Set shifting and visuospatial organization deficits in body dysmorphic disorder

A systematic review of neurocognition and social cognition in body dysmorphic disorder

OBJECTIVE

Neurocognitive underpinnings are implicated in the aetiology and maintenance of body dysmorphic disorder (BDD); however, inconsistent findings across a range of neurocognitive domains suggest that a comprehensive synthesis of the literature using a hierarchical framework of neurocognition is needed.

METHODS

A final search across OVID Medline, PsycNET, Scopus and Web of Science databases was conducted on 20 June 2024 to identify research that examined performance on behavioural tasks of objective neurocognition in BDD. Risk of bias was assessed using the Newcastle-Ottawa Scale. Fifty-four studies aligned with the following inclusion criteria: (1) full-text; (2) peer-reviewed; (3) published in English; (4) employed a neurocognitive task with an objective outcome and (5) involved a case-controlled paradigm consisting of BDD and healthy control samples. Findings were synthesised according to neurocognitive sub-domains viewed as a hierarchy from basic to higher-level domains.

RESULTS

Neurocognitive differences in BDD relative to controls were identified at almost all levels of the hierarchy, most consistently in the upper domains of executive function and social cognition. Vulnerabilities were also demonstrated in the sub-domains of visual perception of faces, Gestalt processing, selective attention to faces and verbal memory. Methodological limitations or the influence of neurocognitive sub-groups may contribute to inconsistencies across the literature.

CONCLUSIONS

Although neurocognitive differences appear central to BDD, a picture of neurocognitive heterogeneity emerged with the salience of stimuli important and a likely bias to local-over-global processing demonstrated across the domains.

Body dysmorphic disorder

Body dysmorphic disorder (BDD) is an obsessive-compulsive disorder-related psychiatric condition characterized by an intense preoccupation with perceived physical flaws that are not observable by others. BDD affects ~2% of the adult population but is underdiagnosed, partly owing to limited clinician awareness, and undertreated, partly due to limited access to treatment. Research on the aetiology of BDD is scarce but likely involves an interplay between genetic and environmental factors. A few studies suggest functional and structural brain differences (compared with controls) in the regions involved in visual and emotional processing, although firm conclusions about the pathophysiology of the disorder cannot be made at this stage. Diagnosis requires the presence of repetitive behaviours or mental acts typically aimed at checking, correcting or concealing perceived flaws. The disorder typically has its onset before 18 years of age, with a female preponderance in youth but no major gender disparity in adults. Quality of life is markedly impaired across multiple domains and suicide risk is considerable. Evidence-based treatments include cognitive behavioural therapy and selective serotonin reuptake inhibitors. Future research should focus on understanding the biological and environmental factors that increase the risk of BDD, and on improving access to effective treatments, thereby addressing a critical gap in care for this often misunderstood and overlooked disorder.

A systematic review of visual processing in body dysmorphic disorder (BDD)

To understand the visual preponderance of perceived flaws in appearance in body dysmorphic disorder (BDD), the study of visual processing has been growing. Studies have focused on facial and other basic visual stimuli. The current literature does not provide evidence of consistent behavioural patterns, lacking an overarching body of work describing visual processing in BDD. This systematic review aims to characterise behavioural outcomes of visual processing anomalies and/or deficits in BDD. Articles were collected through online databases MEDLINE and PubMed, and were included if they comprised a clinical BDD group, and were published after 1990. Results indicate that individuals with BDD demonstrate deficits in emotional face processing, a possible overreliance on detail processing, aberrant eye-scanning behaviours, and a tendency to overvalue attractiveness. While findings consistently signal towards visual deficits in BDD, there is lack of clarity as to the type. This inconsistency may be attributed to heterogeneity within BDD samples and differences in experimental design (i.e., stimuli, tasks, conditions). There are difficulties distinguishing between BDD-associated deficits and those associated with OCD or eating disorders. A coherent framework, including sample characterisation and task design will seek to generate clear and consistent behavioural patterns to guide future treatments.

Visual Perceptual Processing Abnormalities in Body Dysmorphic Disorder

Phenomenological observations of individuals with body dysmorphic disorder (BDD), coupled with evidence from neuropsychological, psychophysical, and neuroimaging studies, support a model of aberrant visual perception characterized by deficient global/holistic, enhanced detail/local processing, and selective visual-attentional biases. These features may contribute to the core symptomatology of distorted perception of their appearance, in addition to misinterpretation of others' facial expressions and poor insight regarding their misperceived appearance defects. Insights from visual processing studies can contribute to the development of novel interventions, such as perceptual retraining and non-invasive neuromodulation. However, much remains to be understood about visual perception in BDD. Future research should leverage brain imaging modalities with high temporal resolutions and employ study designs that induce conflicts in multisensory integration, thereby advancing our mechanistic understanding of distorted visual perception observed in BDD.

