Behavioral avoidance tests and disgust in contamination fears: distinctions from trait anxiety

Psychometric Properties of the Dutch Child Avoidance Measure

Avoidance is considered a hallmark feature of child anxiety, but convenient measures are scarce. This study examined the psychometric properties of the Child Avoidance Measure (CAM) in a Dutch population, focusing mainly on the child-version. We included children 8 to 13 years old from a community sample (n = 63, longitudinal design) and a sample of high-anxious children (n = 92, cross-sectional design). Regarding the child-version, the internal consistencies were acceptable to good with moderate test-retest reliability. The validity analyses showed encouraging results. High-anxious children had higher avoidance scores than children from a community sample. Regarding the parent-version, both the internal consistency and test-retest validity were excellent. Overall, this study confirmed the sound psychometric properties and usefulness of the CAM. Future studies should focus on the psychometric properties of the Dutch CAM in a clinical sample, assess its ecological validity more extensively, and examine more psychometric features of the parent-version.

Once in Contact, Forever Contaminated! Introducing a Clinically Validated Imagery- and Video-Based Chain of Contagion Task for the Measurement of Disgust and Contamination Change in Experimental Research and Clinical Practice

Tolin et al. (2004) developed the Chain of Contagion Task (CCT) to experimentally test the law of contagion and looming vulnerability (LV). In the CCT, contaminated pencils are brought into contact with clean pencils. The degree of contamination transferred to further new pencils refers to the level of biased contagious beliefs. Although this could be an important transdiagnostic tool, the usability of the original paradigm has been very laborious. Therefore, an imagery- and video-based CCT is introduced and validated in Study 1 in a nonclinical sample with 85 participants. In Study 2, the imagery-based CCT was validated in a clinical study with 15 participants diagnosed with contamination-related obsessive-compulsive disorder (C-OCD), 15 participants suffering from an anxiety disorder, and 15 nonclinical controls. The number of participants is consistent with those in Tolin's original sample and the statistical evaluation of Study 2 was preregistered. Both CCT could be validated and the results could be replicated. In the imagery-based CCT, the C-OCD group displayed significantly higher contamination ratings, avoidance tendencies and LV than the two control groups. We argue that this open access diagnostic instrument can be applied in research as well as in therapeutic practice (Download CCT videos and imagery: https://doi.org/10.5281/zenodo.7730459).

Neuroethics: what the study of brain disorders can tell about moral behavior

The growing interest in the study of morality has led to the birth of a new discipline in the field of moral philosophy called Neuroethics, a multidisciplinary approach that aims to combine philosophy and neuroscience. In this editorial, we explored the relevance of clinical models affected by neurological/psychiatric disorders to learn more about mechanisms sub-serving ethical behaviour at neural and cognitive level.

Behavioral avoidance tasks for eliciting disgust and anxiety in contamination fear: An examination of a test for a combined disgust and fear reaction

While research supports the role of disgust in contamination OCD, there is also an overlap with fear in motivating avoidance. The "heebie-jeebies" is an emotional response associated with fear and disgust that motivates avoidance of contact with skin-transmitted pathogens (e.g., parasites). This motivation aligns with characteristics of contamination OCD. From a screening of undergraduate students (N = 188), contamination fearful (n = 14), high trait-anxious (n = 14), and low trait-anxious (n = 18) groups were created. Participants engaged in disgust, fear, and "heebie-jeebies" behavioral avoidance tasks. Participants rated "heebie-jeebies" emotion, physical sensations, and behavioral urges. Duration or refusal of task was recorded. A significant interaction effect was found for disgust and anxiety. Participants with higher disgust reported higher "heebie-jeebies" emotion at high, but not low, levels of anxiety. Exploratory analyses revealed that many contamination fearful and high trait-anxious participants refused to complete the task. The interaction of disgust and anxiety significantly predicted the probability of refusal. Participants with higher disgust and anxiety were more likely to refuse to complete the task. Results suggest that the "heebie-jeebies" motivates avoidance of skin-transmitted pathogens. Future research is warranted to further investigate the "heebie-jeebies" and how it relates to contamination concerns.

