An experimental analysis of disgust sensitivity and fear of contagion in Spider and Blood Injection Injury Phobia

Anxiety sensitivity and disgust sensitivity predict blood-injection-injury fears in individuals with dental anxiety

BACKGROUND

Anxiety sensitivity (AS) and disgust sensitivity (DS) are transdiagnostic vulnerability factors for anxiety. Both correlate with blood-injection-injury (BII) phobia symptoms in several studies; however, there is ambiguity about their relative contributions, and studies investigating this have relied on unselected samples. Furthermore, although DS reliably predicts BII in studies that do not account for AS, this may be limited to domain-specific DS rather than DS more broadly.

AIMS

The aims of this study were to examine AS and DS as separate and simultaneous predictors of BII fears in a sample with a wide range of BII symptoms, and with attention to the specificity of DS to BII-relevant domains.

METHOD

Fifty-three participants who scored above a clinical threshold on a validated measure of dental anxiety, and who represented a wide range of BII severity, completed measures of AS, DS and BII symptoms.

RESULTS

AS and DS were moderately to strongly correlated with BII severity (r = .40 and .47, p = .004 and <.001), and both independently predicted BII severity when entered as simultaneous predictors (β = .32 and .35, p = .045 and .015). Furthermore, after omitting DS about injections and blood draws, domain-general DS was still moderately correlated with BII severity (r = .33, p = .017). However, domain-general DS did not significantly predict BII severity after accounting for AS (β = .20, p = .164).

CONCLUSIONS

AS and DS both predict BII symptoms, and prospective research is warranted to examine them as potential vulnerability factors.

Fear of clowns: An investigation into the aetiology of coulrophobia

Introduction

Fear of clowns or coulrophobia is a little understood phenomenon despite studies indicating that it has a high prevalence in the general population. There have been no previous investigations into the aetiology of this fear, although several plausible hypotheses from the wider literature can be generated; the fear stems from media portrayals of scary clowns, from the unusual physical appearance or the unpredictable behaviour displayed, or it derives from an unpleasant personal experience.

Methods

The current study reviews the literature in this area and also pilots a new questionnaire (Origin of Fear of Clowns Questionnaire; OFCQ) to explore the causes of the fear of clowns in a sample of 528 participants who reported such a fear.

Results

Our findings suggest that uncertainty of harmful intent, media influences and unpredictability of behaviour play an important role in the origins of coulrophobia. There are also multiple features of clown appearance which produce a negative experiential state and a sense of a direct threat.

Discussion

We conclude that the origins of clown fear are multi-factorial and primarily relate to aspects of their facial appearance, their behaviour, and how they have been portrayed in the media. Surprisingly, fear derived from personal experience was not one of our main findings. Further research is focused on looking at associations between the level of fear and each aetiological category.

Generalization gradients for fear and disgust in human associative learning

Previous research indicates that excessive fear is a critical feature in anxiety disorders; however, recent studies suggest that disgust may also contribute to the etiology and maintenance of some anxiety disorders. It remains unclear if differences exist between these two threat-related emotions in conditioning and generalization. Evaluating different patterns of fear and disgust learning would facilitate a deeper understanding of how anxiety disorders develop. In this study, 32 college students completed threat conditioning tasks, including conditioned stimuli paired with frightening or disgusting images. Fear and disgust were divided into two randomly ordered blocks to examine differences by recording subjective US expectancy ratings and eye movements in the conditioning and generalization process. During conditioning, differing US expectancy ratings (fear vs. disgust) were found only on CS-, which may demonstrated that fear is associated with inferior discrimination learning. During the generalization test, participants exhibited greater US expectancy ratings to fear-related GS1 (generalized stimulus) and GS2 relative to disgust GS1 and GS2. Fear led to longer reaction times than disgust in both phases, and the pupil size and fixation duration for fear stimuli were larger than for disgust stimuli, suggesting that disgust generalization has a steeper gradient than fear generalization. These findings provide preliminary evidence for differences between fear- and disgust-related stimuli in conditioning and generalization, and suggest insights into treatment for anxiety and other fear- or disgust-related disorders.

The Role of Insular Cortex in Response to Group Therapy in Vaginismus Patients: Magnetic Resonance Spectroscopy Study

OBJECTIVE

Disgust has been propounded as a potential etiological factor in certain sexual dysfunctions such as vaginismus. Studies reports that insular cortex is activated as a response to disgust. The present study aimed to investigate the predictive role of metabolites in insular cortex in response to group therapy among vaginismus patients.

METHODS

Study sample consisted of 51 vaginismus patients attended an ambulatory group therapy, of whom 26 benefited from 8-week group therapy and 25 were unresponsive to group therapy. All of the patients underwent H magnetic resonance spectroscopy (H-MRS), and insular cortex N-acetyl aspartate (NAA), Creatinine (Cr), Glutamine (Gln), Glutathione (GSH), Choline (Cho), Myo-inositol (mIns), Glutamate (Glu) and Lactate (Lac) concentrations were compared between the groups.

RESULTS

Comparing insular cortex metabolite concentrations between the groups, Cho was statistically significantly higher (p=0.005) but mIns was significantly lower (p=0.001) in the unresponsive to group therapy group.

CONCLUSION

MR spectroscopy findings of the present study indicated significant metabolic changes such as increased Cho/Cr ratio and decreased mIns/Cr ratio in the insular cortex of vaginismus patients who were unresponsive to group therapy. Our results support the studies suggesting that disgust is an important emotion in vaginismus patients and also that insula plays a role in the neurobiology of disgust.

