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

Conceptual-level disgust conditioning in contamination-based obsessive-compulsive disorder

Pavlovian fear conditioning and extinction represent learning mechanisms underlying exposure-based interventions. While increasing evidence indicates a pivotal role of disgust in the development of contamination-based obsessive-compulsive disorder (C-OCD), dysregulations in conditioned disgust acquisition and maintenance, in particular driven by higher-order conceptual processes, have not been examined. Here, we address this gap by exposing individuals with high (HCC, n = 41) or low (LCC, n = 41) contamination concern to a conceptual-level disgust conditioning and extinction paradigm. Conditioned stimuli (CS+) were images from one conceptual category partially reinforced by unconditioned disgust-eliciting stimuli (US), while images from another category served as non-reinforced conditioned stimuli (CS-). Skin conductance responses (SCRs), US expectancy and CS valence ratings served as primary outcomes to quantify conditioned disgust responses. Relative to LCC, HCC individuals exhibited increased US expectancy and CS+ disgust experience, but comparable SCR levels following disgust acquisition. Despite a decrease in conditioned responses from the acquisition phase to the extinction phase, both groups did not fully extinguish the learned disgust. Importantly, the extinction resilience of acquired disgust was more pronounced in HCC individuals. Together, our findings suggest that individuals with high self-reported contamination concern exhibit increased disgust acquisition and resistance to extinction. The findings provide preliminary evidence on how dysregulated disgust learning mechanism across semantically related concepts may contribute to C-OCD.

Is disgust more resistant to extinction than fear? A meta-analytic review of laboratory paradigms

Disgust can be acquired via evaluative conditioning; a process by which a neutral stimulus (conditioned stimulus; CS) comes to be evaluated as disgusting due to its pairing with an inherently disgusting stimulus (unconditioned stimulus; US). Research has shown that conditioned disgust responses are resistant to extinction which may have implications for disorders (i.e., contamination-based obsessive-compulsive disorder, specific phobias, and post-traumatic stress disorder) in which heightened disgust has been implicated. Importantly, extinction is the primary mechanism by which exposure therapies are thought to achieve symptom reduction for these disorders. Exposure therapies were originally modeled on fear extinction, whereas disgust extinction was largely overlooked until recently. Accordingly, differences in the degree to which learned disgust and fear can be attenuated via extinction learning remains unclear. The present investigation was a meta-analysis directly comparing the degree of extinction of conditioned disgust (n = 14) and conditioned fear (n = 14) in laboratory paradigms. Extinction was operationalized as the standardized mean difference (SMD) in evaluative ratings between the CS+ (the CS paired with the US) and CS- (the unpaired CS) after extinction training. Results of a subgroup analysis indicated that disgust (SMD = 0.52) was significantly more resistant to extinction than fear (SMD = 0.37). Additionally, a series of meta-regression analyses indicated that extinction was not influenced by important study characteristics (e.g., sex, age, number of conditioning and extinction trials). The findings suggest that extinction-based approaches may be less effective at attenuating learned disgust and research is needed to better optimize treatments for disgust-related disorders.

Conscious knowledge of CS-UCS contingency information affects extinction retrieval of conditioned disgust responses: Findings from an online de novo disgust conditioning task

Objective

The present study aimed to establish and develop an online de novo conditioning paradigm for the measurement of conditioned disgust responses. We further explored the effects of explicit instructions about the CS-UCS contingency on extinction learning and retrieval of conditioned disgust responses.

Method

The study included a sample of 115 healthy participants. Geometric figures served as conditioned stimuli (CS) and disgust-evoking pictures as unconditioned stimuli (UCS). During disgust conditioning, the CS+ was paired with the UCS (66% reinforcement) and the CS- remained unpaired; during extinction and retrieval, no UCS was presented. Half of the participants (n = 54) received instructions prior to the disgust extinction stating that the UCS will not be presented anymore. 1-2 days or 7-8 days later participants performed a retrieval test. CS-UCS contingency, disgust and valence ratings were used as dependent measures.

