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

Specific Contamination Symptoms are Associated with Experiencing a Limited Response of Cognitive-Behavioral Therapy in Pediatric Patients with OCD

A recent study identified three distinct treatment-response trajectories in pediatric OCD where higher levels of contamination symptoms predicted a limited response to cognitive-behavioral therapy (CBT). This study extends these findings by examining which specific symptoms characterize limited CBT response from baseline to 3-year follow-up, with an emphasis on contamination symptoms. The study sample comprised 269 pediatric patients with OCD, all receiving stepped-care treatment with manualized CBT. Differences in single item-reporting between the three trajectory groups were examined using linear mixed-effect modeling. Limited responders displayed a higher symptom load across all OCD symptom categories at 3-year follow-up, dominated by contamination symptoms. Five of these (obsessions about dirt and germs, about bodily fluids, about the feeling of contamination and compulsions regarding handwashing and showering) showed persistence from baseline to 3-year follow-up. The results indicate that presence of specific contamination symptoms may influence long-term symptom severity trajectories in young patients with OCD.

Disgust-reduction evaluative conditioning (DREC) and brain stimulation in patients with contamination-based obsessive-compulsive disorder: a protocol for a randomized control trial

BACKGROUND

The negative emotional valence of a stimulus can be altered if paired with a pleasant stimulus, a phenomenon referred to as evaluative conditioning. Disgust, as a central emotion in obsessive-compulsive disorder (OCD), particularly in the contamination subtype, may be an appropriate target for such a method. We know that disgust processing and OCD pathophysiology share in some brain areas, including the orbitofrontal cortex, as the neuromodulation techniques targeted in this area have been able to decrease OCD symptoms. We aim to conduct a randomized clinical trial to investigate the evaluative conditioning effect on disgust reduction in patients with contamination-based OCD when administered with or without neuromodulation targeted orbitofrontal cortex.

METHOD

In a single-blind randomized control trial (RCT), 55 patients with contamination-based OCD will be randomly assigned to four arms. In a factorial design, they will receive 10 sessions of evaluative conditioning training (either sham or real) plus cathodal transcranial direct current stimulation (tDCS) over the orbitofrontal cortex (either sham or real). The intensity of disgust experience and clinical symptoms will be investigated as primary outcomes and quantitative electroencephalogram and cognitive functions as secondary outcomes. The data will be collected at three assessment levels: baseline, after completing intervention sessions, and 2-month follow-up.

DISCUSSION

The present RCT is the first study that applies evaluative conditioning training in the OCD clinical sample. It will clarify the effect of the evaluative conditioning method alone and with tDCS on disgust reduction in patients with contamination-based OCD. It will provide initial evidence for such an emotion modulation method in the OCD population. The effect of this emotion-focused protocol on cognitive functions and electroencephalogram components is also of interest.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT05907369. Registered on 16 June 2023. Retrospectively registered.

Attenuating experimentally acquired disgust: Comparing counterconditioning, exposure and unconditioned stimulus revaluation

BACKGROUND AND OBJECTIVES

Disgust is implicated in the aetiology and maintenance of various psychopathologies such as anxiety disorders and obsessive-compulsive disorders. Despite its prominent role in psychopathology, little is known about how to effectively attenuate disgust. The study examined strategies to modify an experimentally acquired disgust response in a sample of undergraduate students.

METHODS

A conditioning paradigm was used where participants (N = 175) first underwent acquisition of disgust via repeated presentations of a neutral picture (functioning as conditioned stimulus + [CS+]) paired with a disgusting picture (functioning as unconditioned stimulus [US]). Participants were then randomly assigned to either an exposure (repeated presentation of CS-only trials), counterconditioning (pairing CS+ with pleasant pictures), US revaluation (pairing disgusting US with pleasant pictures) or a control (filler task) condition. We hypothesised that counterconditioning would attenuate evaluative learned disgust to the greatest extent, relative to exposure and US revaluation. Participants' evaluations of the pictures were attained with a disgust-pleasantness visual analogue scale.

RESULTS

Exposure, counterconditioning and US revaluation reduced disgusting US expectancies. However, experimental and control conditions did not differ in terms of attenuating disgust towards CS+.

LIMITATIONS

Measures of psychopathology and implicit evaluations of disgust were not collected. Modest power might have limited significance of the results.

CONCLUSIONS

No statistical support for the effectiveness of disgust attenuation following exposure nor counterconditioning were found. Findings for US revaluation are inconclusive. Implications for future research are discussed.