Food-Specific Inhibitory Control Mediates the Effect of Disgust Sensitivity on Body Mass Index

Disgust is an emotion that drives food avoidance. People vary in their responses to disgust, which is captured by their disgust sensitivity. Disgust sensitivity is clinically significant because it can influence eating behaviors, and indirectly people's body mass index (BMI). Inhibitory control can also influence BMI through the role that such reflective abilities play in governing food intake. In this study, we relied on neural models of disgust to suggest that disgust and inhibitory control are intertwined, and that inhibitory control facilitates the translation of disgust sensitivity into BMI. Mediation analyses applied to 46 subjects, including 29 normal body weight [BMI = 18.34 kg/m² (SD = 1.58)] and 17 overweight/obese [BMI = 26.03 kg/m² (SD = 2.58)] subjects, were used to test the hypothesis. Subjects completed the Chinese version of the Disgust Scale-Revised, and an inhibition control test (Food-Specific Stop-Signal Task). There were negative correlations between the disgust sensitivity score (DS) and body mass index (BMI), and between DS and stop-signal reaction time (SSRT). Moreover, BMI was positively correlated with SSRT. The mediation model results showed that disgust sensitivity was associated with BMI and that this relationship was mediated via inhibition control. There was no significant effect of DS on BMI, while the effect of SSRT on BMI was significant. This suggested that the effect of disgust sensitivity on BMI was fully mediated through food-specific inhibitory control. This supports our hypothesis that BMI is affected by disgust sensitivity and that this relationship is mediated by inhibition control. These findings reveal a key mechanism that underlies disgust sensitivity-BMI association and point to future research and potential interventions aimed at food intake management.

Is Disgust Proneness Associated With Anxiety and Related Disorders? A Qualitative Review and Meta-Analysis of Group Comparison and Correlational Studies

Research suggests that disgust may be linked to the etiology of some anxiety-related disorders. The present investigation reviews this literature and employs separate meta-analyses of clinical group comparison and correlational studies to examine the association between disgust proneness and anxiety-related disorder symptoms. Meta-analysis of 43 group comparison studies revealed those high in anxiety disorder symptoms reported significantly more disgust proneness than those low in anxiety symptoms. Although this effect was not moderated by clinical versus analogue studies or type of disorder, larger group differences were observed for those high in anxiety symptoms associated with contagion concerns compared to those high in anxiety symptoms not associated with contagion concerns. Similarly, meta-analysis of correlational data across 83 samples revealed moderate associations between disgust proneness and anxiety-related disorder symptoms. Moderator analysis revealed that the association between disgust proneness and anxiety-related disorder symptoms was especially robust for anxiety symptoms associated with contagion concerns. After controlling for measures of negative affect, disgust proneness continued to be moderately correlated with anxiety-related disorder symptoms. However, negative affect was no longer significantly associated with symptoms of anxiety-related disorders when controlling for disgust proneness. The implications of these findings are discussed in the context of a novel transdiagnostic model.

Pure animal phobia is more specific than other specific phobias: epidemiological evidence from the Zurich Study, the ZInEP and the PsyCoLaus

Interest in subtypes of mental disorders is growing in parallel with continuing research progress in psychiatry. The aim of this study was to examine pure animal phobia in contrast to other specific phobias and a mixed subtype. Data from three representative Swiss community samples were analysed: PsyCoLaus (n = 3720), the ZInEP Epidemiology Survey (n = 1500) and the Zurich Study (n = 591). Pure animal phobia and mixed animal/other specific phobias consistently displayed a low age at onset of first symptoms (8-12 years) and clear preponderance of females (OR > 3). Meanwhile, other specific phobias started up to 10 years later and displayed almost a balanced sex ratio. Pure animal phobia showed no associations with any included risk factors and comorbid disorders, in contrast to numerous associations found in the mixed subtype and in other specific phobias. Across the whole range of epidemiological parameters examined in three different samples, pure animal phobia seems to represent a different entity compared to other specific phobias. The etiopathogenetic mechanisms and risk factors associated with pure animal phobias appear less clear than ever.

Brain processing of visual stimuli representing sexual penetration versus core and animal-reminder disgust in women with lifelong vaginismus

It has been proposed that disgust evolved to protect humans from contamination. Through eliciting the overwhelming urge to withdraw from the disgusting stimuli, it would facilitate avoidance of contact with pathogens. The physical proximity implied in sexual intercourse provides ample opportunity for contamination and may thus set the stage for eliciting pathogen disgust. Building on this, it has been argued that the involuntary muscle contraction characteristic of vaginismus (i.e., inability to have vaginal penetration) may be elicited by the prospect of penetration by potential contaminants. To further investigate this disgust-based interpretation of vaginismus (in DSM-5 classified as a Genito-Pelvic Pain/Penetration Disorder, GPPPD) we used functional magnetic resonance imaging (fMRI) to examine if women with vaginismus (n = 21) show relatively strong convergence in their brain responses towards sexual penetration- and disgust-related pictures compared to sexually asymptomatic women (n = 21) and women suffering from vulvar pain (dyspareunia/also classified as GPPPD in the DSM-5, n = 21). At the subjective level, both clinical groups rated penetration stimuli as more disgusting than asymptomatic women. However, the brain responses to penetration stimuli did not differ between groups. In addition, there was considerable conjoint brain activity in response to penetration and disgust pictures, which yield for both animal-reminder (e.g., mutilation) and core (e.g., rotten food) disgust domains. However, this overlap in brain activation was similar for all groups. A possible explanation for the lack of vaginismus-specific brain responses lies in the alleged female ambiguity (procreation/pleasure vs. contamination/disgust) toward penetration: generally in women a (default) disgust response tendency may prevail in the absence of sexual readiness. Accordingly, a critical next step would be to examine the processing of penetration stimuli following the induction of sexual arousal.