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

A neurofunctional signature of subjective disgust generalizes to oral distaste and socio-moral contexts

While disgust originates in the hard-wired mammalian distaste response, the conscious experience of disgust in humans strongly depends on subjective appraisal and may even extend to socio-moral contexts. Here, in a series of studies, we combined functional magnetic resonance imaging with machine-learning-based predictive modelling to establish a comprehensive neurobiological model of subjective disgust. The developed neurofunctional signature accurately predicted momentary self-reported subjective disgust across discovery (n = 78) and pre-registered validation (n = 30) cohorts and generalized across core disgust (n = 34 and n = 26), gustatory distaste (n = 30) and socio-moral (unfair offers; n = 43) contexts. Disgust experience was encoded in distributed cortical and subcortical systems, and exhibited distinct and shared neural representations with subjective fear or negative affect in interoceptive-emotional awareness and conscious appraisal systems, while the signatures most accurately predicted the respective target experience. We provide an accurate functional magnetic resonance imaging signature for disgust with a high potential to resolve ongoing evolutionary debates.

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.

Mediation analyses of longitudinal data investigating temporal associations between inflated sense of responsibility, obsessive-compulsive symptoms, and anger suppression

OBJECTIVE

Cognitive theories emphasize the central role of anger and anger suppression in obsessive-compulsive disorder (OCD). According to these theories, anger suppression is seen as a consequence of OCD, whereas cognitive beliefs, such as an inflated sense of responsibility, are seen as antecedent factors. To extend the findings from cross-sectional studies, the current study investigated the temporal associations between OCD symptoms, an inflated sense of responsibility, and anger suppression. Consistent with cognitive considerations, we hypothesized that OCD symptoms mediate the association between feelings of responsibility and anger suppression. These associations were also explored in patients presenting particularly high checking-related symptoms. Further, the stability of effects beyond controlling for depressive symptoms and medication intake was explored.

METHODS

A total of N = 48 patients with OCD (50% female, M = 32.46 [SD = 10.63] years of age) completed measures on obsessive beliefs, OCD symptoms, and anger suppression at three assessment points: before and after a metacognitive intervention as well as at a follow-up 6 months later. Mediation models investigating symptom associations at these three timepoints were conducted. Exploratory analyses investigating these associations in individuals presenting high checking-related symptoms (n = 20) and testing the stability of effects beyond controlling for depressive symptoms and medication intake were conducted.

RESULTS

The sense of responsibility did not significantly predict the level of anger suppression. A temporal association between OCD symptoms (as assessed with the self-report measure) and anger suppression could be evidenced, which was stable beyond controlling for depressive symptoms and medication intake. Against the expectations based on cognitive theories, the sense of responsibility did not predict OCD symptoms. No mediating effect of OCD symptoms was found.

CONCLUSION

In line with cognitive viewpoints, the present study shows that higher OCD symptoms predict higher levels of anger suppression in a longitudinal design, thereby contributing to the suppression of anger. This effect seems to be independent from depressive symptoms and medication intake. The effect of sense of responsibility on OCD symptoms was less clear and could only be found in the subgroup of patients with OCD and checking-related symptoms, who generally presented higher levels of responsibility. Overall, this is the first study demonstrating temporal associations between OCD symptoms and anger suppression. Acknowledging that anger and anger suppression may be a consequence of OCD symptoms and may also affect aspects of psychotherapy, which can ultimately inform future adjustments to psychotherapeutic treatment.

Contamination-Focussed Vignettes as an Analogue of Infectious Pandemics: An Experimental Validation using the State Disgust and Anxiety Responses in OCD

Despite infectious pandemics proving particularly detrimental to those with Obsessive-Compulsive Disorder (OCD), the investigation of analogous experimental paradigms is lacking. To address this gap, we conducted two studies employing vignettes that depicted contamination-related situations commonly experienced during a pandemic (e.g., Coughing into hands and failing to use hand sanitizer). We manipulated the salience of these vignettes across three levels: high contamination, low contamination, and a neutral control condition. Our examination of state anxiety and disgust responses in all participants revealed the successful manipulation of the vignettes' impact. Specifically, individuals with more severe OCD symptoms reported significantly higher levels of state disgust and anxiety for both high and low contamination vignettes, in contrast to the group with lower symptom severity. No significant differences were observed in the neutral vignette condition between the high- and low-scoring groups. Interestingly, for those with higher OCD symptoms, high salience contamination-focused vignettes resulted in similarly elevated state disgust and anxiety, regardless of whether the vignettes were situated in public (Study 1) or domestic (Study 2) settings. This suggests that the heightened sensitivity to contamination-related scenarios observed in individuals with OCD symptoms in the present study is not confined to a specific context. These findings support the use of contamination-focused vignettes as analogues for studying infectious pandemics and provide valuable insights into OCD models, interventions, and future research.