Exposure and Response Prevention in Virtual Reality for Patients with Contamination-Related Obsessive-Compulsive Disorder: a Case Series

Exposure therapy in virtual reality is successful in treating anxiety disorders. Studies on exposure and response prevention in virtual reality (VERP) in obsessive-compulsive disorder (OCD) are rare, and it is unclear whether distress associated with other emotions than anxiety (e.g., disgust) can be evoked. The present study aimed to investigate whether distress can be induced during VERP in patients with contamination-related OCD (C-OCD) and a primary feeling of disgust. We treated eight female patients with C-OCD with the primary emotion of disgust over six weeks with VERP and assessed their OC symptoms before and after the intervention period with the Y-BOCS. We measured subjective units of distress (SUD), heart rate and skin conductivity (arousal), sense of presence, and simulator sickness during four consecutive exposure sessions. VERP was able to induce distress and arousal. The qualitative feedback was heterogeneous and sense of presence moderate. Patients' OC symptoms reduced over the treatment period with medium to large effect sizes, but only two patients were considered responders; two patients discontinued treatment due to lack of treatment success. Although VERP was able to induce distress and arousal associated with disgust and evoked a moderate sense of presence, the low rate of symptom reduction diminishes the positive results. Possible reasons for the heterogeneous results and implications are discussed. Trial registration: German Registry for Clinical Studies (DRKS00016929), 10.04.2019.

Common and separable behavioral and neural mechanisms underlie the generalization of fear and disgust

Generalization represents the transfer of a conditioned responses to stimuli that resemble the conditioned stimulus (CS). Previous studies on generalization of defensive avoidance responses have primarily focused on fear and have neglected disgust generalization, which represents a key pathological mechanism in some anxiety disorders. In the present study we examined common and distinct mechanisms of fear and disgust generalization by means of a fear or disgust multi-CS conditioning and generalization paradigm with concomitant event-related potential (ERPs) acquisition in n = 62 subjects. We demonstrate that compared to fear, disgust-relevant generalized stimuli (GS) elicited larger expectancy ratings and longer reaction times (RTs) reflecting stronger ratings of 'risk'. On the electrophysiological level, increased P2 amplitudes were found in response to conditioned CS+ versus CS- across both domains, possibly reflecting higher motivational and attentional salience of aversive conditioned stimuli per se. Contingent negative variation (CNV) amplitude was significantly larger for disgust-CS+ than disgust-CS-, reflecting a stronger preparation of the disgust US. Additionally, we found that the contingent negative variation (CNV) fear generalization gradient, and CNV amplitude were increased with similarity to CS+. In contrast the CNV to disgust-GS did not differ and did not reflect disgust generalization. Together this may indicate that the CNV represents a highly fear-specific index for generalization learning. This study provides the first neurobiological evidence for common and distinct generalization learning in fear versus disgust suggesting that dysregulations in separable defensive avoidance mechanisms may underly different anxiety disorder subtypes.

Anti-Disgust Cognitive Behavioral Therapy for Contamination-Based Obsessive Compulsive Disorder: A Randomized Controlled Clinical Trial

Background: Disgust is a strong and persistent emotion that frequently occurs during exposure-based treatments for contamination-based obsessive compulsive disorder (C-OCD). This study aimed to examine the efficacy of augmenting cognitive behavioral therapy (CBT) with a novel type of anti-disgust cognitive intervention in reducing the severity of OCD, disgust propensity/sensitivity, and refusal rate of exposure and response prevention, while simultaneously increasing acceptance of disgust. Materials and Methods: Fifty-five individuals with C-OCD (mean age 28.1 years, SD = 3.52; 77% female) were randomly assigned to 15 weekly sessions of anti-disgust plus CBT (AD-CBT) or CBT alone. They were evaluated for outcomes four times (pretreatment, prior to exposure and response prevention (ERP) sessions, posttreatment, and three-month follow-up), and mixed-design ANOVAs were used to analyze the data. Results: The findings indicated that when compared to CBT alone, AD-CBT significantly reduced OCD severity, disgust propensity/sensitivity, and concurrently increased disgust acceptance (p < 0.001). Additionally, engaging in an anti-disgust cognitive intervention was associated with lower ERP refusal rate (4% vs. 16%). The superiority of AD-CBT over CBT persisted through the three-month follow-up period. Conclusions: The current study suggests that supplementing CBT for C-OCD with an anti-disgust cognitive intervention significantly increased acceptance of disgust and decreased the refusal rate of ERP, OCD severity, and disgust-related factors.

