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

The present study utilizes multiple methods to examine the relationship between disgust and contamination-related obsessive-compulsive disorder (OCD) symptoms in an analogue sample. Questionnaire findings revealed that participants with high OCD contamination concerns showed stronger disgust sensitivity than did participants with low OCD contamination symptoms after controlling for negative affect. High OCD participants (N=30) also reported significantly more disgust than did low OCD participants (N=30) when exposed to a disgust-inducing video, whereas no significant between-group differences were detected on other negative emotional dimensions. Results from a series of disgust-specific behavioral avoidance tasks (BATs) revealed that high OCD participants demonstrated both less compliance and less approach behavior. Subsequent analysis also revealed that disgust sensitivity generally mediated avoidance on the BATs among high OCD subjects. High OCD participants also rated the BATs as more fearful and disgusting than did low OCD participants, with disgust generally emerging as the dominant emotional response. The results are consistent with a disgust-based, disease-avoidance approach in understanding contamination-related OCD themes.     

Different Disgust Domains Specifically Relate to Mental and Contact Contamination Fear in Obsessive-Compulsive Disorder: Evidence From a Path Analytic Model in an Italian Clinical Sample

Both contact contamination (CC) and mental contamination (MC) fears—which combined represent the most common manifestation of obsessive-compulsive disorder (OCD)—have been widely associated with disgust propensity. However, extant research explored this relationship using measures assessing only pathogen-related disgust, not taking into account the potential role played by sexual and moral disgust, despite literature about MC suggesting that this might be particularly relevant. In Study 1, the psychometric properties of the Italian version of the Three Domains of Disgust Scale (TDDS) were assessed in a large Italian community sample. Exploratory and confirmatory factor analyses confirmed the three-factor structure of the TDDS. The scale also showed good internal consistency and construct validity. In Study 2, the differential patterns of relationships between CC and MC and the three disgust domains were explored in an Italian clinical OCD sample using a path analytic approach. The TDDS-Pathogen subscale was a unique predictor of CC while the TDDS-Sexual subscale was a unique predictor of MC, after controlling for anxiety and depression. Surprisingly, the TDDS-Moral subscale was not a predictor of either domain of contamination fear. Limitations and clinical implications are discussed.     

Disgust domains in the prediction of contamination fear

Previous research has shown a relationship between the emotion of disgust and the fear of contamination. Heightened sensitivity to disgust and increased concerns over contamination has been observed in various disorders, such as obsessive-compulsive disorder (OCD) and specific phobias. However, there is a paucity of research identifying the specific domains of disgust that contribute to contamination fear. The present study soughts to determine which domains of disgust elicitors reliably predict scores on a measure of OCD contamination obsessions and washing compulsions. We further conducted exploratory analyses that examined differences in disgust sensitivity among individuals classified as high and low in contamination fear. Three hundred and twenty-three undergraduate participants completed two measures of disgust sensitivity (Disgust Scale; Disgust Emotion Scale) and a measure of contamination fear (Padua inventory, contamination obsessions and washing compulsions subscale). Stepwise multiple regression analyses indicated that contamination fear was best predicted by seven different disgust domains, thereby suggesting that contamination fear is accounted for by generalized, rather than domain-specific, disgust elicitors. The categories of disgust that predicted contamination fear appeared to have an underlying commonality of threat of contagion. The relationship between fear of contamination and disgust sensitivity was more pronounced for animal reminder disgust elicitors as opposed to core disgust elicitors. Results also showed that individuals classified as high in contamination fear scored significantly higher than the low contamination fear group on all disgust domains. Clinical and research implications regarding the interrelationships between fear, disgust, and the fear of contamination are discussed.     

