Multimodal assessment of disgust in contamination-related obsessive-compulsive disorder

Is disgust associated with psychopathology? Emerging research in the anxiety disorders

Recent evidence indicates that the propensity towards experiencing disgust may contribute to the development and maintenance of some anxiety disorders. This article summarizes the empirical evidence with emphasis on illuminating potential mediators, moderators, and mechanisms of the disgust-anxiety disorder association that may inform the development of an integrative conceptual model. Early research using neuroimaging methods suggest that disgust processing is associated with activation of the insula. This research has the potential to facilitate progress in developing an empirically informed psychobiological theory on the causal role of disgust in the anxiety disorders.

Orienting and maintenance of gaze in contamination fear: Biases for disgust and fear cues

The present study examines the extent to which attentional biases in contamination fear commonly observed in obsessive-compulsive disorder (OCD) are specific to disgust or fear cues, as well as the components of attention involved. Eye tracking was used to provide greater sensitivity and specificity than afforded by traditional reaction time measures of attention. Participants high (HCF; n = 23) and low (LCF; n = 25) in contamination fear were presented with disgusted, fearful, or happy faces paired with neutral faces for 3 s trials. Evidence of both vigilance and maintenance-based biases for threat was found. The high group oriented attention to fearful faces but not disgusted faces compared to the low group. However, the high group maintained attention on both disgusted and fearful expressions compared to the low group, a pattern consistent across the 3 s trials. The implications of these findings for conceptualizing emotional factors that moderate attentional biases in contamination-based OCD are discussed.

Components of attentional biases in contamination fear: evidence for difficulty in disengagement

Attentional bias for threat has been implicated in the contamination fear (CF) subtype of obsessive-compulsive disorder, but the components of the bias (facilitated attention versus difficulty in disengagement) and the stage of processing during which the bias occurs (early versus late stage of processing) remains unclear. Further, it is unclear whether attentional biases in CF are towards fear or disgust-related stimuli. The present study examined attentional biases in a group of individuals selected to have elevated CF (n = 23) and a control group (n = 28) using the spatial cueing task. Stimuli were neutral, disgusting, or frightening pictures presented for either 100 or 500 ms. Results revealed evidence for delayed disengagement from both fear and disgust stimuli in the CF group, but not in the control group. The effect appeared to be greater at 500 ms stimulus presentation, but did not appear to differ between fear and disgust stimuli. The CF group was associated with delayed disengagement from threat even when controlling for generic response slowing. Theoretical and clinical implications are discussed.

Cognitive bias to symptom and obsessive belief threat cues in obsessive-compulsive disorder

The current study examined the extent to which patients with obsessive compulsive disorder (OCD) demonstrate cognitive biases to OCD symptom or inflated responsibility threat cues. Participants with either primary contamination-washing or doubting/harming-checking OCD, non-OCD anxiety disorders, and student controls completed a primed lexical decision task. Following either neutral or OCD-threat priming conditions, participants made lexical decisions regarding different sets of word stimuli: nonwords, OCD symptoms, OCD inflated responsibility, and depression. Following the OCD primes, the primary contamination-washing symptom subgroup showed increased interference on OCD symptom words compared with the harming symptom and student groups. The primary contamination-washing subgroup also showed increased interference on responsibility words compared with the harming, non-OCD anxious and student groups. However, subsidiary analyses comparing patients with contamination obsessions with and without associated fears of harming others through the spreading of contaminants, demonstrated that it was the latter group that evidenced cognitive biases to responsibility threat cues. These results are considered in relation to cognitive models of OCD.