Obsessive-compulsive disorder-contamination fears, features, and treatment: novel smartphone therapies in light of global mental health and pandemics (COVID-19)

This review aims to shed light on the symptoms of obsessive-compulsive disorder (OCD) with a focus on contamination fears. In addition, we will briefly review the current therapies for OCD and detail what their limitations are. A key focus will be on discussing how smartphone solutions may provide approaches to novel treatments, especially when considering global mental health and the challenges imposed by rural environments and limited resources; as well as restrictions imposed by world-wide pandemics such as COVID-19. In brief, research that questions this review will seek to address include: (1) What are the symptoms of contamination-related OCD? (2) How effective are current OCD therapies and what are their limitations? (3) How can novel technologies help mitigate challenges imposed by global mental health and pandemics/COVID-19.

Is Acquired Disgust More Difficult to Extinguish Than Acquired Fear? an Event-Related Potential Study

This study used the classical conditioned acquisition and extinction paradigm to compare which of the two emotions, acquired disgust and acquired fear, was more difficult to extinguish, based on behavioral assessments and the event-related potential (ERP) technique. Behavioral assessments revealed that, following successful conditioned extinction, acquired disgust was more difficult to extinguish. The ERP results showed that, at the early stage of P1, the amplitude of conditioned fear was significantly smaller than that of conditioned disgust, and both were significantly different from the amplitude under neutral conditions; at the middle stage of N2, the difference between the amplitudes of conditioned disgust and conditioned fear disappeared, but they were still significantly different from the amplitudes of conditioned neutral stimuli; at the late stage of P3, the difference between conditioned disgust and conditioned neutral stimuli disappeared, but the difference between conditioned fear and neutral stimuli remained, suggesting that acquired fear was more difficult to extinguish than acquired disgust in terms of how the brain works.

The Impact of COVID-19 Pandemic on Obsession and Compulsion Symptoms in Saudi Arabia

Background

Obsessive-compulsive disorder (OCD) is a common condition that has a significant impact on people’s lives. COVID-19 pandemic imposed a challenging situation for the general population with new precautionary measures. All that can have serious implications for those who already have intense concerns about cleanliness and hygiene and those diagnosed with OCD. The aim of this study was to examine the impact of the coronavirus disease 2019 (COVID-19) pandemic on the emergence and severity of obsession and compulsion symptoms in Saudi Arabia.

Methods

This was a cross-sectional study with 1,190 participants who completed an online three-part questionnaire that included sociodemographic data, the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS) checklist, and (Y-BOCS) severity scale. On account of the fact that OCD requires a clinical evaluation to confirm the diagnosis, screening positive for OCD was defined based on criteria A of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which is selecting at least one of either obsession or compulsion symptoms or both. Screening positive for obsession was defined as selecting at least one of the obsessional symptoms while screening positive for compulsion was defined as selecting at least one of the compulsion symptoms.

Results

Overall, OCD screening was positive in 82% of participants. Previous diagnosis of OCD was reported by 2.6% (N=36) of the participants and 55.2% of them reported that their symptoms did not change during the pandemic, while 41.1% reported that their symptoms increased. Positive OCD screening was significantly higher in participants who reported previous psychological illness (87.6% vs. 80.9%), those who followed news related to COVID-19 on a daily basis (88.7% vs. 76.1%), and participants who had not acquired the infection (82.9%) compared to those who were infected with COVID-19 (72.3%).

Conclusion

The aim of this study was to determine the impact of the pandemic on OCD screening and symptoms. New OCD symptoms were reported in a high proportion of the participants. The results of this study can provide guidance for psychiatrists and psychologists in the clinical approach and management of patients with OCD. Further focused research on the factors affecting the emergence or severity of OCD symptoms needs to be conducted in the future.

Knowledge and competency standards for specialized cognitive behavior therapy for adult obsessive-compulsive disorder

Obsessive-Compulsive Disorder (OCD) is a leading cause of disability world-wide (World Health Organization, 2008). Treatment of OCD is a specialized field whose aim is recovery from illness for as many patients as possible. The evidence-based psychotherapeutic treatment for OCD is specialized cognitive behavior therapy (CBT, NICE, 2005, Koran and Simpson, 2013). However, these treatments are not accessible to many sufferers around the world. Currently available guidelines for care are deemed to be essential but insufficient because of highly variable clinician knowledge and competencies specific to OCD. The phase two mandate of the 14 nation International OCD Accreditation Task Force (ATF) created by the Canadian Institute for Obsessive Compulsive Disorders is development of knowledge and competency standards for specialized treatments for OCD through the lifespan deemed by experts to be foundational to transformative change in this field. This paper presents knowledge and competency standards for specialized CBT for adult OCD developed to inform, advance, and offer a model for clinical practice and training for OCD. During upcoming ATF phases three and four criteria and processes for training in specialized treatments for OCD through the lifespan for certification (individuals) and accreditation (sites) will be developed based on the ATF standards.