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.

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.

Obsessive-compulsive existential type: a dialectical-phenomenological approach

The clinical presentation of obsessive-compulsive patients is characterized by unwanted, intrusive, nonsensical, self-related, and recurrent ideas, thoughts, images, or impulses associated with active compulsive compensations. Under the operational diagnostic criteria adopted by the biological- and cognitive-oriented neopositivist medical paradigm, it is known as "obsessive-compulsive disorder." However, this paradigm has been criticized for its controversial assumptions, limited methodologies, theoretic biases, and inconsistency in producing practical outcomes. To bypass some of these issues, we propose a complementary approach that draws on and further develops existing psychopathological studies of the obsessive-compulsive anthropological condition based on dialectical phenomenological psychopathology. As such, we refer to the global clinical configuration as the "obsessive-compulsive existential type." Our theoretical inspiration comes from the classical phenomenological work on obsessions undertaken by Straus and Gebsattel, which identified the negative transformation of the obsessive-compulsive life-world or the endogenous emergence of the anti-eidos (diluting existential force). We then propose to broaden the concept of anti-eidos, especially in its dialectical correlation with eidos (unifying existential force), representing the existential dialectic between transformation and permanence. Next, we detail the dynamics of anthropological disproportions in obsessive-compulsive existential type, essentially the supremacy of the anti-eidos over the eidos. This primary imbalance modifies the obsessive-compulsive existential structure, consisting of polymorphic temporality; weakened intentionality; maladjusted calibration of distance with the world and others; an integral, isolated, besieged self with dwindling self-agency, and tense and over-protecting embodiment. We also analyze compensatory hyperreflexivity and compulsive rituals as expressions of structural counterbalancing designed to contain the primary structural disproportions and derangements. The heterogeneous obsessive-compulsive clinical manifestations are the complex result of the primary structural alteration and subsequent phenomenological compensations. They tend to be variable in temporal span and rarely assume a fixed form, hindering diagnosis. We correlate structural frameworks with multiple clinical examples. Finally, we raise some insights on how our study may contribute to scientific research and therapeutic proposals.

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.

Design and validation of virtual environments for the treatment of cleaning obsessive-compulsive disorder

During the coronavirus outbreak, it was noted that pre-existing psychological illnesses worsened, and numerous research indicate that those with contamination-related obsessions and cleaning compulsions (C-OCD) may be more affected. Virtual Reality (VR) and other immersive technologies have shown to be effective for the treatment of disorders related to anxiety, thus showing their potential to transform OCD treatment by means of integrating virtual elements. VR exposure has shown benefits compared to live or imagined exposure, however, to be effective it must be able to elicit high emotional arousal in users. Based on this, the present work aimed to develop different virtual environments scenarios and evaluate their efficacy in generating an emotional response in people with C-OCD symptoms. Based on the literature review, two virtual scenarios were created (dirty public bathroom and unhygienic kitchen). Subsequently, two groups were then constituted: C-OCD group (n = 20, aged between 18 and 48 years) characterized by an obtained score of more than 13 points (cut-point) in the Yale-Brown Scale for Obsessive-Compulsive Disorder (Y-BOCS) and by showing C-OCD symptoms when doing the structured interview (SCID-I), and a control group (n = 20, aged between 18 and 56 years), all participants were residents of the Dominican Republic. Exposure to the virtual environments generated high levels of state and subjective anxiety in both groups, although significantly higher in the C-OCD group. The results obtained indicate that the VR scenarios developed are suitable for eliciting emotional responses and, consequently, that they can be used to complement the treatment of C-OCD.

Sympathy-Empathy and the Radicalization of Young People

BACKGROUND

The sympathy-empathy (SE) system is commonly considered a key faculty implied in prosocial behaviors, and SE deficits (also called callous-unemotional traits, CUTs) are associated with nonprosocial and even violent behaviors. Thus, the first intuitive considerations considered a lack of SE among young people who undergo radicalization. Yet, their identification with a cause, their underlying feelings of injustice and grievance, and the other ways in which they may help communities, suggest that they may actually have a lot of empathy, even an excess of it. As a consequence, the links between SE and radicalization remain to be specified. This critical review aims to discuss whether and how SE is associated with developmental trajectories that lead young people to radicalization.