Incremental specificity of disgust propensity and sensitivity in the prediction of health anxiety dimensions

The present study sought to determine the incremental specificity of disgust propensity and sensitivity in the prediction of symptoms of health anxiety in a large nonclinical sample (N=498). Exploratory factor analysis identified Illness Likelihood, Illness Severity, and Body Vigilance as dimensions of health anxiety symptoms that significantly correlated with disgust propensity and sensitivity. Negative affect and the fear of contamination were also significantly correlated with the three health anxiety symptom dimensions. Regression analyses did show that disgust propensity and sensitivity predicted overall health anxiety symptoms independent of negative affect and fear of contamination. However, the unique association between disgust propensity and sensitivity and symptoms of health anxiety was specific to the Body Vigilance dimension. These findings suggest that disgust propensity and sensitivity may be a unique vulnerability for the vigilance for bodily sensations/changes aspect of health anxiety but not necessarily other (perceived probability/severity of having a serious illness) aspects of health anxiety. The clinical and research implications of these findings for conceptualizing disgust propensity and sensitivity as a vulnerability for excessive health anxiety are discussed.

Disgust sensitivity and emotion regulation potentiate the effect of disgust propensity on spider fear, blood-injection-injury fear, and contamination fear

Research consistently reveals a relation between disgust and specific anxiety concerns, but research has only begun to investigate possible mechanisms by which this relation occurs. The current study tested whether disgust sensitivity (DS; a specific difficulty regulating disgust) and general emotion dysregulation (GED; non-emotion-specific regulation difficulties) moderated the relation between disgust propensity (DP) and spider fear, blood-injection-injury (BII) fear, and contamination fear. A total of 594 undergraduate students completed verbal-report measures of DP, DS, GED, negative affectivity, and spider, BII, and contamination fears. Results suggest that GED potentiates the ability of DP to predict spider and contamination fears, but not BII fears. DS potentiates the ability of DP to predict BII fears, but not spider or contamination fears. These data suggest that GED and DS are possible mechanisms that strengthen the influence of DP on spider, BII, and contamination fears. The present study demonstrates the utility of incorporating emotion regulation into the theory of disgust in certain anxiety disorders.

Disgust and Obsessive Beliefs in Contamination-related OCD

A large body of evidence suggests that disgust is an important affective process underlying contamination fear. An independent line of research demonstrates that obsessive beliefs, particularly overestimations of threat, are also an important cognitive process underlying contamination fear. The present study attempts to integrate these two lines of research by testing whether obsessive beliefs potentiate the influence of disgust propensity on contamination fear. The interaction between disgust propensity and obsessive beliefs was tested in two large non-clinical samples (N = 252 in Study 1; N = 308 in Study 2) using two different self-report measures of contamination fear. Regression analyses supported the hypotheses in both samples. The interaction remained significant when controlling for negative affect. The results are hypothesized to suggest that contamination fear results, at least partly, from obsessive beliefs about the contamination-based appraisals that accompany heightened disgust responding. These results complement previous affective-driven explanations of the role of disgust in contamination fear by suggesting cognitive factors that similarly potentiate disgust's role in contamination fear.

Confirming the Three-Factor Structure of the Disgust Scale—Revised in Eight Countries

The current study evaluates the factor structure of the Disgust Scale—Revised (DS-R) in eight countries: Australia, Brazil, Germany, Italy, Japan, the Netherlands, Sweden, and the United States ( N = 2,606). Confirmatory factor analysis is used to compare two different models of the DS-R and to investigate the invariance of the factor structure of the DS-R across countries and gender. A three-factor solution consisting of three different but interrelated disgust factors (a 12-item core disgust factor, an 8-item animal-reminder disgust factor, and a 5-item contamination disgust factor) best accounted for the data in all countries except the Netherlands. Relative to the United States, the three-factor solution is invariant in Australia, Brazil, and Japan but not in Germany, Italy, the Netherlands, and Sweden. The three-factor solution is also invariant across gender in most countries. The implications of these cross-cultural findings for promoting a more valid and reliable assessment of disgust dimensions, as assessed by the DS-R, are discussed.