Reappraisal of disgust: Self-report and behavioural assessment of individuals with moderate to high contamination fears

Previous research has linked certain psychological disorders, including obsessive-compulsive disorder (OCD), to the experience of disgust and how it is interpreted/appraised. Therefore, the present study examined whether targeting primary and secondary disgust appraisals (i.e., cognitive reappraisal) in individuals with moderate to high OCD-relevant contamination fears can effectively reduce disgust. Fifty-two participants were randomly assigned to one of three conditions; two of which involved reading a brief script modifying either a primary disgust appraisal (i.e., likelihood of a feared outcome) or a secondary disgust appraisal (i.e., the individual's ability to cope), and a third control condition with no reappraisal script. Following this experimental manipulation of disgust appraisal, participants completed two contamination-relevant behavioural approach tasks which involved 1) increasing proximity to, and eventually touching, a dead cockroach, and 2) drinking apple juice from an unused urine sample collection container. Results indicated that the interventions successfully modified their intended appraisal targets. Furthermore, on the second behavioural approach task, the secondary reappraisal condition demonstrated significantly less disgust-related avoidance relative to the control condition and reported significantly less disgust relative to the primary reappraisal condition. Our results incrementally add to the existing literature that emphasises the potential advantages of modifying disgust appraisals and specifically secondary disgust appraisals when treating disgust-based psychological disorders.

Is disgust in obsessive-compulsive disorder mediated by fear of pathogens?

Individuals with obsessive-compulsive disorder (OCD) tend to report higher levels of disgust, but not much is known about factors that might underlie this relationship. The present study was motivated by the behavioral immune theory, which suggests that disgust has evolved as a protective reaction to potential presence of disease agents in the immediate environment. We examined the relationships between the intensity of experienced physical disgust, perceived vulnerability to disease, and OCD symptoms. The intensity of experienced disgust was assessed with a recent procedure whereby participants rate how disgusted they feel in response to color versus black-and-white pictures that evoke physical disgust. In addition to this procedure, participants (N = 403) completed measures of perceived vulnerability to disease, OCD symptoms, depression and anxiety. OCD symptoms were positively related to the physical disgust evoked by the pictures, and this relationship was mediated by reported emotional discomfort in contexts that connote a potential for pathogen transmission. Replicating previous findings, color pictures were rated as more disgusting than black-and-white pictures overall, and this effect was especially pronounced among people with higher OCD tendencies. These results suggest that, consistent with behavioral immune theory, disgust in OCD is a basic, concrete emotion that is at least partly mediated by fear of pathogens.

The effects of exposure on the generalization of habituation on multiple indices of disgust

Examination of habituation to disgust-related stimuli has received limited experimental investigation. In this study, 38 undergraduates were divided into two groups. The vomit-blood (VB) group was first exposed to a realistic approximation of vomit and allowed to habituate to this stimulus, while the blood-vomit (BV) group was first allowed to habituate to a realistic approximation of blood. Following the habituation phase, each group underwent a short exposure to the unexposed stimuli (blood in the VB group, vomit in the BV group). Physiological and self-report assessments were collected during exposure. Self-report habituation was observed for both groups. In addition, only muscle tension at the levator labii and heart rate in the VB group demonstrated significant changes that could be interpreted as habituation. Consistent with previous literature, muscle tension at the levator labii appeared to be a unique indicator of disgust responding. Implications and suggestions for future research are discussed.

Discriminative Validity of the Dimensional Obsessive-Compulsive Scale for Separating Obsessive-Compulsive Disorder From Anxiety Disorders

Objective: We investigated the diagnostic efficiency and clinical utility of the Dimensional Obsessive-Compulsive Scale (DOCS) and subscales for distinguishing obsessive-compulsive disorder (OCD) from anxiety disorders (ADs). Method: A total of 369 participants (167 male, M_age = 29.61 years) diagnosed with DSM-IV OCD or AD, recruited from specialty clinics across the United States, completed clinical interviews and self-report questionnaires, including the DOCS. Receiver operating characteristic analyses and diagnostic likelihood ratios (DiLRs) determined discriminative validity and provided clinical utility. Logistic regressions tested for incremental validity in the DOCS-total scale and subscales in predicting OCD status. Results: The DOCS-total scale and Contamination subscale performed best in differentiating between OCD and AD diagnosis (DOCS-total: Area under curve [AUC] = .75, p < .001; Contamination: AUC = .70, p < .001) as compared with the other subscales. At high scores (DOCS-total: 28+, Contamination: 6+), Contamination was more effective than the DOCS-total in differentiating OCD from ADs, with high scores in Contamination quadrupling OCD odds and DOCS-total by about threefold (Contamination DiLR+ = 4.04, DOCS-total DiLR+ = 2.82). At low scores (DOCS-total: 0-9, Contamination: 0-2), the converse was true, with low scores in Contamination cutting OCD odds by half and DOCS-total by one fifths (Contamination DiLR- = 0.52, DOCS-total DiLR- = 0.23). Conclusion: At high scores, the Contamination subscale is the most helpful subscale to differentiate OCD and ADs. For low scores, the DOCS-total scale performs the best among the scales.