METHOD

We first recall the most recent findings about SE development, based on an interdisciplinary perspective informed by social neuroscience. Then, we review sociological and psychological studies that address radicalization. We will critically examine the intersections between SE and radicalization, including neuroscientific bases and anthropologic modulation of SE by social factors involved in radicalization.

RESULTS

This critical review indicates that the SE model should clearly distinguish between sympathy and empathy within the SE system. Using this model, we identified three possible trajectories in young radicalized individuals. In individuals with SE deficit, the legitimization of violence is enough to engage in radicalization. Concerning individuals with normal SE, we hypothesize two trajectories. First, based on SE inhibition/desensitization, individuals can temporarily join youths who lack empathy. Second, based on an SE dissociation, combining emotional sympathy increases for the in-group and cognitive empathy decreases toward the out-group.

CONCLUSIONS

While confirming that a lack of empathy can favor radicalization, the counterintuitive hypothesis of a favorable SE development trajectory also needs to be considered to better specify the cognitive and affective aspects of this complex phenomenon.

Similarities and differences in the induction and regulation of the negative emotions fear and disgust: A functional near infrared spectroscopy study

Affective processing, including induction and regulation of emotion, activates neural networks, induces physiological responses, and generates subjective experience. Dysregulation of these processes can lead to maladaptive behavior and even psychiatric morbidity. Multimodal studies of emotion thus not only help elucidate the nature of emotion, but also contribute to important clinical insights. In the present study, we compared the induction (EI) and effortful regulation (ER) with reappraisal of fear and disgust in healthy subjects using functional near infrared spectroscopy (fNIRS) in conjunction with electrodermal activity (EDA). During EI, there was significant activation in medial prefrontal cortex (PFC) for fear and more widespread activation for disgust, with right lateral PFC significantly more active during disgust compared to fear. ER was equally effective for fear and disgust reducing subjective emotion rating by roughly 45%. Compared to baseline, there was no increased PFC activity for fear during ER, while for disgust lateral PFC was significantly more active. Significant differences between the two negative emotions were also observed in sympathetic nerve activity as reflected in EDA during EI, but not during ER. Lastly, compared to men, women had higher emotion rating for both fear and disgust without corresponding differences in EDA. In conclusion, in the present study we show that emotion induction was associated with differential activation in both PFC and sympathetic nerve activity for fear and disgust. These differences were however less prominent during emotion regulation. We discuss the potential interpretation of our results and their implications regarding our understanding of negative emotion processing.

Social cognition and empathy in adults with obsessive compulsive disorder: A meta-analysis

Obsessive-compulsive disorder (OCD) is characterized by intrusive thoughts (obsessions) and compulsions and has been associated with psychosocial impairment. Indeed, a number of studies have highlighted impairments in both social cognitive functions and empathic skills in OCD, despite several inconsistencies. This study aimed to investigate social cognitive dysfunction and empathy deficits in patients with OCD using a meta-analytic approach. A literature search was conducted using the databases Pubmed, PsycINFO, ProQuest and Scopus to identify the relevant studies (January 1980 to March 2020). Following the systematic review of relevant OCD studies, a random-effects meta-analysis was conducted. The current meta-analysis included 25 studies consisting of 1161 patients with OCD and 1329 healthy controls. OCD was associated with decreased performance in theory of mind (ToM). In the facial emotion recognition domain, patients with OCD significantly underperformed healthy controls only in their recognition of disgust. OCD was significantly related to reduced cognitive empathy. OCD was associated with medium-sized impairments in ToM and cognitive empathy, which can likely contribute to psychosocial impairment in this disorder. Further studies are needed to investigate state and trait-related factors using experimental measures of empathy.

Granisetron-mediated augmentation of sertraline therapeutic effect in obsessive-compulsive disorder: a double-blind placebo-controlled, randomized clinical trial

BACKGROUND

Medications currently recommended for the treatment of Obsessive-Compulsive Disorder (OCD) usually relieve the severity of symptoms by as much as 20-30%, and satisfactory treatment is obtained in 40-60% of patients with OCD. Nevertheless, the remaining symptoms continue to impair the patients' function. Therefore, it is necessary to investigate possible strategies to improve the mitigation of symptoms. In this study, the main objective was to examine and investigate the effectiveness of granisetron, which is a serotonin 5-hydroxytryptamine receptor type 3 (5-HT₃) antagonist, as an adjunct therapy to selective serotonin reuptake inhibitors, for the purpose of ameliorating OCD symptoms.