Mechanisms of cognitive behavioral therapy vs. supportive psychotherapy in body dysmorphic disorder: An exploratory mediation analysis

Body dysmorphic disorder (BDD) is common, severe, and often chronic. Cognitive behavioral therapy (CBT) is the first-line psychosocial treatment for BDD, with well-established efficacy. However, some patients do not improve with CBT, and little is known about how CBT confers its effects. Neurocognitive processes have been implicated in the etiology and maintenance of BDD and are targeted by CBT-BDD treatment components. Yet, the malleability of these factors in BDD, and their potential role in mediating symptom improvement, are not well understood. Understanding how treatment works could help optimize treatment outcomes. In this secondary data analysis of a randomized clinical trial of CBT vs. supportive psychotherapy (SPT) in BDD (n = 120), we examined whether treatment-related changes in detail processing (Rey-Osterrieth Complex Figure test), maladaptive appearance beliefs (Appearance Schemas Inventory-Revised), and emotion recognition (Emotion Recognition Task) mediated treatment outcome. All constructs improved over time and were associated with symptom improvement. CBT was associated with greater improvements in maladaptive beliefs than SPT. None of the variables examined mediated symptom improvement. Findings suggest that with successful treatment, individuals with BDD demonstrate reduced neurocognitive deficits (detail processing, emotion recognition, maladaptive beliefs) and that CBT is more likely than SPT to improve maladaptive appearance beliefs. More work is needed to understand mechanisms of change and thus maximize treatment outcomes.

Executive functioning in body dysmorphic disorder and obsessive-compulsive disorder

OBJECTIVE

To assess executive functions (EFs) in patients with body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD) compared with healthy controls.

METHODS

Adults diagnosed with BDD (n = 26) or OCD (n = 29) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and healthy controls (n = 28) underwent validated and computerized neuropsychological tests, spatial working memory (SWM), intra-extra-dimensional set shifting (IED), and stop signal task (SST), from the Cambridge Neuropsychological Test Automated Battery (CANTAB). Test performance was compared between groups, and correlated with standardized symptom severity of BDD and OCD. Significance level was set to P < .05.

RESULTS

There were no statistically significant between-group differences on key outcome measures in SWM, IED, or SST. There was a weak positive correlation between symptom severity and test errors on SWM and IED in both OCD and BDD groups; increased clinical severity was associated with more errors in these tests. Furthermore, there was a negative correlation between symptom severity and SST in the BDD group.

CONCLUSIONS

Patients with BDD or OCD did not differ from healthy control subjects in terms of test performance; however, there were several statistically significant correlations between symptom severity and performance in those with BDD or OCD. More studies on EFs in BDD and OCD are required to elucidate if there are differences in EFs between these two disorders.

Epidemiology of body dysmorphic disorder among adolescents: A study of their cognitive functions

BACKGROUND

Body dysmorphic disorder (BDD) is characterized by a preoccupation with an imagined defect in one's appearance. In case of a slight physical anomaly, the person would experience an excessive concern. This disorder causes cognitive dysfunction.

PURPOSE

The aim of this study was to examine epidemiology of body dysmorphic disorder among students at secondary schools of the first and second stage in Shiraz, Iran. It also compares executive functions in students with BDD to healthy students.

METHODS

The Body Dysmorphic Disorder Questionnaire (BDDQ), Stroop Color and Word Test (SCWT),Wisconsin Card Sorting Test (WCST), Tower of London test (ToL), and Trail Making Test (TMT) were measured in participants with BDD (N = 52; M_age  = 16.20; SD = 1.03) and healthy control group (N = 52; M_age  = 15.91; SD = 0.96).

RESULTS

The frequency of BDD was significantly higher in women than men (14.8% vs. 6.8%), and its prevalence was 10.4% in total. There was a significant difference between the two groups of students concerning attentional set-shifting, inhibition of cognitive interference, visual-spatial searching, and sequencing, but not problem-solving tasks.

CONCLUSIONS

Students with BDD have cognitive deficits, which need to be addressed in cognitive rehabilitation.

The obsessive-compulsive spectrum: A network analysis

Several studies have shown that obsessive-compulsive disorder (OCD), eating disorders (ED), autism spectrum disorders (ASD) and body dysmorphic disorder (BDD) share obsessive-compulsive (OC) symptoms and often co-occur, which could be seen as indicative of a common etiological basis. In addition, they also appear to have similarities in executive functioning. The present study investigated disorder-specific symptoms and executive functioning as a possible joint factor in individuals with OCD (n=53), BDD (n=95), ED (n=171) and ASD (n=73), and in healthy controls (n=110). The participants completed online questionnaires measuring OCD, ED, ASD and BDD related symptoms as well as executive functioning. The clinical groups were first compared to the healthy controls. Subsequently, a network analysis was performed only with the OC-groups. This network approach assumes that psychopathological disorders are the result of causal symptom interactions. As expected, the healthy controls reported less severe symptoms compared to the OC patient groups. The network analysis suggested that the executive functioning skill set shifting/attention switching and the ASD symptoms, social and communication skills were the most central nodes in the model. Difficulty with cognitive flexibility and social factors are central in OC-spectrum disorders and may be perpetuating factors and thus a relevant focus of treatment.