Predicting Contamination Aversion Using Implicit and Explicit Measures of Disgust and Threat Overestimation

Explicit measures of disgust and threat overestimation have consistently been found to be involved in contamination aversion. However, evidence of the involvement of these factors at the implicit level is mixed, and the role of both responses has not been looked at concurrently. This study aimed to compare the ability of implicit and explicit measures of disgust and threat overestimation to predict contamination aversion and whether this depends on the type of contaminant. Sixty-five participants completed explicit and implicit measures of disgust and threat overestimation, as well as several measures of contamination aversion, including obsessive-compulsive tendencies, and contamination fear and avoidance of contaminants directly associated with disease (direct contaminants) and harmful substances (harm contaminants). It was found that both explicit disgust and explicit threat overestimation predicted contamination-fear obsessive-compulsive tendencies. Explicit disgust predicted contamination fear and avoidance of direct contaminants, whereas explicit threat overestimation predicted contamination fear and avoidance of harm contaminants. The involvement of implicit processes was weak, with some suggestion of difficulty disengaging predicting avoidance of contaminants. Implications for understanding dysfunctional contamination aversion are discussed.

Examination of Responses Involved in Contamination Aversion Based on Threat Type

There is evidence that different types of contaminants produce different responses and have different motivations for avoidance. Contaminants directly associated with disease (direct contaminants) are motivated by disgust avoidance, whereas contaminants indirectly associated with disease (indirect contaminants) and contaminants associated with harmful substances (harm contaminants) are motivated by harm avoidance and threat estimations. This study aims to confirm this distinction between contaminant types and examine the role of cognitive load, awareness and time on processing these threats. One hundred and four participants completed three chain of contagion tasks with direct, indirect, and harm contaminants. Cognitive load, awareness of contamination and time were manipulated during the tasks. Consistent with previous findings, direct contaminants produced stronger disgust responses, while harm and indirect contaminants produced stronger threat estimations. Increasing cognitive load did not impact processing of any type of contaminant. There was evidence that a time delay reduced the spread of contagion for all contaminants. This highlights the importance of time in altering the perception of contamination threat. Implications and future research directions are discussed.

Implications of the Research Domain Criteria project for childhood anxiety and its disorders

Anxiety disorders are among the most prevalent psychiatric disorders in youth; however, progress in treatment for childhood anxiety has stalled over the past decade. The National Institute of Mental Health (NIMH) Research Domain Criteria (RDoC) project represents a shift toward a dimensional and interdisciplinary approach to psychiatric disorders; this shift can reframe developmental psychopathology for childhood anxiety and facilitate novel advances in its classification and treatment. Here we highlight constructs in the Systems for Social Processes and the Negative Valence System domains of RDoC, as they relate to childhood anxiety disorders. Childhood anxiety relates to both RDoC domains. In terms of social processes, through natural reliance on parents to reduce children's fear, attachment represents one particular social process, which plays a central role in anxiety among youth. In terms of negative valence, considerable research links threat conditioning to pediatric anxiety. Finally, fronto-amygdala circuitry relates to all three entities, as it has been shown to underly both attachment processes and threat learning, while it also has been consistently implicated in anxiety disorders across development. Through integrative and translational approaches, RDoC provides unique opportunities and simultaneous challenges for advancing the understanding and treatment of childhood anxiety disorders.

The effects of cognitive reappraisal on conditioned disgust in contamination-based OCD: An analogue study

Experimental research has shown that conditioned disgust is resistant to extinction, which may account for the slower habituation to disgust relative to fear in contamination-based obsessive-compulsive disorder (OCD). However, few studies have examined the efficacy of interventions that may attenuate conditioned disgust responses. Studies of cognitive reappraisal have demonstrated that reinterpreting a stimulus can alter emotional responding. This technique is based on cognitive theories which suggest that anxiety disorders arise from biased cognitions; therefore, changing a person's thoughts will elicit durable changes in emotional responses. Given the demonstrated effectiveness of cognitive reappraisal, the present study examined whether cognitive reappraisal would attenuate conditioned disgust responses. We conditioned participants high in contamination fear (n=55) using images of neutral food items (conditioned stimuli; CS) paired with videos of individuals vomiting (unconditioned stimuli; US) while we obtained subjective disgust reports. After conditioning, half of the participants were randomly assigned to cognitive reappraisal training aimed at decreasing their emotional response to the US and CS, while the other half received no such training. The findings showed that cognitive reappraisal participants demonstrated a reduction in learned disgust across sessions and further benefited from extinction. These findings suggest that cognitive reappraisal may be an effective strategy for attenuating learned disgust.