METHODS

fifty-eight patients diagnosed with OCD, based on Diagnostic and Statistical Manual of Mental Disorders (DSM-5) criteria, who had a Yale-Brown obsessive-compulsive scale (Y-BOCS) score of more than 21 were recruited in a double-blinded, parallel-group, placebo-controlled, clinical trial of 10 weeks to receive either granisetron (1 mg twice daily) and sertraline (100 mg daily initially followed by 200 mg daily after week 4) or placebo and sertraline. The primary outcome was OCD symptoms measured by the Y-BOCS.

RESULTS

Y-BOCS total score significantly dropped in both groups (28.9 to 17.7 for granisetron plus sertraline and 27.5 to 19.3 for placebo plus sertraline group with a slightly greater drop for granisetron plus sertraline group), while the granisetron plus sertraline group experienced a significantly greater reduction in obsession scores (Greenhouse-Geisser F(2.32,97.57) = 4.52,p-value = 0.01). Moreover, in comparison with the placebo plus sertraline group, the proportion of the patients showing complete response was considerably higher among the granisetron plus sertraline group (P-value < 0.01). No major adverse effects were observed in any of the groups.

CONCLUSION

The results suggest that granisetron augmentation of sertraline may increase the rate of response in patients with moderate to severe non-refractory OCD. Further studies are suggested in this regard.

Functional Connectivity within the Frontal–Striatal Network Differentiates Checkers from Washers of Obsessive-Compulsive Disorder

Background: Obsessive-compulsive disorder (OCD) is a psychiatric disorder with high clinical heterogeneity manifested by the presence of obsessions and/or compulsions. The classification of the symptom dimensional subtypes is helpful for further exploration of the pathophysiological mechanisms underlying the clinical heterogeneity of OCD. Washing and checking symptoms are the two major symptom subtypes in OCD, but the neural mechanisms of the different types of symptoms are not yet clearly understood. The purpose of this study was to compare regional and network functional alterations between washing and checking OCD based on resting-state functional magnetic resonance imaging (rs-fMRI). Methods: In total, 90 subjects were included, including 15 patients in the washing group, 30 patients in the checking group, and 45 healthy controls (HCs). Regional homogeneity (ReHo) was used to compare the differences in regional spontaneous neural activity among the three groups, and local indicators were analyzed by receiver operating characteristic (ROC) curves as imaging markers for the prediction of the clinical subtypes of OCD. Furthermore, differently activated local brain areas, as regions of interest (ROIs), were used to explore differences in altered brain functioning between washing and checking OCD symptoms based on a functional connectivity (FC) analysis. Results: Extensive abnormalities in spontaneous brain activity involving frontal, temporal, and occipital regions were observed in the patients compared to the HCs. The differences in local brain functioning between checking and washing OCD were mainly concentrated in the bilateral middle frontal gyrus, right supramarginal gyrus, right angular gyrus, and right inferior occipital gyrus. The ROC curve analysis revealed that the hyperactivation right middle frontal gyrus had a better discriminatory value for checking and washing OCD. Furthermore, the seed-based FC analysis revealed higher FC between the left medial superior frontal gyrus and right caudate nucleus compared to that in the healthy controls. Conclusions: These findings suggest that extensive local differences exist in intrinsic spontaneous activity among the checking group, washing group, and HCs. The neural basis of checking OCD may be related to dysfunction in the frontal–striatal network, which distinguishes OCD from washing OCD.

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.

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.

An implicit priming intervention alters brain and behavioral responses to high-calorie foods: a randomized controlled study

BACKGROUND

Conditioned food cues (e.g., smell, sight) can affect intake of foods associated with those cues, regardless of homeostatic need. As such, altering automatic associations with food cues could support weight loss or maintenance efforts by affecting the salience of those cues and the effort required to resist consumption.

OBJECTIVES

This study investigated neuronal and behavioral effects of an implicit priming (IP) intervention, in which negatively valenced images were paired with high-calorie foods and positively valenced images with low-calorie foods. Priming images were presented immediately before food images, but below conscious perception (20 ms). We hypothesized that this evaluative conditioning approach could alter food cue responses by modifying affective associations.

