Attention bias in adults with anorexia nervosa, obsessive-compulsive disorder, and social anxiety disorder

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.

Genetic polymorphisms in the serotonin, dopamine and opioid pathways influence social attention in rhesus macaques (Macaca mulatta)

Behaviour has a significant heritable component; however, unpicking the variants of interest in the neural circuits and molecular pathways that underpin these has proven difficult. Here, we present a comprehensive analysis of the relationship between known and new candidate genes from identified pathways and key behaviours for survival in 109 adult rhesus macaques (Macaca mulatta). Eight genes involved in emotion were analysed for variation at a total of nine loci. Genetic data were then correlated with cognitive and observational measures of behaviour associated with wellbeing and survival using MCMC-based Bayesian GLMM in R, to account for relatedness within the macaque population. For four loci the variants genotyped were length polymorphisms (SLC6A4 5-hydroxytryptamine transporter length-polymorphic repeat (5-HTTLPR), SLC6A4 STin polymorphism, Tryptophan 5-hydroxylase 2 (TPH2) and Monoamine oxidase A (MAOA)) whilst for the other five (5-hydroxytryptamine receptor 2A (HTR2A), Dopamine Receptor D4 (DRD4), Oxytocin receptor (OXTR), Arginine vasopressin receptor 1A (AVPR1a), Opioid receptor mu(μ) 1 (OPRM1)) SNPs were analysed. STin genotype, DRD4 haplotype and OXTR haplotype were significantly associated with the cognitive and observational measures of behaviour associated with wellbeing and survival. Genotype for 5-HTTLPR, STin and AVPR1a, and haplotype for HTR2A, DRD4 and OXTR were significantly associated with the duration of behaviours including fear and anxiety. Understanding the biological underpinnings of individual variation in negative emotion (e.g., fear and anxiety), together with their impact on social behaviour (e.g., social attention including vigilance for threat) has application for managing primate populations in the wild and captivity, as well as potential translational application for understanding of the genetic basis of emotions in humans.

Attention Biases for Eating Disorder-Related Stimuli Versus Social Stimuli in Adolescents with Anorexia Nervosa - An Eye-Tracking Study

Anorexia nervosa (AN) is characterized by attention biases for eating disorder-related information as well as altered attentional processing of social information. However, little is known about the interplay between the altered attentional processing of these two types of information. The present study investigates attention biases for eating disorder-related information (pictures of bodies) versus social information (pictures of faces), in adolescents with AN. Attention biases were assessed via eye-tracking during a passive-viewing task in which female bodies and faces were presented simultaneously and thus competed directly for attention. Female adolescents (13-18 years) with AN (n = 28) were compared to a clinical comparison group (adolescents with major depression; n = 20) and a comparison group of adolescents with no mental illness (n = 24). All groups looked longer at bodies than at faces, i.e., showed attention biases for bodies in maintenance of attention. These biases were more pronounced in adolescents with AN than in both comparison groups, particularly for underweight bodies, at the expense of looking less at social stimuli. The results indicate "dual" attention biases in adolescents with AN (i.e., towards bodies and away from emotional faces) which could have a twofold negative impact on eating disorder psychopathology: increased attention to eating disorder-related information might directly influence eating disorder symptoms while less attention to social information might have an indirect influence through the amplification of interpersonal difficulties.

Attentional bias variability and its association with psychological and health symptoms: A meta-analysis

The present meta-analysis sought to assess the association between an emerging neurocognitive marker of psychopathology in attentional bias variability (ABV) and key psychological and health outcomes. A comprehensive literature review yielded 53 studies in 43 manuscripts (N = 5428). Overall, clinical and sub-clinical samples exhibited greater ABV than control samples (g = 0.462). Trauma samples showed significantly greater ABV than control samples (g = 0.782, medium-large effect), whereas social anxiety samples did not (g = 0.147). Similarly, ABV was associated with degree of trauma symptoms (r = 0.21 - 0.25). ABV was associated with some symptoms of depression and anxiety, although these were small and inconsistent. These findings suggest a specific relationship between ABV and post-traumatic stress symptoms, with evidence equivocal for other psychological difficulties (although also less research). Key recommendations for future research include investigating mechanisms underlying ABV and the importance of controlling for non-attentional processes, such as reaction time variability, to ensure the validity of ABV measures.