Results

Successful acquisition of conditioned disgust response was observed on the level of CS-UCS contingency, disgust and valence ratings. While some decline in valence and disgust ratings during the extinction stage was observed, contingency instructions did not significantly affect extinction performance. Retrieval one week later revealed that contingency instructions increased the discrimination of the CSs.

Conclusions

Extinction of conditioned disgust responses is not affected by explicit knowledge of the CS-UCS contingencies. However, contingency instructions prior to extinction seem to have a detrimental effect on long-term extinction retrieval.

Disgust as a transdiagnostic index of mental illness: A narrative review of clinical populations

Disgust is a basic emotion of rejection, providing an ancestral defensive mechanism against illness. Based on research that documents altered experiences of disgust across several psychopathological conditions, we conducted a narrative review to address the hypothesis that altered disgust may serve as a transdiagnostic index of mental illness. Our synthesis of the literature from past decades suggests that, compared to healthy populations, patients with mental disorders exhibit abnormal processing of disgust in at least one of the analyzed dimensions. We also outline evidence of alterations in brain areas relevant to disgust processing, such as the insula and the interconnected limbic network. Overall, we provide preliminary support for the hypothesis that altered disgust processing may serve as a transdiagnostic index of mental illness.

Pavlovian Disgust Conditioning and Generalization: Specificity and Associations With Individual Differences

Although studies have identified differences between fear and disgust conditioning, much less is known about the generalization of conditioned disgust. This is an important gap in the literature given that overgeneralization of conditioned disgust to neutral stimuli may have clinical implications. To address this knowledge gap, female participants (n = 80) completed a Pavlovian conditioning procedure in which one neutral food item (conditioned stimulus; CS+) was followed by disgusting videos of individuals vomiting (unconditioned stimulus; US) and another neutral food item (CS-) was not reinforced with the disgusting video. Following this acquisition phase, there was an extinction phase in which both CSs were presented unreinforced. Importantly, participants also evaluated generalization stimuli (GS+, GS-) that resembled, but were distinct from, the CS after each conditioning phase. As predicted, the CS+ was rated as significantly more disgusting and fear inducing than the CS- after acquisition and this pattern persisted after extinction. However, disgust ratings of the CS+ after acquisition were significantly larger than fear ratings. Participants also rated the GS+ as significantly more disgusting, but not fear inducing, than the GS- after acquisition. However, this effect was not observed after extinction. Disgust proneness did predict a greater increase in disgust and fear ratings of the CS+ relative to the CS- after acquisition and extinction. In contrast, trait anxiety predicted only higher fear ratings to the CS+ relative to the CS- after acquisition and extinction. Disgust proneness nor trait anxiety predicted the greater increase in disgust to the GS+ relative to the GS- after acquisition. These findings suggest that while conditioned disgust can generalize, individual difference variables that predict generalization remain unclear. The implications of these findings for disorders of disgust are discussed.

Experience of Disgust and Symptom Severity in Contamination Subtype of Obsessive-Compulsive Disorder: Role of Experiential Avoidance

BACKGROUND

The emotion of disgust has been linked with the underlying nature of the contamination subtype of obsessive-compulsive disorder (C-OCD). Prior studies show that disgust contributes to the development of C-OCD by reinforcing avoidance strategies. Therefore, experiential avoidance (EA) may influence the effect between disgust sensitivity (DS) and C-OCD symptom severity. This study aimed to investigate the mediational role of EA between DS and C-OCD severity.

METHODS

A cross-sectional design was adopted with 45 patients of OCD and 45 healthy controls. Both the groups were assessed on the Obsessive-Compulsive Inventory, the Disgust Scale (Revised), and Acceptance and Action Questionnaire-II. Yale-Brown Obsessive Compulsive Scale (Y-BOCS) checklist and symptom severity scale were additionally administered to the patients with OCD. Independent t-tests, Pearson's product-moment correlation, regression analysis, and mediation analysis were used.

RESULTS

DS and EA were positively associated with contamination-washing symptoms and symptom severity. Regression analysis indicated that DS and EA were highly associated with contamination/washing severity scores among both the patients with C-OCD and the healthy controls.