Mental Contamination in Obsessive-Compulsive Disorder: Associations With Contamination Symptoms and Treatment Response

The most common symptom of obsessive-compulsive disorder (OCD) is contamination fear. Feelings of contamination can be provoked through contact with a physical contaminant, referred to as contact contamination (CC), as well as in the absence of one, referred to as mental contamination (MC). Prior research indicates that CC and MC are distinct, and MC may interfere with treatment for CC. However, no study to date has examined how MC may be associated with responses to physical contaminants and treatment response for CC. This study examined the relationships between CC and MC in a sample of individuals with elevated contamination symptoms (N = 88), half of whom met diagnostic criteria for OCD. Participants engaged in three sessions of exposure and response prevention (ERP) for CC and completed self-report measures and behavioral tasks assessing CC and MC at pretreatment, posttreatment, and follow-up. As hypothesized, at pretreatment, MC was positively associated with reactivity to physical contaminants, even after participants washed their hands. ERP for CC was associated with unique changes in CC and MC across self-report and behavioral measures, and greater pretreatment MC predicted greater posttreatment CC, though this effect was evident in only one of two CC measures. Additionally, specificity analyses indicated changes in MC were independent of changes in disgust propensity, a related construct. Pretreatment disgust propensity also predicted treatment outcome, though the addition of pretreatment disgust propensity as a covariate reduced the relationship between pretreatment MC and posttreatment CC to nonsignificance. Results suggest MC plays an important role in the manifestation and treatment of CC symptoms and may represent a manifestation of disgust proneness. Theoretical and clinical implications are discussed.     

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.     

Selective effects of excessive engagement in health-related behaviours on disgust propensity

The present study examined the extent to which engagement in health-related behaviours modulate disgust propensity, a purportedly stable personality trait. Participants were randomised into a health behaviour (n = 30) or control condition (n = 30). After a baseline period, participants in the health behaviour condition spent one week actively engaging in a clinically representative array of health-related behaviours on a daily basis, followed by a second week-long baseline period. Participants in the control condition monitored their normal use of health behaviours. Compared to control participants, those in the health behaviour condition reported significantly greater increases in disgust propensity after the health behaviour manipulation. This effect was most robust for contamination disgust propensity and remained significant when controlling for changes in health anxiety and disease fear. In contrast, self-disgust and anxiety sensitivity did not significantly differ between the two groups as a function of the health behaviour manipulation. Mediational analyses were consistent with the hypothesis that changes in the frequency of health-related behaviours, but not changes in health anxiety and disease fear, mediated the effects of the experimental manipulation on changes in contamination disgust propensity. These findings suggest that the purportedly stable personality trait of disgust propensity can be modulated by excessive engagement in health-related behaviours.     

The moderating effects of contamination sensitivity on state affect and information processing: Examination of disgust specificity

Although contamination sensitivity has been implicated in several disorders, there is a paucity of research examining the influence of this trait on various outcomes. Accordingly, the present study examined the extent to which individual differences in contamination sensitivity moderated state affect in response to a mood induction and subsequent information processing biases, as assessed by a lexical decision task (LDT). It was hypothesised that the moderating effects of contamination sensitivity would be specific to disgust responding to a negative but not positive mood induction, and to reaction times to disgust and fear compared to happy words on the LDT. The findings were largely consistent with this hypothesis, as contamination sensitivity predicted increased disgust and arousal to the negative mood induction. Contamination sensitivity was also a better predictor of reaction times to disgust and fear words than happy words. However, the moderating effect of contamination sensitivity on reaction times on the LDT was not mediated by its effects on response to the negative mood induction. Implications of these findings for conceptualising the role of contamination sensitivity and its association with disgust in specific disorders are discussed.     

Development and Initial Validation of an Abbreviated Spider Phobia Questionnaire Using Item Response Theory

An abbreviated Spider Phobia Questionnaire (SPQ) was developed using methods based in item response theory. Fifteen of the 31 SPQ items that demonstrated good to excellent discrimination along the spider fear continuum were retained in Study 1 that consisted of 1,555 nonclinical and clinical participants. The SPQ-15 demonstrated good internal consistency and correlated highly with the full SPQ. Structural equation modeling revealed that the SPQ-15 demonstrated excellent convergent validity, with strong associations with small animal disgust and other phobic symptoms. Supportive evidence was also found for divergent validity in relation to panic-related symptoms. The SPQ-15 was uniquely predictive of avoidance behavior and fear and disgust responding towards spiders in nonclinical, analogue, and treatment-seeking samples in Studies 2, 3, and 4. Lastly, in Study 5, the SPQ-15 was sensitive to the effects of exposure-based treatment. These findings suggest that the SPQ-15 has considerable strengths, including decreased assessment and scoring time while retaining high reliability, validity, and sensitivity.     