Acquisition and maintenance of disgust reactions in an OCD analogue sample: Efficiency of extinction strategies through a counter-conditioning procedure

BACKGROUND

Obsessive-compulsive disorder (OCD) has long been considered as an anxiety disorder, disgust is the dominant emotion in contamination-based OCD. However, disgust seems resistant to exposure with response prevention partly due to the fact that disgust is acquired through evaluative conditioning.

AIMS

The present research investigates a counter-conditioning intervention in treating disgust-related emotional responses in two groups of individuals with high (High contamination concerns, HCC, n = 24) and low (Low contamination concerns LCC, n = 23) contamination concerns.

METHODS

The two groups completed a differential associative learning task in which neutral images were followed by disgusting images (conditioned stimulus; CS+), or not (CS-). Following this acquisition phase, there was a counter-conditioning procedure in which CS+ was followed by a very pleasant unconditional stimulus while CS- remained unreinforced.

RESULTS

Following counter-conditioning, both groups reported significant reduction in their expectancy of US occurrence and reported less disgust with CS+. For both expectancy and disgust, reduction was lower in the HCC group than in the LCC group. Disgust sensitivity was highly correlated with both acquisition and maintenance of the response acquired, while US expectation was predicted by anxiety.

CONCLUSION

Counter-conditioning procedure reduces both expectations and conditioned disgust.

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.

The Role of Disgust and Threat in Contamination-Related Obsessive–Compulsive Disorder

Theoretical models suggest that the emotion disgust or threat overestimates are important in the aetiology and maintenance of contamination-based obsessive–compulsive disorder. In the current study, both threat and disgust were manipulated and 115 non-clinical participants (mean age 20.46 years, 94 females) were randomly allocated to one of four conditions: high-disgust/low-threat (n = 29), high-disgust/high-threat (n = 29), low-disgust/low-threat (n = 27), and low-disgust/high-threat (n = 30). Participants completed a hierarchical Behavioural Avoidance Task (BAT). Those in the high-threat and high-disgust conditions completed less BAT steps and showed more latency to begin each step than those in the low-threat and low-disgust conditions. A significant interaction effect was observed for the high-disgust/high-threat condition as significantly more task avoidance was found. However, handwashing duration was not significantly different between the high and low-disgust conditions or the high and low-threat conditions. The overall low mean washing duration of 30 s possibly due to the testing conditions and/or the ethnic heterogeneity of the sample may account for these results. There were also no significant differences in the level of anxiety for participants in the high-threat compared with the low-threat conditions. It is possible that anxiety remained relatively low across conditions as a result of the graduated BAT. Future research and theoretical and clinical implications 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.

Inducing and manipulating sensations of incompleteness

Incompleteness (INC) and Harm Avoidance (HA) are known core dimensions of obsessive-compulsive disorder (OCD). Emotional processing and inhibitory learning (IL) have both been proposed as viable mechanisms of exposure for the alleviation of HA, yet the relationship with INC remains unclear. This study evaluated differential manipulation responses to induced INC. The authors specifically tested whether targeting the key component of IL, expectancy violation generated by the discrepancy between an articulated prediction and the actual exposure experience, would lead to improved outcomes. A sample of undergraduates (N = 68) completed a series of behavioral tasks to induce INC, followed by manipulations (exposure with or without articulated predictions) to reduce INC reactions. Results show that modest changes were observed following reduction manipulations following INC induction. Furthermore, heightened HA predicted the changes of induced sensations. Mediation tests showed that articulation of predicted sensations mediated pre- to postreduction ratings. Clinical and research implications are discussed.

Eligible blood donors' decisions about donating stool for fecal microbiota transplantation: Does ambivalence play a role?

Blood collection agencies (BCAs) are expanding core business by inviting blood donors to donate stool for fecal microbiota transplantation (FMT). However, whether blood donors also want to donate stool is unclear since, despite its benefits, stool donation is viewed by many as unpleasant. This study examined the prevalence, contributors to, and role of these mixed feelings (ambivalence) in stool donation intentions.

STUDY DESIGN AND METHODS

This cross-sectional study surveyed Australian residents aged 18 years or more who believed themselves eligible to donate blood and met broad criteria for prescreening as a stool donor (eg, healthy, not taking medication). Survey questions assessed attitude, norms, self-efficacy, motives, disgust, ambivalence, and intentions to donate stool.

