood draws was significantly reduced in both groups. Disgust levels were also found to be more intense for the video stimuli relative to fear levels whereas the opposite was true for BAT stimuli. Contrary to predictions, the disgust induction did not enhance reductions in negative responses to the target video or reduce behavioral avoidance. Growth curve analyses did show that individuals with BII phobia exposed to the disgust induction showed greater initial fear levels during repeated exposure than those in the neutral condition. However, this effect was not consistently observed across different analytic approaches. Changes in fear during exposure were also found to be independent of changes in disgust but not vice versa, and greater initial fear levels during repeated exposure to threat was associated with fear and disgust levels during the BAT. The implications of these findings for conceptualizing the role of disgust in etiology and treatment of BII phobia are discussed.

Disgust, anxiety, and vasovagal syncope sensations: a comparison of injection-fearful and nonfearful blood donors.

Although research has implicated disgust in the fainting response observed in blood-injection-injury (BII) phobia, this finding has not been consistently observed in the literature. The present study further examines the relationship between disgust and fainting symptoms among injection-fearful (n=108) and nonfearful (n=338) blood donors. Volunteers from community blood drives provided pre-donation levels of anxiety and disgust towards giving blood and completed a standardized measure of vasovagal reactions (fainting) to blood donation after giving blood. As predicted, injection-fearful participants reported significantly more pre-donation anxiety and disgust compared to nonfearful participants. Injection-fearful donors also reported experiencing more fainting symptoms during blood donation and found the donation experience more unpleasant than did nonfearful participants. Although pre-donation disgust and anxiety levels each uniquely predicted fainting symptoms among nonfearful donors, only pre-donation anxiety uniquely predicted fainting symptoms among injection-fearful donors. Implications of these findings for conceptualizing the disgust-faint relationship in BII phobia are discussed.