METHODS

The final sample included 41 adults with BMI ≥25 kg/m2 (n = 22, active IP; n = 19, control IP). In control IP, food images were primed with neutral, scrambled images. Participants completed a visual food cue task during fMRI, both before and after IP. To determine the replicability of prior behavioral findings, food image ratings were completed before and after IP as a secondary outcome.

RESULTS

In a whole-brain analysis, reduced dorsolateral prefrontal cortex (dlPFC) response to high-calorie foods was observed after active compared with control IP (t = 4.93, P = 0.033). With a region of interest analysis, reduced response to high-calorie foods in active compared with control IP was also observed in the striatum (t = 2.40, P = 0.009) and insula (t = 2.38, P = 0.010). Active compared with control IP was associated with reduced high-calorie food ratings (F = 4.70, P = 0.038).

CONCLUSIONS

Reduced insula and striatum response to high-calorie foods after active compared with control IP suggests effectiveness of IP in altering food cue salience. Reduced dlPFC response to high-calorie foods after active compared with control IP may reflect fewer attentional resources being directed to those images and reduced engagement of inhibitory processes.This trial was registered at clinicaltrials.gov as NCT02347527.

Design and Validation of Augmented Reality Stimuli for the Treatment of Cleaning Obsessive-Compulsive Disorder

Fear to contamination is an easy-to-provoke, intense, hard-to-control, and extraordinarily persistent fear. A worsening of preexisting psychiatric disorders was observed during the COVID-19 (coronavirus disease 2019) outbreak, and several studies suggest that those with obsessive-compulsive disorder (OCD) may be more affected than any other group of people. In the face of worsening OCD symptoms, there is a need for mental health professionals to provide the support needed not only to treat patients who still report symptoms, but also to improve relapse prevention. In this line, it is recommended to improve alternative strategies such as online consultations and digital psychiatry. The aim of this study is to develop augmented reality (AR) stimuli that are clinically relevant for patients with cleaning OCD and assess their efficiency to obtain emotionally significant responses. Four AR stimuli were developed: a plastic bag full of garbage, a piece of bread with mold, a dirty sports shoe, and a piece of rotten meat. All stimuli were shown to a clinical group (17 patients with cleaning OCD) and a control group (11 patients without OCD). Relevant results were the design of the AR stimuli. These stimuli were validated with the statistical difference in perceived anxiety in the meat stimuli between the clinical and control groups. Nevertheless, when looking at effect sizes, all stimuli present effect sizes from small (plastic bag) to large (meat), with both shoe and bread between small and medium effect sizes. These results are a valuable support for the clinical use of these AR stimuli in the treatment of cleaning OCD.

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 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.

Subjective Experience of Disgust

Abstract. Background: Individual differences in the experience of disgust are known to influence the development and maintenance of several psychopathologies. Aims: This study examined the psychometric properties of the Portuguese version of the Disgust Propensity and Sensitivity Scale – Revised (DPSS-R). Method: The factor validity, the reliability of the Portuguese version of DPSS-R, the convergent validity, and the relationship with other scales were assessed in 229 participants. Results: The modified two-factor model, disgust propensity and sensitivity, was confirmed with good fit indexes and with acceptable convergent and discriminant validity. Overall, the internal consistency and the composite reliability of the DPSS-R were appropriate. The DPSS-R also revealed significant associations with the Disgust Scale, Maudsley Obsessive-Compulsive Inventory, Spider Phobia Questionnaire – Revised, and State-Trait Anxiety Inventory. Specifically, the disgust propensity factor was found to be a significant predictor of fear of spiders and trait anxiety, whereas both DPSS-R factors predicted obsessive-compulsive symptoms. Finally, women reported higher levels of disgust propensity and sensitivity than men. Conclusion: The Portuguese version of the DPSS-R proved to be a valid and reliable measure of disgust propensity and sensitivity and, therefore, with potential relevance for application in both research and clinical practice.