RESULTS

A total of 382 eligible blood donors aged not more than 50 years (mean, 28.71 years; 48% female, 62% "healthy" body mass index) participated. Six percent indicated no ambivalence about donating stool. In regression, significant determinants of ambivalence were less awareness of FMT, lower self-efficacy, motivated by ensuring that stool is available for loved ones, and more disgust about stool donation. Higher ambivalence contributed to decreased donation intention. Self-efficacy and disgust differentiated participants with moderate ambivalence, a group likely responsive to intervention, from those with low or high ambivalence.

CONCLUSION

Ambivalence about donating stool was common among eligible blood donors. BCAs should raise awareness about stool donation and FMT before requesting donation. BCAs may increase cost savings and donor retention by giving clear guidance about donation requirements and implementing processes that build confidence. Early screening of potential donors for ambivalence and disgust will enable BCAs to provide decision support.

A Meta-Analysis on the Efficacy of Exposure-Based Treatment in Anxiety Disorders: Implications for Disgust

Despite of several meta-analyses indicating that exposure-based treatments (EBT) are successful in addressing anxiety and fear symptoms, less is known whether this is also the case for disgust, which also accompanies anxiety disorders. Therefore, the aim of the current meta-analysis was to compare the efficacy of EBT on disgust and anxiety (emotional distress), against control condition. This meta-analysis included a total of eight studies. Overall, there was a medium effect size (g = .57, 95% CI: .26 to .88, p < .001) for emotional distress; a medium effect size for anxiety (g = .79, 95% CI: .24 to 1.34, p = .005), yet a small effect size for disgust (g = .36, 95% CI: .05 to .68, p = .024). These findings prompt that current EBT are not tailored to address disgust symptoms accompanying many forms of anxiety disorders, although literature points more and more to a need in this respect. We also examined potential moderator variables (the year of publication, the number of exposure sessions, age of the sample, and gender composition). Additionally, we discussed several strengths and limitations, one of the most important being the small number of studies regarding the subject and their heterogeneity.

Modulating disgust in mental contamination: Experimental evidence for the role of disgust

BACKGROUND AND OBJECTIVES

Disgust has been associated with mental contamination (MC), although the evidence has hitherto been nonexperimental. Furthermore, strategies that can target both disgust and MC have not been well explored. We investigated the role of disgust in MC by inducing disgust via olfaction within the "dirty kiss" paradigm and conversely, to see if pairing pleasant olfactory stimulus during re-exposure, based on counterconditioning, can reduce MC. We also examined whether disgust constructs (propensity and sensitivity) and trait MC are associated with state MC arising from the "dirty kiss".

METHODS

MC was first evoked using the "dirty kiss" paradigm, in which participants (N = 90) visualized receiving a non-consensual kiss from a physically dirty man (time 1). After a break, participants repeated the "dirty kiss" task in a room that was scented to smell either disgusting, pleasant or neutral (time 2). Participants completed measures of disgust and trait MC after the experiment.

RESULTS

Participants in the disgust condition reported increased feelings of dirtiness at time 2. Disgust propensity predicted feelings of dirtiness at time 1. Disgust sensitivity and trait MC were not associated with state MC indices.

LIMITATIONS

The use of a non-clinical female sample, extraneous factors during the break and contextual factors arising from room change at time 2 are some potential limitations.

CONCLUSIONS

Induced disgust within a MC paradigm resulted in increased feelings of dirtiness, suggestive of disgust-based emotional reasoning. Pairing pleasant olfactory stimulus was not effective at attenuating MC or disgust.

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.

Behavioral and neural processes in counterconditioning: Past and future directions

Counterconditioning refers both to the technique and putative process by which behavior is modified through a new association with a stimulus of an opposite valence. Similar to extinction, counterconditioning is considered a form of inhibition that interferes with the expression of the originally learned response without erasing it. But whereas interest in extinction continues to rise, counterconditioning has received far less attention. Here, we provide an in-depth review of counterconditioning research and detail whether counterconditioning is any more effective than extinction at preventing relapse of the originally learned behavior. We consider the clinical implications of counterconditioning, describe recent neurobiological and neuroimaging research in this area, and consider future avenues in need of further investigation.