Differential habituation of fear and disgust during repeated exposure to threat-relevant stimuli in contamination-based OCD: an analogue study

In the present study, participants (N=20) displaying marked contamination concerns were provided 30 min of repeated in vivo exposure to threat-relevant stimuli (cleaning a 'dirty' bed pan), during which time their fear and disgust levels were repeatedly assessed. Results indicated that repeated exposure led to a significant decline in fear but not disgust. The observed decline in fear remained significant after accounting for changes in disgust and vice versa. Although initial disgust was higher than initial fear ratings, differences between the two slopes were not statistically significant. Baseline trait anxiety and global disgust sensitivity levels prior to exposure did not moderate the level of fear or disgust activation during exposure. However, sensitivity specifically related to core and contamination disgust was marginally associated with fear and disgust parameters during outcome. There was also evidence that less fear decline during repeated exposure was associated with higher disgust ratings after the exposure was completed. Theoretical and clinical implications of the present findings for the treatment of contamination concerns in obsessive-compulsive disorder are discussed.

Information processing in contamination fear: a covariation bias examination of fear and disgust

The current study represents the first examination of covariation biases in contamination fear. Using an undergraduate sample we examined covariation bias for specific emotion outcomes (fear specific and disgust specific) associated with contamination stimuli in high contamination fear (HCF; n=32) and low contamination fear (LCF; n=30) individuals. Following random stimulus-outcome presentation participants provided estimations on the proportion of each presented stimulus-expression pairing. Analyses revealed a specific bias for the over-estimation of fear and disgust contingencies among the HCF group, but not the LCF group. The current study also revealed a specific covariation bias among HCF, not LCF, participants to over-estimate the contingency between contamination stimuli and fear outcomes, not disgust outcomes. Further, results indicate that HCF individuals significantly under-estimate the covariation among contamination stimuli and safety outcomes compared to LCF participants. These findings are discussed in terms of theoretical implications for information processing biases in anxiety disorders.

Trait-disgust vs. fear of contamination and the judgmental bias of contamination concerns

Mechanisms by which trait-disgust, i.e. relatively stable individual differences in disgust proneness, affects anxious psychopathology are not well understood. A possible pathway might be the impact of trait-disgust on cognitive processes, which are involved in the anxiety disorders. The present study extends findings on interpretational and attentional bias by investigating the judgmental bias. Based on theories on disgust, it was assumed that trait-disgust is related to predictions of catching a disease. The present study examined the likelihood of becoming ill, the probability of avoidance behaviour, and the urge to wash in relation to disgust-sensitivity, disgust propensity, fear of contamination, and general anxiety using real-life scenarios. Results suggest that disgust-sensitivity makes a unique contribution to a judgmental bias additionally to fear of contamination and even when controlling general anxiety. Future research concerning the causal direction of this bias is warranted.

Disgust, fear, and the anxiety disorders: a critical review

Anxiety disorders have traditionally been conceptualized as reflecting the emotions of fear and anxiety. A developing program of research demonstrates a relation between disgust and three specific anxiety disorders: blood-injection-injury (BII) phobia, spider phobia, and contamination-related obsessive-compulsive disorder (OCD). This review serves three purposes. First, the authors review the response patterns predicted to be observed if the emotional response in these disorders involved disgust versus fear. The review suggests specific response patterns that characterize disgust and fear in the domains of heart rate, facial expression, neural activity, and cognitive processes. Second, the authors review extant research employing measures of these domains in spider phobia, BII phobia, and contamination-related OCD. The evidence suggests that both fear and disgust characterize each of these disorders, but the magnitude at which the emotions characterize the disorders may depend on the response domain measured. For example, disgust may be more involved in spider phobia in appraisals and facial expression, but less involved in neural correlates or heart rate domains. Third, the authors suggest guidelines for future research, including concurrent use of specific measures as well as examining whether the different emotions in different response domains respond to similar interventions (e.g., exposure).