Cross-diagnostic cognitive heterogeneity in body dysmorphic disorder and obsessive-compulsive disorder

BACKGROUND AND OBJECTIVES

Previous research has indicated that body dysmorphic disorder (BDD) and obsessive-compulsive disorder (OCD) often demonstrate similar cognitive impairments across multiple domains. However, findings for both disorders have not consistently shown impaired cognition. As such, BDD and OCD might share an overlapping pattern of cognitive heterogeneity, characterised by subgroups with different cognitive profiles.

METHODS

To evaluate this possibility, we compared 26 BDD, 24 OCD, and 26 healthy control participants on a comprehensive eight-domain cognitive battery. Then, cluster analysis was performed on the BDD and OCD participants' combined data to explore for cognitive subgroups.

RESULTS

No significant differences were found between the three groups' cognitive functioning, except for poorer visual learning in OCD relative to healthy controls. Cluster analysis produced two cognitive subgroups within the combined BDD and OCD data, characterised by intact cognition (52%) and broadly impaired cognition (48%). Each subgroup comprised both BDD and OCD participants, in similar proportions. The subgroups did not differ in clinical or demographic features.

LIMITATIONS

Sample sizes were moderate. Future research should investigate clustering patterns both in larger groups and separately in BDD and OCD samples to determine replicability.

CONCLUSIONS

These findings suggest that BDD and OCD may involve similar patterns of cognitive heterogeneity, and further imply that individuals with either disorder can show a wide range of cognitive profiles, thus necessitating a nuanced approach to future cognitive research in BDD and OCD.

Is poor global processing a transdiagnostic feature of Body Dysmorphic Disorder and Anorexia Nervosa? A meta-analysis

Body dysmorphic disorder (BDD) and anorexia nervosa (AN) are characterised by body image disturbance. It has been suggested that poor global integration in visual processing may underlie distorted body image, but empirical studies have yielded mixed results. The current study involved two meta-analyses aimed at examining the extent to which poor global processing is evident in BDD and AN. Studies were identified through a systematic literature search up to October 2020. The BDD search yielded 16 studies and the AN search yielded 18 studies. Random-effect models demonstrated a small pooled effect size for BDD (g = -0.44, 95 % CI -0.70, -0.17, p < 0.001) and a moderate pooled effect size for AN (g = -0.63, 95 % CI -0.77, -0.49, p <  .001), with no evidence of significant publication bias for either. The results provide evidence that poor global processing is a transdiagnostic feature of both BDD and AN, although effects may be more pronounced in AN. Our findings highlight the possibility that interventions aimed at promoting global visual processing could prove beneficial in disorders characterised by distorted body image.

Empirical evidence for cognitive subgroups in body dysmorphic disorder

OBJECTIVE

Current understanding of cognitive functioning in body dysmorphic disorder is limited, owing to few studies, small sample sizes and assessment across only limited cognitive domains. Existing research has also shown inconsistent findings, with both intact and impaired cognition reported in body dysmorphic disorder, which might point towards cognitive heterogeneity in the disorder. This study aimed to examine the cognitive profile of body dysmorphic disorder in a large sample across eight cognitive domains, and to explore whether cognitive subgroups might be identified within body dysmorphic disorder.

METHOD

Cognitive domains of inhibition/flexibility, working memory, speed of processing, reasoning and problem-solving, visual and verbal learning, attention/vigilance and social cognition were assessed and compared between 65 body dysmorphic disorder patients and 70 healthy controls. Then, hierarchical clustering analysis was conducted on the body dysmorphic disorder group's cognitive data.

RESULTS

Group-average comparisons demonstrated significantly poorer cognitive functioning in body dysmorphic disorder than healthy controls in all domains except for attention/vigilance and social cognition. Cluster analysis identified two divergent cognitive subgroups within our body dysmorphic disorder cohort characterised by (1) broadly intact cognitive function with mild selective impairments (72.3%), and (2) broadly impaired cognitive function (27.7%). However, the clusters did not significantly differ on clinical parameters or most sociodemographic characteristics.

CONCLUSION

Our findings demonstrate considerable cognitive heterogeneity among persons with body dysmorphic disorder, rather than uniform deficits. Poor performances in the broadly impaired subgroup may have driven group-level differences. However, our findings also suggest a dissociation between cognitive functioning and clinical characteristics in body dysmorphic disorder that has implications for current aetiological models. Additional research is needed to clarify why some people with body dysmorphic disorder demonstrate cognitive deficits while others do not.