CONCLUSION

The study implicates that disgust is a central emotion underlying the presentation of obsessions and compulsions, which are of contamination concerns. Further, EA has a role in the maintenance of OCD through avoidance learning; however, it may not be interacting with DS to cause OCD.

More than just fear: Development and psychometric evaluation of the Spider Distress Scale to assess spider fear and spider-related disgust

Spider fear is an excellent model to experimentally study processes in the maintenance and treatment of long-lasting fears. A valid, reliable, and practical tool to assess spider-related distress dimensionally, and to differentiate between spider-related fear and disgust in a time-sensitive manner, may help to better understand individual differences in these two emotions and to tailor treatments accordingly. We developed a concise self-report questionnaire, the Spider Distress Scale (SDS), that combines the strengths of established spider fear questionnaires and addresses their shortcomings. We explored (study 1 and 2) and confirmed (study 3) a two-factor structure of the SDS in samples from the general population (n = 370; n = 360; n = 423), recruited online via Prolific Academic from the United Kingdom, the Netherlands, and the United States. The fear and disgust factors of the SDS are highly internally consistent and the SDS has excellent test-retest reliability. We found good convergent and discriminant validity, based on self-report measures and spider behavioural approach tasks, and the SDS successfully differentiated between individuals with and without spider fear (study 4, n = 75). Our series of studies suggests that fear and disgust are functionally related, but that disgust towards spiders can be differentially assessed when focussing on unique elements of disgust-related information.

A Case for Translation From the Clinic to the Laboratory

Laboratory procedures have been used for decades as analogues for clinical processes with the goal of improving our understanding of psychological treatments for emotional disorders and identifying strategies to make treatments more effective. This research has often focused on translation from the laboratory to the clinic. Although this approach has notable successes, it has not been seamless. There are many examples of strategies that work in the laboratory that fail to lead to improved outcomes when applied clinically. One possible reason for this gap between experimental and clinical research is a failure to focus on translation from the clinic to the laboratory. Here, we discuss potential benefits of translation from the clinic to the laboratory and provide examples of how this might be implemented. We first consider two well-established laboratory analogues (extinction and cognitive reappraisal), identify critical aspects of the related clinical procedures (exposure and cognitive restructuring) that are missing from these analogues, and propose variations to better capture the clinical process. Second, we discuss two clinical procedures that have more recently been brought into the laboratory (eye-movement desensitization and reprocessing and imagery rescripting). We conclude by highlighting potential implications of this proposed shift in focus for translational research.

Gut Barrier Dysfunction and Type 2 Immunity: Implications for Compulsive Behavior

To date, much of the focus of gut-brain axis research has been on gut microbiota regulation of anxiety and stress-related behaviors. Much less attention has been directed to potential connections between gut microbiota and compulsive behavior. Here, we discuss a potential link between gut barrier dysfunction and compulsive behavior that is mediated through "type 2" rather than "type 1" inflammation. We examine connections between compulsive behavior and type 2 inflammation in Tourette syndrome, obsessive-compulsive disorder, autism, addiction, and post-traumatic stress disorder. Next, we discuss potential connections between gut barrier dysfunction, type 2 inflammation, and compulsive behavior. We posit a potential mechanism whereby gut barrier dysfunction-associated type 2 inflammation may drive compulsive behavior through histamine regulation of dopamine neurotransmission. Finally, we discuss the possibility of exploiting the greater accessibility of the gut relative to the brain in identifying targets to treat compulsive behavior disorders.

Mechanisms and Effectiveness of Imagery Strategies in Reducing Disgust in Contamination-Related Obsessive–Compulsive Disorder: Comparing Imagery Rescripting, Imagery Self-compassion and Mood-Focused Imagery

Background

Strong feelings of disgust and anxiety are maintaining factors in contamination-related obsessive–compulsive disorder (C-OCD). To this day there are not many studies that investigated strategies for changing pathological disgust. In a previous study, it was shown that imagery rescripting could successfully change disgust. However, whether imagery rescripting or more general imagery processing, helps to reduce pathological disgust, remains unclear. Therefore, the aim of the present study was to investigate how successful imagery rescripting is in comparison to imagery self-compassion and a passive positive imagery condition in reducing disgust.