The moderating effects of contamination sensitivity on state affect and information processing: examination of disgust specificity

Although contamination sensitivity has been implicated in several disorders, there is a paucity of research examining the influence of this trait on various outcomes. Accordingly, the present study examined the extent to which individual differences in contamination sensitivity moderated state affect in response to a mood induction and subsequent information processing biases, as assessed by a lexical decision task (LDT). It was hypothesised that the moderating effects of contamination sensitivity would be specific to disgust responding to a negative but not positive mood induction, and to reaction times to disgust and fear compared to happy words on the LDT. The findings were largely consistent with this hypothesis, as contamination sensitivity predicted increased disgust and arousal to the negative mood induction. Contamination sensitivity was also a better predictor of reaction times to disgust and fear words than happy words. However, the moderating effect of contamination sensitivity on reaction times on the LDT was not mediated by its effects on response to the negative mood induction. Implications of these findings for conceptualising the role of contamination sensitivity and its association with disgust in specific disorders are discussed.     

Incompleteness and Disgust Predict Treatment Outcome in Pediatric Obsessive-Compulsive Disorder

Increasing evidence suggests that pediatric obsessive-compulsive disorder (OCD) is motivated not only by fear but also by feelings of incompleteness and disgust. However, it is currently unclear whether emotion involvement in OCD symptoms is associated with treatment response in youth with OCD. The present study examined whether treatment outcome for youth with OCD was predicted by the degree to which fear, disgust, and incompleteness were involved in baseline OCD symptoms. Children and adolescents with OCD entering treatment for this condition (N = 111) were administered standardized OCD symptom measures and an interview designed to assess the degree of fear, incompleteness, and disgust experienced during current OCD symptoms. Follow-up assessments occurred on average 13 months after baseline with each participant coded for outcome according to internationally acknowledged change criteria for pediatric OCD. Higher levels of incompleteness and disgust as part of baseline OCD symptoms predicted poorer outcome. The degree of fear during baseline OCD symptoms did not predict outcome. If replicated under controlled conditions, these results suggest that incompleteness and disgust may act as barriers to improvement in pediatric OCD and that treatment modifications that target these emotion-related motivators may improve outcome for a subset of youth.     

Core,animal reminder,and contamination disgust: Three kinds of disgust with distinct personality,behavioral, physiological,and clinical correlates

We examined the relationships between sensitivity to three kinds of disgust (core, animal-reminder, and contamination) and personality traits, behavioral avoidance, physiological responding, and anxiety disorder symptoms. Study 1 revealed that these disgusts are particularly associated with neuroticism and behavioral inhibition. Moreover, the three disgusts showed a theoretically consistent pattern of relations on four disgust-relevant behavioral avoidance tasks in Study 2. Similar results were found in Study 3 such that core disgust was significantly related to increased physiological responding during exposure to vomit, while animal-reminder disgust was specifically related to physiological responding during exposure to blood. Lastly, Study 4 revealed that each of the three disgusts showed a different pattern of relations with fear of contamination, fear of animals, and fear of blood–injury relevant stimuli. These findings provide support for the convergent and divergent validity of core, animal-reminder, and contamination disgust. These findings also highlight the possibility that the three kinds of disgust may manifest as a function of different psychological mechanisms (i.e., oral incorporation, mortality defense, disease avoidance) that may give rise to different clinical conditions. However, empirical examination of the mechanisms that underlie the three disgusts will require further refinement of the psychometric properties of the disgust scale.     