Individual differences in disgust sensitivity modulate neural responses to aversive/disgusting stimuli

Little is known about how individual differences in trait disgust sensitivity modulate the neural responses to disgusting stimuli in the brain. Thirty-seven adult healthy volunteers completed the Disgust Scale (DS) and viewed alternating blocks of disgusting and neutral pictures from the International Affective Picture System while undergoing fMRI scanning. DS scores correlated positively with activations in brain regions previously associated with disgust (anterior insula, ventrolateral prefrontal cortex-temporal pole, putamen-globus pallidus, dorsal anterior cingulate, and visual cortex) and negatively with brain regions involved in the regulation of emotions (dorsolateral and rostral prefrontal cortices). The results were not confounded by biological sex, anxiety or depression scores, which were statistically controlled for. Disgust sensitivity, a behavioral trait that is normally distributed in the general population, predicts the magnitude of the individual's neural responses to a broad range of disgusting stimuli. The results have implications for disgust-related psychiatric disorders.

Specificity of emotional maintenance processes among contamination fears and blood-injection-injury fears

Research evidence consistently demonstrates a relation between disgust and anxiety-related pathology. Despite ample evidence implicating a functional role of disgust in anxiety, limited research has focused on the process by which disgust influences anxiety. Recent evidence indicates that fear of responding with disgust predicts contamination fears, thus elucidating a process by which disgust contributes to contamination fears. In the current study, we tested whether fear of responding with disgust is specific to contamination fears or generalizes to blood-injection-injury (BII) fears. Undergraduate psychology students (N=259) completed measures of anxiety sensitivity (AS), trait anxiety, disgust, contamination fears, and BII fears. Data analysis revealed main effects of both AS and disgust in predicting both contamination and BII fears. The interaction between AS and disgust (i.e., being fearful of responding with disgust), however, predicted only contamination fears and not BII fears. The results suggest that fear of responding with disgust is a unique maintenance process specific to contamination fears. Theoretical and clinical implications for both contamination and BII fears are discussed.

Specificity of disgust sensitivity in the prediction of fear and disgust responding to a brief spider exposure

This study examined the specificity of disgust sensitivity in predicting fear and disgust responses to exposure to a spider. Participants high (n=22) and low (n=28) in spider fear completed self-report measures of disgust sensitivity, contamination fear, anxiety, and negative affect. They then participated in a behavioral avoidance task (BAT) in which they were briefly exposed to a realistic-looking, but fake, tarantula. Results revealed that disgust sensitivity was associated with fear and disgust responding to the BAT. The association between disgust sensitivity and disgust responding to the BAT remained significant after controlling for gender, spider fear group membership, contamination fear, anxiety, and negative affect. However, the association between disgust sensitivity and fear responding to the BAT was only marginally significant after controlling for the same variables. Contamination fear was also strongly related to fear and disgust responding to the BAT. However, this relationship was fully mediated by disgust sensitivity. These findings indicate that disgust sensitivity has a unique association with aversive responding to spiders. The implications of these findings for better understanding the complex role of fear and disgust as they related to disgust sensitivity in spider phobia are discussed.

The Disgust Propensity and Sensitivity Scale-Revised: psychometric properties and specificity in relation to anxiety disorder symptoms

The present study examined the factor structure and psychometric properties of the Disgust Propensity and Sensitivity Scale-Revised (DPSS-R) in a nonclinical sample (N=340). Principal components analysis of the DPSS-R revealed a two-factor structure consisting of Disgust Propensity and Disgust Sensitivity. Although the two-factor structure converged well with prior research, four of the 16 DPSS-R items did not load onto the predicted factor. The DPSS-R demonstrated good reliability and validity. The DPSS-R and its two factors were moderately correlated with spider fear and contamination fear and mildly correlated with injection fear. The relation between the DPSS-R and these anxiety disorder symptoms remained largely intact after controlling for negative affect. Regression analyses also revealed that the two DPSS-R factors demonstrate specificity in the prediction of anxiety disorder symptoms. These findings are discussed in terms of promoting a more valid and reliable assessment of disgust in anxiety disorders.