"Fake it till You Make it"! Contaminating Rubber Hands ("Multisensory Stimulation Therapy") to Treat Obsessive-Compulsive Disorder

Obsessive-compulsive disorder (OCD) is a deeply enigmatic psychiatric condition associated with immense suffering worldwide. Efficacious therapies for OCD, like exposure and response prevention (ERP), are sometimes poorly tolerated by patients. As many as 25% of patients refuse to initiate ERP mainly because they are too anxious to follow exposure procedures. Accordingly, we proposed a simple and tolerable (immersive yet indirect) low-cost technique for treating OCD that we call “multisensory stimulation therapy.” This method involves contaminating a rubber hand during the so-called “rubber hand illusion” (RHI) in which tactile sensations may be perceived as arising from a fake hand. Notably, Jalal et al. (2015) showed that such fake hand contamination during the RHI provokes powerful disgust reactions in healthy volunteers. In the current study, we explored the therapeutic potential of this novel approach. OCD patients (n = 29) watched as their hidden real hand was being stroked together with a visible fake hand; either synchronously (inducing the RHI; i.e., the experimental condition; n = 16) or asynchronously (i.e., the control condition; n = 13). After 5 min of tactile stimulation, the rubber hand was contaminated with fake feces, simulating conventional exposure therapy. Intriguingly, results suggested sensory assimilation of contamination sensations into the body image via the RHI: patients undergoing synchronous stimulation did not report greater contamination sensations when the fake hand was initially contaminated relative to asynchronous stroking. But contrary to expectations, they did so after the rubber hand had been contaminated for 5 min, as assessed via disgust facial expressions (a secondary outcome) and in vivo exposure (upon discontinuing the illusion). Further, to our surprise, synchronous and asynchronous stroking induced an equally vivid and fast-emerging illusion, which helps explain why both conditions initially (5 min after initiating tactile stimulation) provoked contamination reactions of equal magnitude. This study is the first to suggest heightened malleability of body image in OCD. Importantly, it may pave the way for a tolerable technique for the treatment of OCD—highly suitable for poorly resourced and emergency settings, including low-income and developing countries with minimal access to high-tech solutions like virtual reality.

Disgust and the rubber hand illusion: a registered replication report of Jalal, Krishnakumar, and Ramachandran (2015)

Heightened experience of disgust is a feature of obsessive-compulsive disorder (OCD), particularly contamination-related OCD (C-OCD). Previous studies of the rubber hand illusion (RHI) reported that the sense of body ownership is related to the interaction between vision, touch, and proprioception. One recent study demonstrated a link between the RHI and disgust, suggesting that there is an interaction between these three perceptual modalities and disgust (Jalal et al., PLOS ONE 10:e0139159, 2015). However, there have been no direct replications of this initial study. We therefore performed a direct replication of Jalal et al.'s (PLOS ONE 10:e0139159, 2015) study. We examined 133 participants (based on a power analysis) to determine whether placing contamination-related stimuli on a rubber hand causes OCD-like disgust among healthy participants experiencing the RHI. That is, we tested whether Japanese participants experience more intense disgust when the rubber hand and the participant's hidden hand are stroked synchronously than when stroked asynchronously, in order to replicate and examine the cross-cultural validity of this effect. The main finding of the original study by Jalal and colleagues was successfully replicated in a large sample. Some inconsistencies in one of the control procedures exploring coldness sensations during the RHI were found, which could possibly be due to cross-cultural differences or the improved statistical power of the present study. Based on the present replication study, we conclude that an intervention using the RHI as proposed by Jalal et al. (PLOS ONE 10:e0139159, 2015) might potentially be useful for the treatment of OCD following replications in clinical OCD populations. Preregistration details: This study was preregistered with Cognitive Research: Principles and Implications. The Authors' protocol received in-principle acceptance on 31 March 2017. The preregistered protocol is available here: 10.6084/m9.figshare.6217295.

Responsibility/Threat Overestimation Moderates the Relationship Between Contamination-Based Disgust and Obsessive-Compulsive Concerns About Sexual Orientation

Disgust has been shown to perform a "disease-avoidance" function in contamination fears. However, no studies have examined the relevance of disgust to obsessive-compulsive (OC) concerns about sexual orientation (e.g., fear of one's sexual orientation transforming against one's will, and compulsive avoidance of same-sex and/or gay or lesbian individuals to prevent that from happening). Therefore, we investigated whether the specific domain of contamination-based disgust (i.e., evoked by the perceived threat of transmission of essences between individuals) predicted OC concerns about sexual orientation, and whether this effect was moderated/amplified by obsessive beliefs, in evaluation of a "sexual orientation transformation-avoidance" function. We recruited 283 self-identified heterosexual college students (152 females, 131 males; mean age = 20.88 years, SD = 3.19) who completed three measures assessing disgust, obsessive beliefs, and OC concerns about sexual orientation. Results showed that contamination-based disgust (β = .17), responsibility/threat overestimation beliefs (β = .15), and their interaction (β = .17) each uniquely predicted OC concerns about sexual orientation, ts = 2.22, 2.50, and 2.90, ps < .05. Post hoc probing indicated that high contamination-based disgust accompanied by strong responsibility/threat overestimation beliefs predicted more severe OC concerns about sexual orientation, β = .48, t = 3.24, p < .001. The present study, therefore, provided preliminary evidence for a "sexual orientation transformation-avoidance" process underlying OC concerns about sexual orientation in heterosexual college students, which is facilitated by contamination-based disgust, and exacerbated by responsibility/threat overestimation beliefs. Treatment for OC concerns about sexual orientation should target such beliefs.