Disgust,scrupulosity and conservative attitudes about sex: Evidence for a mediational model of homophobia

In the present study, core disgust predicted negative attitudes toward homosexuals even after controlling for contamination fear. The effect of core disgust on negative attitudes toward homosexuals was indirect, partially mediated by conservative sexual attitudes and religiosity. The effects of religious principles on negative attitudes toward homosexuals were indirect, via conservative sexual beliefs. These results establish a link between disgust and negative attitudes towards homosexuals that is not fully accounted for by contamination concerns, but rather is partially accounted for by conservative sexual ideology and religiosity.     

Thought-action fusion and its relationship to schizotypy and OCD symptoms

Thought-action fusion (TAF) is a cognitive bias that has been linked to obsessive-compulsive disorder (OCD). Preliminary evidence suggests schizotypal traits may be associated with some types of OCD obsessions but not others. We examined the relationship between each of the two major types of TAF (i.e., likelihood and moral), schizotypal traits, and OCD symptoms in 969 nonclinical undergraduate students. We hypothesized that likelihood TAF would be associated with schizotypal traits; whereas moral TAF would not. Consistent with prediction, schizotypal-magical thinking was significantly associated with likelihood TAF even after controlling for the effects of OCD symptoms, general anxiety, and depression. Moreover, the relationship between likelihood TAF and OCD symptoms was significantly attenuated after controlling for schizotypal traits. In contrast, moral TAF demonstrated negligible association with OCD symptoms, depression, or schizotypal traits. These findings provide preliminary support for the linkage between likelihood TAF and schizotypal traits.     

Fear and disgust processing during repeated exposure to threat-relevant stimuli in spider phobia

Although disgust plays a significant role in the etiology of spider phobia, there remains a paucity of research examining the role of disgust in the treatment of spider phobia. Spider fearful participants (N = 46) were randomly assigned to a disgust (view vomit images) or neutral activation (view inanimate objects) condition. They were then repeatedly exposed to a videotaped tarantula, during which time their fear, disgust, and physiological levels were assessed repeatedly. Growth curve analyses indicated that repeated exposure led to significant declines in fear and disgust with no statistically significant differences between the two conditions. However, there was marginal evidence for decreased physiological arousal during repeated exposure among spider fearful participants in the disgust activation condition compared to those in the neutral condition. Reduction in disgust during exposure in the disgust activation condition remained significant after controlling for change in fear, whereas change in fear was no longer significant after controlling for change in disgust. However, the opposite pattern of relations between change in fear and disgust was observed in the neutral activation condition. Higher fear and disgust activation during exposure was also associated with higher fear and disgust responding on a subsequent behavioral task and higher spider fear and disgust at 3-month follow-up. Baseline trait disgust propensity also predicted fear and disgust parameters during repeated exposure. The implications of these findings for the role of disgust in the treatment of spider phobia are discussed.     

An examination of the decline in fear and disgust during exposure-based treatment

It has been suggested that disgust plays a prominent role in the fear of spiders. Participants (N=27) displaying marked spider fear were provided 30 min of self-directed in vivo exposure to an actual tarantula, during which time their fear and disgust levels were assessed repeatedly. Growth curve analyses were then conducted to examine the decay slopes in both fear and disgust and their relationship. Consistent with prediction, exposure led to significant declines in both spider fear and spider-specific disgust but not in global disgust sensitivity. However, the decay slope observed for fear was significantly greater than that for disgust. Further analyses revealed that the reduction in disgust during treatment remained significant even after controlling for change in fear; and similarly, change in fear remained significant even after controlling for change in disgust. Contrary to prediction, disgust levels at pretreatment did not moderate the level of fear activation or fear reduction during treatment. Theoretical and clinical implications of the findings are discussed.     