Sex differences in neural responses to disgusting visual stimuli: implications for disgust-related psychiatric disorders

BACKGROUND

A majority of patients with disgust-related psychiatric disorders such as animal phobias and contamination-related obsessive-compulsive disorder are women. The aim of this functional magnetic resonance imaging (fMRI) study was to examine possible sex differences in neural responses to disgust-inducing stimuli that might help explain this female predominance.

METHODS

Thirty-four healthy adult volunteers (17 women, all right-handed) were scanned while viewing alternating blocks of disgusting and neutral pictures from the International Affective Picture System. Using a partially-silent fMRI sequence, the participants rated their level of discomfort after each block of pictures. Skin conductance responses (SCR) were measured throughout the experiment. All participants completed the Disgust Scale.

RESULTS

Both women and men reported greater subjective discomfort and showed more SCR fluctuations during the disgusting picture blocks than during the neutral picture blocks. Women and men also demonstrated a similar pattern of brain response to disgusting compared with neutral pictures, showing activation in the anterior insula, ventrolateral and dorsolateral prefrontal cortices, and visual regions. Compared with men, women had significantly higher disgust sensitivity scores, experienced more subjective discomfort, and demonstrated greater activity in left ventrolateral prefrontal regions. However, these differences were no longer significant when disgust sensitivity scores were controlled for.

CONCLUSIONS

In healthy adult volunteers, there are significant sex-related differences in brain responses to disgusting stimuli that are irrevocably linked to greater disgust sensitivity scores in women. The implications for disgust-related psychiatric disorders are discussed.

Structural differentiation of disgust from trait anxiety in the prediction of specific anxiety disorder symptoms

Research has begun to implicate the role of disgust in the etiology of specific phobias and obsessive-compulsive disorder (OCD). However, it remains unclear if the association between disgust and specific anxiety disorder symptoms is an artifact of trait anxiety or a potential mechanism through which trait anxiety effects specific anxiety disorder symptoms. The present study employed structural equation modeling to differentiate disgust from trait anxiety in the prediction of four types of specific anxiety disorder symptoms in a non-clinical sample (N=352). Results indicate that disgust and trait anxiety latent factors were independently related to spider fears, blood-injection-injury (BII) fears, general OCD symptoms, and OCD washing concerns. However, when both variables were simultaneously modeled as predictors, latent disgust remained significantly associated with the anxiety disorder symptoms, whereas the association between latent trait anxiety and the anxiety disorder symptoms became non-significant or was substantially reduced. Statistical tests of intervening variable effects converged in support of disgust as a significant intervening variable between trait anxiety and spider fears, BII fears, and OCD symptoms (particularly washing concerns). The relevance of these findings for future research investigating the role of disgust in specific anxiety disorders is discussed.

Disgust and psychiatric illness: have we remembered?

It has been argued that disgust has been forgotten by psychiatry. An overview of recent research on disgust is provided. Findings suggest that disgust is a predictor of the development of specific psychiatric conditions.

Specificity of disgust sensitivity in the prediction of behavioral avoidance in contamination fear

This study examined the specificity of disgust sensitivity in predicting contamination-related anxiety and behavioral avoidance. Participants high (n=26) and low (n=30) in contamination fear completed self-report measures of disgust sensitivity, contamination cognitions (overestimation of the likelihood and severity of contamination from everyday objects), anxiety, and depression. They then completed three randomly presented contamination-based behavioral avoidance tasks (BATs) that consisted of exposure to a used comb, a cookie on the floor, and a bedpan filled with toilet water. Results indicated that disgust sensitivity was significantly associated with anxious and avoidant responding to the contamination-related BATs. This association remained largely intact after controlling for gender, contamination fear group membership, anxiety, and depression. Contamination cognitions were also significantly related to BAT responses. However, this relationship was fully mediated by disgust sensitivity. These findings indicate that disgust sensitivity has a specific and robust association with contamination concerns commonly observed in obsessive compulsive disorder. The findings are discussed in the context of a disease-avoidance model.