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.

Generalization of Extinguished Fear to Untreated Fear Stimuli after Exposure

Exposure therapy is highly effective in treating excessive fear related to specific objects and/or situations. However, patients with anxiety disorders often display a generalization of fear responses toward conceptually and perceptually related stimuli and situations. It is unclear whether the beneficial effects of exposure on fear reduction toward treated fear stimuli can extend to untreated fear stimuli. Here, we investigated whether basic principles of extinction generalization apply to exposure. Spider-phobic participants were randomly assigned to either two sessions of exposure treatment (n=23) with spiders or no-treatment (n=24). Prior to and after treatment, behavioral approach tests (BATs) were conducted to examine avoidance, fear and disgust responses toward the treated phobic stimulus (spider as the extinction stimulus). Likewise, BATs with the untreated fear stimulus (cockroach) were conducted to dissect the generalization of treatment effects. Treatment was highly effective in increasing approach behavior toward both treated and untreated fear stimuli. Generalization of treatment effects were evident on the behavioral (approach distance during the BAT), subjective (fear levels during the BAT) and psychophysiological level (heart rate during the BAT). However, a stronger decline in disgust was only evident for the treated fear stimulus. Notably, the herein attained generalization effects were not context-dependent. Hence, exposure therapy for spider phobia was effective in reducing fear of untreated stimuli which share common fear-evoking characteristics with spiders but were never presented during the respective exposure treatment. These findings provide clinical evidence for extinction generalization across different fear-evoking stimuli mediated via exposure.

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.

Expanding exposure-based interventions for eating disorders

Initial trials evaluating exposure-based interventions for eating disorders (EDs) in the 1980s demonstrated mixed results. Since that time, innovations in exposure therapy for anxiety disorders have yielded insights that can be used to refine and expand the approach to effectively target ED behaviors. This article provides a brief summary of relevant advances in exposure therapy for anxiety and outlines how these advances may be adapted and evaluated for use with ED samples. More specifically, we propose shifting to an inhibitory learning framework, considering treatment targets other than fear, and increasing variability in exposure techniques represent three important areas for future study. Overall, this article aims to provide professionals in the field with a framework for how to incorporate cutting-edge advances in exposure therapy into rigorous intervention research for EDs.

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.

Cognitive behavioral therapy is effective in misophonia: An open trial

BACKGROUND

Misophonia is a psychiatric disorder in which ordinary human sounds like smacking or chewing provoke intense anger and disgust. Despite the high burden of this condition, to date there is no evidence-based treatment available. In this study we evaluated the efficacy of cognitive behavioral therapy (CBT) and investigated whether clinical or demographic characteristics predicted treatment response.

METHODS

Ninety patients with misophonia received eight bi-weekly group CBT sessions. Treatment response was defined as a Clinical Global Impression - Improvement Scale (CGI-I) score at endpoint of 1 or 2 (very much or much improved) and a 30% or greater reduction on the Amsterdam Misophonia Scale (A-MISO-S), a measure of the severity of misophonia symptoms.

RESULTS

Following treatment 48% (N=42) of the patients showed a significant reduction of misophonia symptoms. Severity of misophonia and the presence of disgust were positive predictors of treatment response.

LIMITATIONS

The A-MISO-S is not a validated scale. Furthermore, this was an open-label study with a waiting list control condition.

CONCLUSIONS

This is the first treatment study for misophonia. Our results suggest that CBT is effective in half of the patients.

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.