OCD: obsessive-compulsive … disgust? The role of disgust in obsessive-compulsive disorder

Recent research has identified the important role of disgust in the symptomatology of obsessive-compulsive disorder (OCD). Exaggerated and inappropriate disgust reactions may drive some of the symptoms of OCD, and in some cases, may even eclipse feelings of anxiety. This paper reviews behavioural and neuroimaging research that recognizes the prominent role of disgust in contributing to OCD symptoms, especially contamination-based symptoms. We discuss how elevated behavioural and biological markers of disgust reported in OCD populations support the need for alternative clinical treatment strategies and theoretical models of OCD.

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.

Core, social and moral disgust are bounded: A review on behavioral and neural bases of repugnance in clinical disorders

Disgust is a multifaceted experience that might affect several aspects of life. Here, we reviewed research on neurological and psychiatric disorders that are characterized by abnormal disgust processing to test the hypothesis of a shared neurocognitive architecture in the representation of three disgust domains: i) personal experience of 'core disgust'; ii) social disgust, i.e., sensitivity to others' expressions of disgust; iii) moral disgust, i.e., sensitivity to ethical violations. Our review provides some support to the shared neurocognitive hypothesis and suggests that the insula might be the "hub" structure linking the three domains of disgust sensitivity, while other brain regions may subserve specific facets of the multidimensional experience. Our review also suggests a role of serotonin core and moral disgust, supporting "neo-sentimentalist" theories of morality, which posit a causal role of affect in moral judgment.

Altered olfactory processing and increased insula activity in patients with obsessive-compulsive disorder: An fMRI study

Obsessive-compulsive disorder (OCD) patients show increased insula activation to disgust-inducing images compared to healthy controls (HC). We explored whether this disgust reactivity was also present in the olfactory domain by conducting the first fMRI study of olfaction in OCD. Neural activation in response to pleasant and unpleasant odors (vs. unscented air) was investigated in 15 OCD and 15 HC participants using fMRI. OCD participants (vs. HC) had increased left anterior insula activation to unpleasant odors (vs. unscented air), which positively correlated with their disgust sensitivity and ratings of the unpleasantness and intensity of those odors. OCD participants (vs. HC) showed increased activation of caudate nucleus and left anterior and posterior insula to pleasant odors (vs. unscented air), which positively correlated with their OCD symptom severity, trait anxiety, frequency of feeling disgust, and odor intensity ratings. OCD participants had increased anterior insula activation to both pleasant and unpleasant odors, which correlated with their OCD symptoms, anxiety, disgust sensitivity, and frequency of feeling disgust. OCD patients might have a negative cognitive bias and experience all stimuli, regardless of valence, as being more unpleasant than healthy people. These findings further elucidate the neural underpinnings of OCD and may contribute to more effective treatments.

Effects of Experienced Disgust on Morally-Relevant Judgments

Although disgust has been implicated in moral judgments, the extent to which the influence of disgust on moral judgment is distinct from other negative affective states remains unclear. To address this gap in knowledge, participants in Study 1 were randomized to a disgust (hand submersion in imitation vomit), discomfort (hand submersion in ice water), or neutral (hand submersion in room temperature water) affect condition while moral judgments of offenses were simultaneously assessed. The results showed that participants in the discomfort condition made the most severe moral judgments, particularly for moderate offenses. To examine if disgust may have more of an effect on some moral violations than others, participants in Study 2 were randomized to similar affect inductions while judgments of purity and non-purity offenses were simultaneously assessed. The results showed that those who had their hand submerged in imitation vomit recommended harsher punishment for purity violations relative to moral violations unrelated to purity. The opposite was true for those who submerged their hands in ice water, whereas punishment ratings for purity and non-purity violations did not significantly differ for those who submerged their hands in room temperature water. The implications of these findings for further delineating the specific role of experienced disgust in moral decision-making are discussed.

Neural correlates of emotional response inhibition in obsessive-compulsive disorder: A preliminary study

Failure to inhibit recurrent anxiety-provoking thoughts is a central symptom of obsessive-compulsive disorder (OCD). Neuroimaging studies suggest inhibitory control and disgust processing abnormalities in patients with OCD. However, the emotional modulation of response inhibition deficits in OCD and their neural correlates remain to be elucidated. For this preliminary study we administered an adapted affective response inhibition paradigm, an emotional go/no-go task, during fMRI to characterize the neural systems underlying disgust-related and fear-related inhibition in nine adults with contamination-type OCD compared to ten matched healthy controls. Participants with OCD had significantly greater anterior insula cortex activation when inhibiting responses to both disgusting (bilateral), and fearful (right-sided) images, compared to healthy controls. They also had increased activation in several frontal, temporal, and parietal regions, but there was no evidence of amygdala activation in OCD or healthy participants and no significant between-group differences in performance on the emotion go/no-go task. The anterior insula appears to play a central role in the emotional modulation of response inhibition in contamination-type OCD to both fearful and disgusting images. The insula may serve as a potential treatment target for contamination-type OCD.