Specificity of Disgust Domains in the Prediction of Contamination Anxiety and Avoidance: A Multimodal Examination

Although core, animal-reminder, and contamination disgust are viewed as distinct “types” of disgust vulnerabilities, the extent to which individual differences in the three disgust domains uniquely predict contamination-related anxiety and avoidance remains unclear. Three studies were conducted to fill this important gap in the literature. Study 1 was conducted to first determine if the three types of disgust could be replicated in a larger and more heterogeneous sample. Confirmatory factor analysis revealed that a bifactor model consisting of a “general disgust” dimension and the three distinct disgust dimensions yielded a better fit than a one-factor model. Structural equation modeling in Study 2 showed that while latent core, animal-reminder, and contamination disgust factors each uniquely predicted a latent “contamination anxiety” factor above and beyond general disgust, only animal-reminder uniquely predicted a latent “non-contamination anxiety” factor above and beyond general disgust. However, Study 3 found that only contamination disgust uniquely predicted behavioral avoidance in a public restroom where contamination concerns are salient. These findings suggest that although the three disgust domains are associated with contamination anxiety and avoidance, individual differences in contamination disgust sensitivity appear to be most uniquely predictive of contamination-related distress. The implications of these findings for the development and maintenance of anxiety-related disorders marked by excessive contamination concerns 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.     

Specific and differential prediction of health anxiety by disgust sensitivity and propensity

Current models of health anxiety suggest that fear resulting from false alarms to perceived threats to one's health results in the development of hypochondriasis and related disorders. Disgust has been proposed as an affective response that may function as an etiological and maintenance mechanism in health anxiety. Moreover, the way in which an individual perceives the disgust response (disgust sensitivity) may affect health anxiety, separately from their likelihood of experiencing disgust (disgust propensity). The present study utilized multiple hierarchical regression analysis to investigate the degree to which self-reported disgust sensitivity and disgust propensity differentially predict elevated health anxiety in a sample of 620 non-treatment-seeking undergraduates. Further, this effect is tested in comparison to that of anxiety sensitivity, a construct demonstrated to be strongly related to health anxiety. Analyses indicate that disgust sensitivity, rather than disgust propensity, is primarily responsible for this relation. An additional analysis tested the specificity of disgust sensitivity relative to anxiety sensitivity. Disgust sensitivity was no longer significant after including anxiety sensitivity in the model. Suggestions for further evaluation of this relation are provided. These results suggest that although disgust sensitivity may appear related to health anxiety, this relation may be confounded by anxiety sensitivity.     

A comparison of repeated exposure to fearful and disgusting stimuli among spider phobics

This study examined the role of fear and disgust in repeated exposure among spider phobics. Thirty spider phobics were randomly assigned to one of two experimental groups. Both groups completed measures of fear and disgust and performed two initial standardized Behavioral Avoidance Tests (BATs; one with a fear stimulus – live tarantula, and one with a disgust stimulus – dead rat). One group was then repeatedly exposed to the tarantula and the other to the dead rat. Results of the study indicated that exposure to either the disgust stimulus or the live tarantula was associated with significant decreases in fear, avoidance, and disgust. However, it was found that repeated exposure to the fear stimulus produced a greater decrease in avoidance behavior. Results suggest that both types of exposure can be effective in alleviating associated symptoms and provide additional evidence that disgust sensitivity plays a role in the treatment of spider phobia. Copyright © 2010 John Wiley & Sons, Ltd.     

A test of a disease-avoidance model of animal phobias

This study examined the relationship between disgust/contamination sensitivity and fear of animals. The results suggested that sensitivity to disgust and contamination was directly related to scores on the animal phobia and fear of illness and death sub-scales of the Fear Survey Schedule (FSS). Further analysis suggested that disgust/contamination sensitivity was related only to fear of certain groups of animals: namely those animals that are not considered to attack and harm human beings but are considered fear-evoking (e.g. rat, spider, cockroach), and those animals that are normally considered to evoke revulsion (e.g. maggot, snail, slug). Disgust/contamination sensitivity was not related to fear of animals that are considered highly likely to attack and harm human beings (e.g. tiger, lion, shark). These results are discussed as support for a disease-avoidance model of common animal fears.