Methods

For this, the three strategies were compared to each other on 2 days (within-subject) in a laboratory experiment. The study included 24 subjects with diagnosed C-OCD, and 24 matched, healthy controls (between-subject).

Results

The results show that all three strategies changed disgust, they do not differ from each other and that different traits appear to influence the strategies’ success or failure. The theoretically derived underlying mechanisms of the strategies were found in an elaborate content analysis.

Conclusions

The present study provides first indications that imagery in general can help to change pathological disgust experience.

Fear conditioning and extinction in obsessive-compulsive disorder: A systematic review

Laboratory experiments using fear conditioning and extinction protocols help lay the groundwork for designing, testing, and optimizing innovative treatments for anxiety-related disorders. Yet, there is limited basic research on fear conditioning and extinction in obsessive-compulsive disorder (OCD). This is surprising because exposure-based treatments based on associative learning principles are among the most popular and effective treatment options for OCD. Here, we systematically review and critically assess existing aversive conditioning and extinction studies of OCD. Across 12 studies, there was moderate evidence that OCD is associated with abnormal acquisition of conditioned responses that differ from comparison groups. There was relatively stronger evidence of OCD's association with impaired extinction processes. This included multiple studies finding elevated conditioned responses during extinction learning and poorer threat/safety discrimination during recall, although a minority of studies yielded results inconsistent with this conclusion. Overall, the conditioning model holds value for OCD research, but more work is necessary to clarify emerging patterns of results and increase clinical translational utility to the level seen in other anxiety-related disorders. We detail limitations in the literature and suggest next steps, including modeling OCD with more complex conditioning methodology (e.g., semantic/conceptual generalization, avoidance) and improving individual-differences assessment with dimensional techniques.

Generalization of conditioned disgust and the attendant maladaptive avoidance: Validation of a novel paradigm and effects of trait disgust-proneness

Overgeneralization of conditioned fear to safe stimuli that resemble a previously-learned threat-cue is a well-studied correlate of clinical anxiety, yet whether conditioned disgust generalizes remains unknown, as does the extent to which such generalization is associated with disgust-related traits and maladaptive outcomes. The present study addresses this gap by adapting a validated fear-generalization paradigm to assess conditioned disgust and behavioral avoidance to a disgust-cue (CS+) paired with a disgusting video clip, and safe generalization stimuli parametrically varying in perceptual similarity to CS+. For comparison, levels of fear generalization were also assessed using the original fear-generalization paradigm. In both paradigms, costly and unnecessary avoidance to safe threat-cue approximations analogues maladaptive outcomes of generalization. In the disgust paradigm only, disgust-proneness was associated with elevated perceived risk to safe stimuli and increases in the extent to which such elevations were accompanied by maladaptive avoidance. Comparable levels of generalization, and positive associations between generalization and maladaptive avoidance, were found across disgust and fear paradigms. Results confirm that conditioned disgust is subject to generalization, implicate generalized disgust as a source of maladaptive avoidance particularly among those prone to disgust, and suggest a potential role for these processes in the etiology and maintenance of disgust-related disorders.

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.

The effect of differential disgust conditioning and subsequent extinction versus counterconditioning procedures on women's sexual responses to erotic stimuli

Recent theoretical accounts point to disgust as an important factor in the development and persistence of sexual dysfunctions. This study tested if (i) contingent disgust experiences can render initially sexually arousing stimuli disgusting, and (ii) such acquired disgust responses could be best neutralized via a CS-only extinction or a counterconditioning procedure. Participants (N = 74) were exposed to a differential conditioning procedure that was followed by either a CS-only extinction or a counterconditioning procedure. Erotic films served as the CS+/CS-. A disgusting film served as the US. During the extinction procedure, the CS+ was no longer followed by the disgusting US. During counterconditioning the CS+ was paired with positive stimuli. After conditioning, the CS + elicited lower genital arousal and was rated as significantly more disgusting, less pleasant, and less sexually arousing than the CS-. These diminished genital and subjective sexual arousal responses to the CS+ were successfully restored after both the extinction and the counterconditioning procedure, whereas conditioned feelings of disgust and behavioral avoidance persisted. There was no evidence for differential effectiveness of either procedure. Thus, sexual responses can be attenuated by learned sex-disgust associations and restored by extinction and counterconditioning procedures, but conditioned feelings of disgust seem more resistant.