Self-Regulation of Anterior Insula with Real-Time fMRI and Its Behavioral Effects in Obsessive-Compulsive Disorder: A Feasibility Study

Introduction

Obsessive-compulsive disorder (OCD) is a common and chronic condition that can have disabling effects throughout the patient's lifespan. Frequent symptoms among OCD patients include fear of contamination and washing compulsions. Several studies have shown a link between contamination fears, disgust over-reactivity, and insula activation in OCD. In concordance with the role of insula in disgust processing, new neural models based on neuroimaging studies suggest that abnormally high activations of insula could be implicated in OCD psychopathology, at least in the subgroup of patients with contamination fears and washing compulsions.

Methods

In the current study, we used a Brain Computer Interface (BCI) based on real-time functional magnetic resonance imaging (rtfMRI) to aid OCD patients to achieve down-regulation of the Blood Oxygenation Level Dependent (BOLD) signal in anterior insula. Our first aim was to investigate whether patients with contamination obsessions and washing compulsions can learn to volitionally decrease (down-regulate) activity in the insula in the presence of disgust/anxiety provoking stimuli. Our second aim was to evaluate the effect of down-regulation on clinical, behavioural and physiological changes pertaining to OCD symptoms. Hence, several pre- and post-training measures were performed, i.e., confronting the patient with a disgust/anxiety inducing real-world object (Ecological Disgust Test), and subjective rating and physiological responses (heart rate, skin conductance level) of disgust towards provoking pictures.

Results

Results of this pilot study, performed in 3 patients (2 females), show that OCD patients can gain self-control of the BOLD activity of insula, albeit to different degrees. In two patients positive changes in behaviour in the EDT were observed following the rtfMRI trainings. Behavioural changes were also confirmed by reductions in the negative valence and in the subjective perception of disgust towards symptom provoking images.

Conclusion

Although preliminary, results of this study confirmed that insula down-regulation is possible in patients suffering from OCD, and that volitional decreases of insula activation could be used for symptom alleviation in this disorder.

Effective behavioural strategies for reducing disgust in contamination-related OCD: A review

Disgust is an understudied but important emotion in various psychological disorders. Over the last decade, increasing evidence suggests that disgust is also present in various subtypes of obsessive-compulsive disorder (OCD), especially in contamination-related OCD (C-OCD). The treatment of choice for C-OCD is exposure with response prevention, originally designed to reduce fear-associated emotions thought to be acquired through Pavlovian conditioning (PC). However, disgust has been proposed to be acquired through evaluative conditioning (EC) and according to the referential model of this form of learning, there are functional differences between PC and EC that need to be considered in the treatment of disgust-related responses. Alternative strategies suggested by EC-based models include counterconditioning (contingent presentation of the CS with a US of opposite valence) and US revaluation (contingent presentation of the US with US of opposite valence). Drawing on the referential model, this paper reviews evidence for the effectiveness of each strategy to identify the most theoretically sound and empirically valid intervention to reduce disgust in C-OCD.

Change in disgust reactions following cognitive-behavioral therapy for childhood anxiety disorders

Disgust, in addition to fear, is a prominent emotional state associated with avoidance of distressing stimuli. While most of the research in disgust has been conducted in relation to Obsessive-Compulsive Disorder (OCD), recent data has also implicated disgust in the etiology of anxiety disorders in general. Studies have shown that decreases in disgust are key to symptom reduction in individuals with OCD. However, there has been little empirical work exploring whether these interventions are efficacious for childhood anxiety disorders that present with prominent disgust components. This study examined how disgust propensity in children with anxiety disorders responds to cognitive-behavioral therapy (CBT) with an emphasis on exposure. Forty-one children, ages 7 to 17, with anxiety disorders were evaluated for disgust propensity and were treated with intensive, weekly, CBT. It was found that disgust levels decreased following treatment across all anxiety disorder diagnoses, where children with primary OCD exhibited significantly greater reductions. Clinical implications and suggestions for further research of the treatment of disgust in relation to childhood anxiety disorders are discussed.