Disgust propensity and sensitivity in childhood anxiety and obsessive-compulsive disorder: Two constructs differentially related to obsessional content

The role of disgust in anxiety and related disorders has been extensively studied in adults, however its role in childhood psychopathology is in need of further investigation. The adult literature has suggested that two distinct sub-constructs within "disgust proneness" may differentially predict anxiety-related disorders. Namely, disgust propensity (DP) has been defined as the likelihood an individual will experience a disgust reaction, and disgust sensitivity (DS) as the degree to which an individual is distressed by their experience of disgust. The current study aimed to validate the Disgust Propensity and Sensitivity Scale-Revised (DPSS-R) in a sample of youth receiving intensive services for OCD and anxiety, examine the relationship between disgust sub-constructs and obsessional content in a sample of youth with OCD, and examine the relationship between disgust change and symptom severity at discharge. A confirmatory factor analysis supported a two-factor structure of the DPSS-R. DP was found to be uniquely predictive of contamination obsessions, and DS was found to be uniquely predictive of moral obsessions. Lastly, change in DP, but not DS, predicted overall change in OCD symptom severity. The present study provides a valid measure of DS and DP in youth with anxiety and related disorders, and suggests that subconstructs of disgust may serve as distinct risk factors for obsessional content in youth with OCD. Future research should examine the predictive validity of DP and DS longitudinally, as well as examine effective ways to more effectively target DP with exposure therapy.

Examining the functional activity of different obsessive-compulsive symptom dimensions in Tourette syndrome

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Patients with Tourette Syndrome completed an obsessive–compulsive provocation task.

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Patients reported higher anxiety for the provocation conditions than did controls.

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Group differences found in the insula, sensorimotor cortex and supramarginal gyri.

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Obsessive–compulsive severity associated with frontal and parietal lobe activity.

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Tic severity associated with anterior cingulate activity for the symmetry condition.

Objectives

Tourette syndrome (TS) is commonly comorbid with obsessive–compulsive disorder (OCD) and many phenomenological similarities exist between tics and obsessive–compulsive symptoms (OCS). Therefore, due to the clinical importance of comorbid OCD, the goal of this study was to investigate the neural substrates of OCS in TS using functional magnetic resonance imaging.

Methods

Forty patients with TS and 20 healthy controls underwent functional magnetic resonance imaging while viewing blocks of OCS-provoking pictures relating to washing, checking and symmetry symptoms, as well as generally disgusting and neutral scenes. Statistical comparisons were made between patients with moderate/severe OCS, absent/mild OCS and healthy controls. As well, within the entire TS patient group, significant associations with clinical measures were assessed for each of the provocation conditions.

Results

Group differences in the insula, sensorimotor cortex, supramarginal gyrus and visual processing regions were common among the checking, washing and disgust conditions. In the patient group, negative associations between OCS severity and activity in the supramarginal gyrus, inferior frontal gyrus, sensorimotor cortex, precuneus and visual processing regions were common among the provocation conditions. Tic severity was only associated with activity in the anterior cingulate cortex for the symmetry condition.

Conclusion

Our findings implicate areas previously reported to be involved in OCD, as well as areas not typically implicated in OCD, suggesting that the neurobiological profile of TS+OCD is intermediate to pure TS and pure OCD.

Social Cognition and Obsessive-Compulsive Disorder: A Review of Subdomains of Social Functioning

Disturbances in social cognitive processes such as the ability to infer others' mental states importantly contribute to social and functional impairments in psychiatric disorders. Yet, despite established social, emotional, and cognitive problems, the role of social cognition in obsessive-compulsive disorder is largely overlooked. The current review provides a first comprehensive overview of social (neuro)cognitive disturbances in adult patients with obsessive-compulsive disorder. Results of our review indicate various social cognitive alterations. Patients with obsessive-compulsive disorder show deficits in the recognition of affective social cues, specifically facial expressions of disgust, and more general deficits in theory of mind/mentalizing. Additionally, patients show heightened affective reactions and altered neural responding to emotions of self and others, as well as poor emotion regulation skills, which may contribute to poor social functioning of patients. However, the discrepancies in findings and scarcity of studies make it difficult to draw firm conclusions with regard to the specificity of social cognitive disturbances. The review offers directions for future research and highlights the need to investigate obsessive-compulsive disorder from an interactive social neurocognitive perspective in addition to the prevalent passive spectator perspective to advance our understanding of this intricate and burdensome disorder.

Imagery Rescripting on Guilt-Inducing Memories in OCD: A Single Case Series Study

BACKGROUND AND OBJECTIVES

Criticism is thought to play an important role in obsessive-compulsive disorder (OCD), and obsessive behaviors have been considered as childhood strategies to avoid criticism. Often, patients with OCD report memories characterized by guilt-inducing reproaches. Starting from these assumptions, the aim of this study is to test whether intervening in memories of guilt-inducing reproaches can reduce current OCD symptoms. The emotional valence of painful memories may be modified through imagery rescripting (ImRs), an experiential technique that has shown promising results.