Valence processing alterations in SAPAP3 knockout mice and human OCD

Abnormalities in valence processing - the processing of aversive or appetitive stimuli - may be an underrecognized component of obsessive-compulsive disorder (OCD). Preclinical rodent models have been critical in furthering pathophysiological understanding of OCD, yet there is a dearth of investigations examining whether rodent models of compulsive behavior show alterations in valence systems congruent with those seen in individuals with OCD. In this study, we sought to assess valence processing in a preclinical rodent model of compulsive behavior, the SAPAP3 knockout (KO) mouse model, and compare our preclinical findings to similar behavioral phenomena in OCD patients. In SAPAP3 KO mice, we used auditory fear conditioning and extinction to examine alterations in negative valence processing and reward-based operant conditioning to examine alterations in positive valence processing. We find that SAPAP3 KO mice show evidence of heightened negative valence processing through enhanced fear learning and impaired fear extinction. SAPAP3 KO mice also show deficits in reward acquisition and goal-directed behavior, suggesting impaired positive valence processing. In OCD patients, we used validated behavioral tests to assess explicit and implicit processing of fear-related facial expressions (negative valence) and socially-rewarding happy expressions (positive valence). We find similar trends towards enhanced negative and impaired positive valence processing in OCD patients. Overall, our results reveal valence processing abnormalities in a preclinical rodent model of compulsive behavior similar to those seen in OCD patients, with implications for valence processing alterations as novel therapeutic targets across a translational research spectrum.

A multifaceted study of interpersonal functioning and cognitive biases towards social stimuli in adolescents with eating disorders and healthy controls

BACKGROUND

Cognitive biases towards social stimuli have been identified as one of the putative modifiable mechanisms to remediate interpersonal difficulties in adolescents with mental disorders. However, evidence for these biases in adolescents with eating disorders is scarce.

METHODS

This study assessed interpersonal sensitivity, cognitive biases towards social stimuli, and quantity and quality of social group memberships in adolescents with eating disorders (n = 80), compared to healthy controls (n = 78), and examined whether a negative interpretation bias would mediate the relationship between interpersonal sensitivity, eating disorder symptoms and positive group memberships.

RESULTS

Adolescents with eating disorders displayed greater interpersonal awareness, negative interpretation biases of ambiguous social information and poorer quality relationships with their social groups compared to healthy controls. In a simple mediation model, interpersonal awareness predicted eating disorder symptoms, and this effect was partially mediated by a negative interpretation bias.

CONCLUSIONS

Psychological interventions which aim to reduce a negative interpretation bias might help to reduce the severity of eating disorder symptoms in adolescents with eating disorders.

The KOALA-study: study protocol for a comprehensive study of cognitive biases in adolescent anorexia nervosa patients compared to healthy and clinical controls

BACKGROUND

Anorexia nervosa (AN) is characterized by dysfunctional cognitions including cognitive biases at various levels of information processing. However, less is known about the specificity of these biases, i.e., if they occur for eating-disorder-related information alone or also for non-eating-disorder-related emotional information in AN patients (content-specificity) and if they are unique to individuals with AN or are also shown by individuals with other mental disorders (disorder-specificity).

METHODS

The present study systematically assesses cognitive biases in 12-18-year-old female adolescents with AN on three levels of information processing (attention, interpretation, and memory) and with regard to two types of information content (eating-disorder-related, i.e., stimuli related to body weight and shape, and non-eating-disorder-related). To address not only content- but also disorder-specificity, adolescents with AN will be compared not only to a healthy control group but also to a clinical control group (adolescents with major depression or particular anxiety disorders). Cognitive biases are assessed within a single experimental paradigm based on the Scrambled Sentences Task. During the task eye movements are recorded in order to assess attention biases while interpretation biases are derived from the behavioural outcome. An incidental free recall test afterwards assesses memory biases. We expect adolescents with AN to show more pronounced negative cognitive biases on all three levels of information processing and for both types of content compared to healthy adolescents. In addition, we expect the specificity of biases to translate into differential results for the two types of content: AN patients are expected to show stronger biases for disorder-related stimuli but similar or less pronounced biases for non-disorder-related stimuli compared to the clinical control group.

DISCUSSION

This is the first study to comprehensively assess cognitive biases in adolescents with AN. It will have essential implications not only for cognitive-behavioural models of AN but also for subsequent studies aiming to modify cognitive biases in this population, thereby addressing important maintaining factors already at an early stage of the disorder.