Disgust: the disease-avoidance emotion and its dysfunctions

This review analyses the accumulating evidence from psychological, psychophysiological, neurobiological and cognitive studies suggesting that the disease-avoidance emotion of disgust is a predominant emotion experienced in a number of psychopathologies. Current evidence suggests that disgust is significantly related to small animal phobias (particularly spider phobia), blood-injection-injury phobia and obsessive-compulsive disorder contamination fears, and these are all disorders that have primary disgust elicitors as a significant component of their psychopathology. Disgust propensity and sensitivity are also significantly associated with measures of a number of other psychopathologies, including eating disorders, sexual dysfunctions, hypochondriasis, height phobia, claustrophobia, separation anxiety, agoraphobia and symptoms of schizophrenia--even though many of these psychopathologies do not share the disease-avoidance functionality that characterizes disgust. There is accumulating evidence that disgust does represent an important vulnerability factor for many of these psychopathologies, but when disgust-relevant psychopathologies do meet the criteria required for clinical diagnosis, they are characterized by significant levels of both disgust and fear/anxiety. Finally, it has been argued that disgust may also facilitate anxiety and distress across a broad range of psychopathologies through its involvement in more complex human emotions such as shame and guilt, and through its effect as a negative affect emotion generating threat-interpretation biases.

Disgust propensity in obsessive-compulsive disorder: cross-sectional and prospective relationships

BACKGROUND AND OBJECTIVES

Findings from non-clinical samples suggest that disgust propensity is associated with contamination concerns in obsessive-compulsive disorder (OCD). However, studies of clinical samples have yielded conflicting results. We investigated the relationship between disgust propensity and OCD symptoms in a clinical sample and examined whether changes in disgust propensity are associated with changes in OCD symptoms.

METHODS

One hundred and nine OCD participants completed measures of disgust propensity and OCD symptoms. Sixty of these underwent a six-month follow-up assessment.

RESULTS

At the baseline assessment, disgust propensity was associated with all OCD symptom dimensions except hoarding. Changes in overall disgust propensity between baseline and the six-month follow-up assessment were associated with changes in overall self-reported OCD symptoms but not with changes in contamination-based OCD symptoms or changes in interviewer-assessed OCD symptoms.

LIMITATIONS

There was substantial participant attrition between the baseline and follow-up assessments.

CONCLUSIONS

Our study is the first to investigate prospective relationships between disgust propensity and OCD across a six-month interval. Our findings suggest that if there is an association between changes in disgust propensity and changes in contamination-based OCD symptoms its magnitude is likely to be small.

Disgust recognition in obsessive-compulsive disorder: diagnostic comparisons and posttreatment effects

OBJECTIVE

To examine whether disgust recognition deficits are present and specific to obsessive-compulsive disorder (OCD), and the extent to which this deficit, if present, can be reduced in cognitive-behavioural therapy (CBT).

METHOD

Responses to the Pictures of Facial Affect (POFA) were examined in patients with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, diagnosed OCD (n = 20), panic disorder with agoraphobia (PDA; n = 15), and generalized social phobia (GSP; n = 15) and a second, independent OCD sample of treatment responders to CBT (n = 11).

RESULTS

There were significant and statistically large disgust recognition differences between the OCD group and comparison PDA and GSP groups. However, patients with OCD treated with CBT showed disgust recognition scores that were equivalent to the PDA and GSP groups, significantly better than the untreated OCD sample, and equivalent to scores from the original POFA nonaffected standardization sample.

CONCLUSIONS

These results provide support for the presence of disgust recognition impairment in OCD, and provide preliminary evidence that disgust recognition impairments may improve with treatment.

Disgust proneness and obsessive-compulsive symptoms in a clinical sample: structural differentiation from negative affect

Although a growing body of research has revealed robust associations between disgust and obsessive-compulsive disorder (OCD) symptoms, there remains a paucity of research examining the specificity of this association in clinical samples. The present study employed structural equation modeling to differentiate disgust from negative affect in the prediction of OCD symptoms in a clinical sample (n=153). Results indicate that disgust and negative affect latent factors were independently related to OCD symptoms. However, when both variables were simultaneously modeled as predictors, latent disgust remained significantly associated with OCD symptoms, whereas the association between latent negative affect and OCD symptoms became nonsignificant. Multiple statistical tests of mediation converged in support of disgust as a significant intervening variable between negative affect and OCD symptoms. The implications of these findings for further delineating the role of individual differences in disgust proneness in the development of OCD are discussed.