METHODS

After monitoring a baseline of symptoms, 18 OCD patients underwent three sessions of ImRs, followed by monitoring for up to 3 months. Indexes of OCD, depression, anxiety, disgust, and fear of guilt were collected.

RESULTS

Patients reported a significant decrease in OCD symptoms. The mean value on the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) changed from 25.94 to 14.11. At the 3-month follow-up, 14 of the 18 participants (77.7%) achieved an improvement of ≥35% on the Y-BOCS. Thirteen patients reported a reliable improvement, with ten reporting a clinically significant change (reliable change index = 9.94). Four reached the asymptomatic criterion. Clinically significant changes were not detected for depression and anxiety.

CONCLUSIONS

Our findings suggest that after ImRs intervention focusing on patients' early experiences of guilt-inducing reproaches there were clinically significant changes in OCD symptomatology. The data support the role of ImRs in reducing OCD symptoms and the previous cognitive models of OCD, highlighting the role of guilt-related early life experiences in vulnerability to OCD.

The role of disgust propensity and sensitivity on sexual excitations and inhibition in obsessive-compulsive disorder

Sexuality is understudied in Obsessive-Compulsive Disorder (OCD). According to the Dual Control Model, low sexual excitation (SE) and high sexual inhibition (SI) are indicative of a higher probability of experiencing a sexual dysfunction. The present study investigated SE and SI in OCD patients compared with controls. It was hypothesized that OCD patients report lower SE and higher SI than controls. Given their potential role as inhibitors of sexual response, it was hypothesized that in the OCD group higher disgust propensity/sensitivity, contamination/washing symptoms, unacceptable thoughts, and obsessive beliefs predicted lower SE, higher SI due to Threat of Performance Failure, and higher SI due to Threat of Performance Consequences. Seventy-two OCD patients and 72 controls matched on gender/age completed the Disgust Propensity and Sensitivity Scale-Revised, Obsessive Beliefs Questionnaire-46, Obsessive Compulsive Inventory- Revised, and Sexual Inhibition/Sexual Excitation Scales. OCD patients had higher SE, SI due to Threat of Performance Failure, and SI due to Threat of Performance Consequences than controls. In the OCD group, higher disgust sensitivity, SI due to Threat of Performance Consequences, and perfectionism predicted higher SI due to Threat of Performance Failure. Higher SI due to Threat of Performance Failure and contamination/washing symptoms predicted higher SI due to Threat of Performance Consequences. These findings highlight the presence of sexual difficulties in OCD patients, particularly a higher SE and SI. The latter is especially relevant in those patients with higher disgust sensitivity, contamination/washing symptoms and perfectionism. Psychotherapists should assess and target sexuality during clinicalpractice with OCD patients.

Neural correlates of symptom provocation in pediatric obsessive-compulsive disorder

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Largest controlled pediatric OCD symptom provocation study.

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Novel standardized symptom provocation picture set for pediatric OCD.

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Behavioral group differences strongest for ‘Just Right’ factor.

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Temporal pole recruited by OCD group.

Obsessive-compulsive disorder

(OCD)-affected adults and children exhibit three to four symptom dimensions with distinct but overlapping neural correlates. No symptom provocation behavioural or imaging study has examined all symptom dimensions in a pediatric OCD sample.

Method

Clinically diagnosed pediatric OCD-affected participants (n = 25) as well as age, gender and Tanner pubertal stage-matched healthy controls (HCs; n = 24) (total sample: mean age = 14.77 ± 2.93 years; age range = 9–18 years; 35% male) viewed alternating blocks of OCD symptom provocation (Contamination, Bad Thoughts, and Just Right symptom dimensions), Fear, Neutral and Rest (i.e. fixation) conditions during functional magnetic resonance imaging. A region-of-interest analysis used seeds based upon results of an adult OCD meta-analysis

Results

OCD participants found OCD symptom-related stimuli bothersome, particularly when compared to controls in the “Just Right” symptom dimension. Pediatric OCD patients exhibited greater recruitment of the left superior temporal gyrus (STG) than healthy controls during combined symptom provocation versus neutral conditions.

Conclusion

Findings suggest involvement of the temporal poles rather than in classic cortico-striatal-thalamico-cortical circuits in pediatric OCD during symptom provocation.