The use of trial-level bias scores to examine attention bias and attention bias variability among people with and without social anxiety disorder

BACKGROUND

Cognitive models of anxiety propose that people with anxiety disorders show elevated levels of attention bias toward threat, but the most commonly used index of attention bias, which measures the construct with an aggregate score of multiple trials across an experimental session, shows poor test-retest reliability. Newer indices that measure attention bias dynamically on a trial-to-trial basis show good reliability and enable researchers to measure not only overall attention bias toward threat, but also attention bias variability.

METHODS

The current study tested the hypothesis that people diagnosed with social anxiety disorder would show higher attention bias variability and higher attention bias toward threat when calculated dynamically and when calculated using the traditional aggregate index. Participants diagnosed with social anxiety disorder (n = 47) and controls (n = 57) completed a 160-trial version of the dot-probe task using emotional and neutral images of faces as stimuli.

RESULTS

Relative to controls, participants diagnosed with social anxiety disorder showed higher mean bias toward threat, but only when calculated using trial-level bias scores. There were no differences between groups on attention bias variability.

DISCUSSION

This is the first study to examine differences in attention bias and attention bias variability between people with and without social anxiety disorder using trial-level bias scores. Results suggest that attention bias, but not attention bias variability, is a feature of social anxiety psychopathology and that trial-level bias scores may be more sensitive than aggregated mean scores to detect it. These findings have implications for clinical interventions such as attention bias modification programs, which require precise measures of attention bias to accurately assess treatment outcomes.

Comorbid obsessive-compulsive disorder in individuals with eating disorders: An epidemiological meta-analysis

The present study aimed to provide a precise, meta-analytic estimate of the prevalence of obsessive-compulsive disorder (OCD) amongst those with a current primary eating disorder (ED) diagnosis, and to isolate its predictors. An online search of PubMed and PsycINFO was conducted with a Boolean search phrase incorporating keywords related to OCD, EDs, comorbidity, prevalence, and epidemiology, complemented by references coded from related review articles and contact with experts in the field. Articles were included if they (a) reported an observational study examining current ED diagnoses, (b) used a semi-structured or structured diagnostic interview for OCD and ED diagnosis, (c) applied DSM or ICD criteria, (d) included adolescent or adult samples (age > 12), (e) included patient or community samples, and (f) reported lifetime or current OCD comorbidity. From the 846 articles identified, 35 lifetime and 42 current estimates were calculated. OCD prevalence was extracted from each study for each ED diagnostic category, along with eleven additional potential moderators. Analyses revealed an aggregate lifetime OCD prevalence of 13.9% CI_95% [10.4 to 18.1] and current OCD prevalence of 8.7% CI_95% [5.8 to 11.8] across EDs. Moderator analyses revealed the prevalence of and risk for OCD in EDs to be greatest in anorexia nervosa binge-eating purging type (ANBP). Further, OCD is most prevalent amongst patient samples than samples recruited from the community.

Dissection of the Genetic Association between Anorexia Nervosa and Obsessive-Compulsive Disorder at the Network and Cellular Levels

Anorexia nervosa (AN) and obsessive-compulsive disorder (OCD) exhibit a high co-morbidity rate, similar symptoms, and a shared genetic basis. However, an understanding of the specific underlying mechanisms of these commonalities is currently limited. Here, we collected Genome-Wide Association Analysis results for AN and OCD, and obtained genes hit by the top SNPs as the risk genes. We then carried out an integrative coexpression network analysis to explore the convergence and divergence of AN and OCD risk genes. At first, we observed that the AN risk genes were enriched in coexpression modules that involved extracellular matrix functions and highly are expressed in the postnatal brain, limbic system, and non-neuronal cell types, while the OCD risk genes were enriched in modules of synapse function, the prenatal brain, cortex layers, and neurons. Next, by comparing the expressions from the eating disorder and OCD postmortem patient brain tissues, we observed both disorders have similar prefrontal cortex expression alterations influencing the synapse transmission, suggesting that the two diseases could have similar functional pathways. We found that the AN and OCD risk genes had distinct functional and spatiotemporal enrichment patterns but carried similar expression alterations as a disease mechanism, which may be one of the key reasons they had similar but not identical clinical phenotypes.