Interpretation bias and contamination-based obsessive-compulsive symptoms influence emotional intensity related to disgust and fear

Biased processing of disgust-related stimuli is increasingly discussed in addition to fear-related processing as a maintenance factor for contamination-based obsessive-compulsive disorder (C-OCD). However, the differential impact of fear and disgust on biased processing in C-OCD is not yet completely understood. Because it is difficult to distinguish the two emotions in self-report assessment by directly addressing the specific emotions, a text paragraph-based interpretation bias paradigm was applied to more implicitly assess emotions. For the text-based interpretation bias paradigm, disgust-related, fear-related, disgust-fear-ambiguous and neutral text paragraphs describing everyday life situations were developed and validated in a pre-study (N = 205). Fifty-nine healthy participants watched either disgust- or fear-inducing movies and afterwards rated their experienced emotional response to the text paragraphs. The results show that fear and disgust components of an emotional response to mixed-emotional situations are strongly influenced by the situational context, and across the levels of trait contamination fear people did not differ in their fear experiences to everyday situations (which was overall strong), but in their disgust experiences. These findings highlight the strength of situational context on interpretation bias for mixed-emotional disorders and the important role of disgust for C-OCD.

Linking Pavlovian Disgust Conditioning and Eating Disorder Symptoms: An Analogue Study

Although the experience of disgust is commonly endorsed among women with eating disorders, it remains unclear how to best model this emotion in relation to disordered eating. The present study sought to identify potential disgust conditioning abnormalities that may underlie the development of eating disorder symptoms. Individuals high and low in eating disorder symptoms (HED, n = 19; LED, n = 18) completed a Pavlovian conditioning procedure in which one neutral food item (conditioned stimulus; CS+) was followed by disgusting videos of individuals vomiting (unconditioned stimulus; US) and another neutral food item (CS-) was not reinforced with the disgusting video. Following this acquisition procedure, there was an extinction procedure in which both CSs were presented unreinforced. The results showed that ratings of disgust, fear, and willingness to eat the CS+ and CS- did not significantly vary as a function of the conditioning phase for the LED group. However, the HED group rated the CS+ as significantly more disgusting and fear inducing than the CS- after the acquisition phase and this pattern persisted after extinction. These conditioning effects were also observed to be significantly larger for disgust compared to fear. The HED group also reported being significantly less willing to eat the CS+ compared to the CS- after the acquisition phase and this pattern also persisted after extinction. In the full sample, only discriminant disgust responding after acquisition was associated with the amount of calorie consumption over the 24-hour period after conditioning. These findings suggest that eating disorder symptoms may result from a heightened proneness to associate disgusting outcomes with otherwise neutral food items. This pattern of disgust learning may reinforce food avoidance in eating disorders and appears to be difficult to fully unlearn.

Disgust in Anxiety and Obsessive-Compulsive Disorders: Recent Findings and Future Directions

PURPOSE OF REVIEW

In the past 20 years, the role of disgust in anxiety disorders and obsessive-compulsive disorder (OCD) has been investigated with increasing precision. In this review, we examine recent evidence implicating disgust in anxiety and OCD, highlighting recent measurement and methodological improvements. Specific emphasis is placed on understanding the mechanisms that may account for the role of disgust in OCD and related disorders.

RECENT FINDINGS

Recent developments include clarification of the role of distinct disgust-relevant vulnerabilities in the etiology of anxiety and OCD, an improved understanding of the neurobiology of disgust processing in OCD, and an increased focus on disgust-related mechanisms that contribute to psychopathology, such as disgust-based learning and emotion regulation. Disgust proneness is increasingly linked with symptoms of anxiety and OCD. However, further examination of the mechanisms that account for the roles of distinct disgust-relevant vulnerabilities is needed, and studies that directly examine disgust during the course of treatment are limited. Increasingly, the field has moved toward experimental investigation of specific disgust-relevant mechanisms that influence the etiology and treatment of OCD and related anxiety disorders.