Functions of compulsions in obsessive-compulsive disorder

OBJECTIVES

The key function of compulsions in obsessive-compulsive disorder (OCD) is to alleviate anxiety or distress caused by the obsessions, but compulsions may also have other functions. The main aim of this study was to systematically ascertain what motivates individuals with OCD to perform compulsions.

METHOD

A total of 108 adults with OCD were assessed with the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) and the Functions of Compulsions Interview. The latter instrument elicits the functions of identified compulsions.

RESULTS

The functions of 218 compulsions were identified. The mean number of functions per compulsion in the whole sample was 2.94 and the vast majority of compulsions (85.3%) were performed for more than one reason. The total number of functions of compulsions endorsed for the three main compulsions correlated with Y-BOCS total scores (r = 0.37, p < 0.001). Compulsions were most frequently performed automatically and to decrease distress or anxiety, but there was substantial variation, depending on the type of compulsion. Hoarding was often performed for reasons not related to any other compulsion (involving a perceived need for collected objects), whereas ordering/symmetry/repeating compulsions were frequently performed to achieve a 'just right' feeling. Checking was frequently performed because of the belief that something bad or unpleasant would happen if one failed to check; washing/cleaning compulsions were most frequently performed to decrease distress or anxiety and automatically, and mental compulsions were performed automatically far more often than for other reasons.

CONCLUSIONS

The majority of compulsions have more than one function and they are often performed automatically. The finding of different functions of compulsions in different types of compulsions provides some support to the subtyping of OCD on the basis of obsessions and compulsions. Identifying functions of compulsions allows better understanding of the functional relationship between obsessions and compulsions, which may have implications for cognitive-behavioural therapy of OCD.

Unique affective and cognitive processes in contamination appraisals: Implications for contamination fear

A large body of evidence suggests an important role of disgust in contamination fear (CF). A separate line of research implicates various cognitive mechanisms in contamination fear, including obsessive beliefs, memory biases, and delayed attentional disengagement from threat. This study is an initial attempt to integrate these two lines of research and examines whether disgust and delayed attention disengagement from threat explain unique or overlapping processes within CF. Non-clinical undergraduate students (N = 108) completed a spatial cueing task, which provided measures of delayed disengagement from frightening and disgusting cues, and a self-report measure of disgust propensity (DP). Participants also completed a chain of contagion task, in which they provided contamination appraisals of an object as a function of degrees of removal from an initial contaminant. Results demonstrated that DP predicted greater initial contamination appraisals, but a sharper decline in estimations across further degrees of removal from the contaminant. Delayed disengagement from disgust cues uniquely predicted sustained elevations in contamination estimations across further degrees of removal from the contaminant. These results suggest that DP and delayed disengagement from disgust cues explain unique and complimentary processes in contamination appraisals, which suggests the utility of incorporating the disparate affective and cognitive lines of research on CF.

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.

Incremental specificity of disgust sensitivity in the prediction of obsessive-compulsive disorder symptoms: Cross-sectional and prospective approaches

The present study examines the association between disgust sensitivity (DS) and obsessive-compulsive disorder (OCD) symptoms in two non-clinical samples. Findings from Study 1 (n=270) revealed a significant association between DS and OCD symptoms even after controlling for negative affect and anxiety sensitivity. Subsequent analysis also revealed a specific association between DS and the washing subtype of OCD symptoms when controlling for other OCD symptom dimensions. DS did not significantly predict residual change in total symptoms of OCD over a 12-week period (n=300) when controlling for risk factors for anxiety disorder symptoms in general (e.g., negative affect, anxiety sensitivity) and OCD specifically (e.g., obsessive beliefs) in Study 2. However, exploratory analyses suggest that DS may be predictive of residual change in some OCD symptom subtypes but not others. Implications of these findings for future research on the role of disgust in OCD are discussed.

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.

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.

Measuring State Disgust

The aim of the present analysis was to develop and evaluate a state disgust questionnaire (Ekel-State-Fragebogen, ESF) in German, considering three student sample studies. Twenty-six items were constructed using information drawn from literature research and from the self-report of subjects after an induction of disgust. In Study 1, the questionnaire was given to 160 subjects after disgust induced by a film sequence and in a second session without induction. Study 2 had an experimental design where disgust or positive mood was induced by scents (60 subjects), followed by a state disgust measurement. Study 3, a repeated measure design, involved 102 subjects in whom disgust, fear, and neutral mood were induced by film sequences. Data from all three studies supported a one-factor solution. The ESF showed the highest means in disgust conditions. The correlations of the ESF with state anxiety (STAI State) ranged from .68 to .79, with trait disgust from .42 to .48 in disgust conditions, and with trait anxiety from .24 to .41. Thus, the ESF showed good results in measuring state disgust in a specific, reliable, and valid manner. Based on these results, a short version of 15 items was developed.