Factor Structure, Reliability, and Validity of the Japanese Version of the Disgust Propensity and Sensitivity Scale-Revised

The Disgust Propensity and Sensitivity Scale-Revised is one of the most widely used measures of individual differences for the emotion of disgust. It consists of 2 subscales: disgust propensity and disgust sensitivity. This study examined the factor structure, reliability, and validity of the Japanese version of the revised Disgust Propensity and Sensitivity Scale. Japanese participants (N = 1067) completed the scale as well as the Padua Inventory, Anxiety Sensitivity Index, State-Trait Anxiety Inventory, and Positive and Negative Affective Schedule. The participants were divided into 3 samples: Sample 1 (n = 481, mean age = 23.05, 186 males and 295 females); Sample 2 (n = 492, mean age = 20.27, 243 males and 249 females); and Sample 3 (n = 94, mean age = 22.68, 35 males and 58 females). We combined Samples 1 and 2 (n = 973, mean age = 21.66, 429 males and 544 females), and then created 2 subsamples to ensure the mutual independence of the samples used for two different factor analyses: subsample 1 (n = 486, mean age = 21.86, 199 male and 287 female) for exploratory factor analysis and subsample 2 (n = 487, mean age = 21.40, 230 male and 257 female) for confirmatory factor analysis. We examined test-retest reliability using Sample 3, and construct validity using Samples 1, 2, and the combined sample. Exploratory and confirmatory factor analyses revealed that the item-factor structure of the Japanese Disgust Propensity and Sensitivity Scale-Revised was identical to the English version. Moreover, the scale showed good internal consistency, test-retest reliability, and construct validity for empirical support as provided by correlational analyses. Results revealed adequate psychometric properties of the scale. This study provided the first examples of empirical support for the DPSS-R-J.

Changes in disgust and heart rate during exposure for Obsessive Compulsive Disorder: A case series

BACKGROUND AND OBJECTIVES

The emotion of disgust has been suggested as a factor contributing to a poor response to Cognitive Behaviour Therapy (CBT) in the treatment of Obsessive Compulsive Disorder (OCD). However, only limited information is available about the phenomenology of disgust in clinical OCD and the physiological mechanisms involved. This case series was designed to explore the phenomenology of OCD and the physiological activity associated with the emotion of disgust.

METHODS

State disgust and heart rate was measured in eleven participants attending treatment for OCD during exposure relevant to their individual formulation.

RESULTS

All participants with contamination and most patients with blood and injury related fears experienced a prominent increase in state disgust during exposure. These participants also had absent heart rate acceleration during exposure. Disgust response correlated with heart rate response (r = -0.63, p < 0.01) and Root Mean Square of Successive Differences (RMSSD) (r = 0.52, p < 0.01).

LIMITATIONS

The design using ecologically valid stimuli and the limited number of participants did not allow between subject comparisons or more detailed analysis of relationship between trait and state disgust and between disgust and severity of OCD.

CONCLUSIONS

Our findings show that a large proportion of our case series with OCD experience prominent disgust with signs of increased vagal tonus during their exposure. Such experiences differ from the concept of adrenergic activation used for psychoeducation in CBT and appraisals of harm and this may result in poorer therapeutic outcome.

A Framework for Understanding the Emerging Role of Corticolimbic-Ventral Striatal Networks in OCD-Associated Repetitive Behaviors

Significant interest in the mechanistic underpinnings of obsessive-compulsive disorder (OCD) has fueled research on the neural origins of compulsive behaviors. Converging clinical and preclinical evidence suggests that abnormal repetitive behaviors are driven by dysfunction in cortico-striatal-thalamic-cortical (CSTC) circuits. These findings suggest that compulsive behaviors arise, in part, from aberrant communication between lateral orbitofrontal cortex (OFC) and dorsal striatum. An important body of work focused on the role of this network in OCD has been instrumental to progress in the field. Disease models focused primarily on these regions, however, fail to capture an important aspect of the disorder: affective dysregulation. High levels of anxiety are extremely prevalent in OCD, as is comorbidity with major depressive disorder. Furthermore, deficits in processing rewards and abnormalities in processing emotional stimuli are suggestive of aberrant encoding of affective information. Accordingly, OCD can be partially characterized as a disease in which behavioral selection is corrupted by exaggerated or dysregulated emotional states. This suggests that the networks producing OCD symptoms likely expand beyond traditional lateral OFC and dorsal striatum circuit models, and highlights the need to cast a wider net in our investigation of the circuits involved in generating and sustaining OCD symptoms. Here, we address the emerging role of medial OFC, amygdala, and ventral tegmental area projections to the ventral striatum (VS) in OCD pathophysiology. The VS receives strong innervation from these affect and reward processing regions, and is therefore poised to integrate information crucial to the generation of compulsive behaviors. Though it complements functions of dorsal striatum and lateral OFC, this corticolimbic-VS network is less commonly explored as a potential source of the pathology underlying OCD. In this review, we discuss this network's potential role as a locus of OCD pathology and effective treatment.