Rates of comorbid obsessive-compulsive disorder in eating disorders: A meta-analysis of the literature

BACKGROUND

The high comorbidity between Eating Disorders (EDs) and Obsessive-Compulsive disorder (OCD) is well known, as well as its implications in terms of worse outcome and need to adapt treatment. Estimates of OCD comorbidities in EDs are variable in different studies and poorly informative for clinical purposes. In this study, we sought to derive more consistent estimates, taking into account potential methodological and sampling confounding factors.

METHODS

We searched published studies reporting lifetime and current rates of comorbid OCD in ED samples based on recent diagnostic criteria. Comorbidity rates were meta-analyzed using a binary random effects model. Heterogeneity among the studies and publication bias were systematically checked. Potential confounding factors were tested by meta-regression analysis and adjusted by sensitivity analysis.

RESULTS

Globally, respectively 18% and 15% of all patients with an ED had a lifetime and current comorbidity with OCD. Rates were slightly higher in anorexia (19% and 14%) than in bulimia nervosa (13% and 9%), although only the current comorbid OCD was significantly higher in anorexia than in bulimia. Prospective follow-up studies provided considerably higher lifetime estimates (EDs 38%, anorexia 44%, bulimia 19%).

LIMITATIONS

Temporal/causal relationship between ED and OCD could not be defined.

CONCLUSIONS

OCD comorbidity in EDs is a relevant phenomenon, affecting almost one fifth of the patients in cross-sectional observations and up to nearly 40% in prospective follow-up studies. These data indicate the need for focused attention to non-food or body-shape related OCD symptoms, for better diagnostic and prognostic accuracy, and targeted treatment.

A systematic review of studies probing longitudinal associations between anxiety and anorexia nervosa

The current study aimed to establish whether anxiety predicts subsequent anorexia nervosa onset and maintenance. A systematic review of longitudinal studies assessing the association between stable anxiety exposures (e.g. trait anxiety/anxiety disorder pathology) and anorexia nervosa development or maintenance was undertaken. Eight studies met inclusion criteria. Seven probed the association between anxiety and anorexia nervosa onset, and one assessed the association between anxiety and anorexia nervosa maintenance. Individuals with anorexia nervosa were more likely to report childhood anxiety compared to healthy individuals, but whether childhood anxiety explains unique variance in anorexia nervosa development is unclear. Current evidence does not support longitudinal associations between specific anxiety disorders (independently of other anxiety disorders) and subsequent anorexia nervosa onset, however anxiety disorder diagnosis in general may predict increased anorexia nervosa risk. The single study probing the association between anxiety and anorexia nervosa maintenance did not find evidence supporting a relationship. The quality of individual studies was fair to high, however the body of evidence was of low quality. Further research that minimises bias, allowing for strong conclusions concerning longitudinal associations between anxiety and subsequent anorexia nervosa outcomes, is required to inform anorexia nervosa aetiology. This in turn may promote improved prevention and treatment.

Cognitive Neuroscience of Eating Disorders

Anorexia nervosa and bulimia nervosa are characterized by severely restricted intake, binge eating, and compensatory behaviors like self-induced vomiting. The neurobiological underpinnings of these maladaptive behaviors are poorly understood, but the application of cognitive neuroscience and neuroimaging to eating disorders has begun to elucidate their pathophysiology. Specifically, this review focuses on 3 areas that suggest paths forward: reward, cognitive and behavioral control, and decision making. Understanding the brain-based mechanisms that promote and maintain these often chronic symptoms could guide the development of new and more effective treatments.

Social anxiety in the eating disorders: a systematic review and meta-analysis

Social anxiety disorder is one of the most common comorbid conditions in eating disorders (EDs). The aim of the current review and meta-analysis is to provide a qualitative summary of what is known about social anxiety (SA) in EDs, as well as to compare levels of SA in those with EDs and healthy controls. Electronic databases were systematically searched for studies using self-report measures of SA in ED populations. In total, 38 studies were identified, 12 of which were included in the meta-analyses. For both anorexia nervosa (AN) and bulimia nervosa, there were significant differences between ED groups and HCs, with medium to large effect sizes. Findings from the qualitative review indicate that levels of SA are similar across the ED diagnoses, and SA improves with treatment in AN. In addition, high levels of SA are associated with more severe ED psychopathology, but not body mass index. These findings add to the wider literature on socio-emotional functioning in EDs, and may have implications for treatment strategies.