Trait anxiety, disgust sensitivity, and the hierarchic structure of fears

This paper describes an evaluation of Taylor's (1998) hierarchic model of fears and its relationship to trait anxiety and disgust sensitivity (DS). In Study 1 (N=420), a confirmatory factor analysis supported a hierarchic structure of fears. Next, an analysis using structural equation modeling indicated that trait anxiety is associated with claustrophobic and social fears, whereas DS is associated with all four fear subtypes examined (claustrophobic, social, blood-injection-injury and animal). However, trait anxiety and DS did not account for all variance shared by fear subtypes. The addition of a generalized "fear factor" accounted for significant residual shared variance between the four fear subtypes, beyond that accounted for by trait anxiety and DS. Study 2 (N=213) generally replicated these results. Findings suggest that the hierarchic structural model of fears would benefit from inclusion of trait anxiety and DS as higher-order contributors to fearfulness.

Symptom subtypes of obsessive-compulsive disorder: are they relevant for treatment?

Several symptom subtypes of obsessive-compulsive disorder (OCD) have been identified on the basis of the predominant obsessions and compulsions. The objectives of the present article were to review the literature on the relationship between OCD symptom subtypes and treatment response and to suggest strategies that might assist with the choice of treatment and improve treatment outcome in patients with various subtypes. An extensive literature search was performed, relevant studies were identified, and their results reported. Overt compulsions were generally associated with a relatively good response to the behaviour therapy technique of exposure and response prevention (ERP) and with poorer response to serotonin re-uptake inhibitors (SRIs). Washing/cleaning and checking compulsions tend to respond well to ERP, whereas the majority of studies show that washing/cleaning compulsions are associated with a poorer response to SRIs. Most studies suggest that patients with the symmetry, ordering and arranging subtype do not fare worse with ERP and SRIs than patients with other symptom subtypes. Some studies suggested that obsessions might respond to SRIs somewhat better than to ERP. In the majority of the studies, hoarding and the subtype characterized by sexual or religious obsessions and absence of overt compulsions ('pure obsessions') have been associated with poor response to ERP and SRIs. It was concluded that treatment strategies cannot be precisely tailored to OCD symptom subtypes. Many other factors influence the outcome of treatment and need to be considered along with the symptom subtypes when making decisions about treatment. While ERP and SRIs remain the mainstay of treatment regardless of the symptom subtype, the addition of cognitive therapy techniques and/or antipsychotic medications may enhance treatment response in the presence of certain features discussed in the article.

Disgust sensitivity as a predictor of obsessive-compulsive contamination symptoms and associated cognitions

Disgust sensitivity has been hypothesized to play a key role in the etiology and maintenance of several anxiety disorders. The association between disgust sensitivity, trait anxiety, and washing and contamination-related concerns was tested using two different measures of obsessive-compulsive contamination fears using linear structural modeling. Two different models were tested, one where trait anxiety mediated the relationship between disgust sensitivity and contamination fear, and a second model unmediated by trait anxiety. A total of 740 undergraduates completed self-report measures of disgust sensitivity, trait anxiety, and obsessive-compulsive symptoms for course credit. The results indicated that there was insufficient evidence for the mediating role of trait anxiety, and the more parsimonious structural models specifying direct effects between disgust sensitivity and both washing and contamination concerns fit the data well. The results of this research support the central role of disgust in contamination fear.

Vulnerability to mental contamination

Mental contamination refers to feelings of contamination that arise without physical contact with a contaminant. Mental contamination has been documented among sexual assault victims, some of whom report feeling dirty and wanting to wash in response to memories of the assault. This study examined variables associated with increased vulnerability to mental contamination. Female undergraduates (n=100) filled out a series of questionnaires and listened to an audiotape that instructed them to imagine experiencing a forced kiss by an undesirable male. Controls (n=20) imagined a consensual kiss by a desirable male. Women in the non-consensual condition reported stronger feelings of dirtiness and urge to wash than those in the consensual condition. Twenty-seven women in the non-consensual condition spontaneously rinsed in order to alleviate physical sensations evoked by the tape. Regression analyses revealed that significant predictors of dirtiness included contact contamination fear and disgust sensitivity, and there was a trend for anxiety sensitivity to predict dirtiness. Contact contamination fear was also a significant predictor of urge to wash. Prior experience with unwanted sexual contact was a significant predictor of rinsing, and there was a trend for fear of negative evaluation to predict rinsing. Discussion focuses on the implications of these findings for our understanding of mental contamination.