Testing intrusive thoughts as illness pathways between eating disorders and obsessive-compulsive disorder symptoms: a network analysis

Obsessive-compulsive disorder (OCD) and eating disorders (EDs) frequently co-occur. Intrusive thoughts are a mechanism that may maintain this comorbidity. This study used network analysis to identify central ED-related intrusive thoughts and tested which intrusive thoughts connected ED and OCD symptoms. Two cross-sectional graphical LASSO networks were computed using a sample of 353 non-clinical participants (mean age = 35.38, SD = 9.9, 40% female, 81.6% Caucasian) with elevated disordered eating symptoms. Model 1 included just ED-related intrusive thoughts, and Model 2 included ED-related intrusive thoughts, ED, and OCD symptoms. In Model 1, we found that thoughts about one's bodily appearance (i.e., looking horrible, getting fat, gaining weight) were most central. In Model 2, we found that desire to lose weight, eating in secret, and shape dissatisfaction were most central. We identified one illness pathway (i.e., difficulty concentrating due to thoughts of food/calories) connecting intrusive thoughts, ED symptoms, and OCD symptoms. However, intrusive thoughts did not bridge ED and OCD symptoms. Hence, we found some evidence that ED-related intrusive thoughts may contribute to ED and OCD symptoms based on thought content and frequency. However, other aspects of intrusive thoughts should be considered to ascertain whether they do in fact significantly contribute to ED and OCD comorbidity. Prevention efforts targeting ED-related intrusive thoughts may attenuate ED and OCD symptoms among subclinical individuals.

Psychiatric Comorbidity Among Eating Disorders and Obsessive-Compulsive Disorder and Underlying Shared Mechanisms and Features: An Updated Review

Eating disorders (EDs) are highly comorbid with obsessive-compulsive disorder (OCD), with comorbidity rates as high as 41%. In the current review, we summarize the literature regarding the prevalence of ED-OCD comorbidity. We also identify and review the literature assessing shared features (i.e., shared characteristics or symptoms) and mechanisms (i.e., variables that may explain ED or OCD symptoms) of EDs and OCD. Potential shared features of EDs and OCD include age of onset, course of illness, obsessions, compulsions and ritualistic behaviors, and thought action fusion. Shared mechanisms that may explain ED-OCD comorbidity include genetic and neurobiological mechanisms, anxiety and fear, repetitive negative thinking, perfectionism, intolerance of uncertainty, distress tolerance, and impulsivity. Based on these shared features and mechanisms, a theoretical conceptualization of ED and OCD comorbidity is developed, and outline considerations for assessment, differential diagnosis, treatment, and future research regarding ED-OCD comorbidity are described.

What can we learn about the psychiatric diagnostic categories by analysing patients' lived experiences with Machine-Learning?

BACKGROUND

To deliver appropriate mental healthcare interventions and support, it is imperative to be able to distinguish one person from the other. The current classification of mental illness (e.g., DSM) is unable to do that well, indicating the problem of diagnostic heterogeneity between disorders (i.e., the disorder categories have many common symptoms). As a result, the same person might be diagnosed with two different disorders by two independent clinicians. We argue that this problem might have resulted because these disorders were created by a group of humans (APA taskforce members) who relied on more intuition and consensus than data. Literature suggests that human-led decisions are prone to biases, group-thinking, and other factors (such as financial conflict of interest) that can enormously influence creating diagnostic and treatment guidelines. Therefore, in this study, we inquire that if we prevent such human intervention (and thereby their associated biases) and use Artificial Intelligence (A.I.) to form those disorder structures from the data (patient-reported symptoms) directly, then can we come up with homogenous clusters or categories (representing disorders/syndromes: a group of co-occurring symptoms) that are adequately distinguishable from each other for them to be clinically useful. Additionally, we inquired how these A.I.-created categories differ (or are similar) from human-created categories. Finally, to the best of our knowledge, this is the first study, that demonstrated how to use narrative qualitative data from patients with psychopathology and group their experiences using an A.I. Therefore, the current study also attempts to serve as a proof-of-concept.

METHOD

We used secondary data scraped from online communities and consisting of 10,933 patients' narratives about their lived experiences. These patients were diagnosed with one or more DSM diagnoses for mental illness. Using Natural Language Processing techniques, we converted the text data into a numeric form. We then used an Unsupervised Machine Learning algorithm called K-Means Clustering to group/cluster the symptoms.  RESULTS: Using the data mining approach, the A.I. found four categories/clusters formed from the data. We presented ten symptoms or experiences under each cluster to demonstrate the practicality of application and understanding. We also identified the transdiagnostic factors and symptoms that were unique to each of these four clusters. We explored the extent of similarities between these clusters and studied the difference in data density in them. Finally, we reported the silhouette score of + 0.046, indicating that the clusters are poorly distinguishable from each other (i.e., they have high overlapping symptoms).

DISCUSSION

We infer that whether humans attempt to categorise mental illnesses or an A.I., the result is that the categories of mental disorders will not be unique enough to be able to distinguish one service seeker from another. Therefore, the categorical approach of diagnosing mental disorders can be argued to fall short of its purpose. We need to search for a classification system beyond the categorical approaches even if there are secondary merits (such as ease of communication and black-and-white (binary) decision making). However, using our A.I. based data mining approach had several meritorious findings. For example, we found that some symptoms are more exclusive or unique to one cluster. In contrast, others are shared by most other clusters (i.e., identification of transdiagnostic experiences). Such differences are interesting objects of inquiry for future studies. For example, in clear contrast to the traditional diagnostic systems, while some experiences, such as auditory hallucinations, are present in all four clusters, others, such as trouble with eating, are exclusive to one cluster (representing a syndrome: a group of co-occurring symptoms). We argue that trans-diagnostic conditions (e.g., auditory hallucinations) might be prime targets for symptom-level interventions. For syndrome-level grouping and intervention, however, we argue that exclusive symptoms are the main targets.

CONCLUSION

Categorical approach to mental disorders is not a way forward because the categories are not unique enough and have several shared symptoms. We argue that the same symptoms can be present in more than one syndrome, although dimensionally different. However, we need additional studies to test this hypothesis. Future directions and implications were discussed.

Obsessive-compulsive symptoms in young women affected with anorexia nervosa, and their relationship with personality, psychopathology, and attachment style

PURPOSE

Obsessive-compulsive symptoms (OC) are associated with greater morbidity and worse prognosis in anorexia nervosa (AN). We assessed the presence of non-eating OC in participants with AN and related them with their psychopathology, personality, and attachment style features.

METHODS

Young women with AN (N = 41, 30 restrictor and 11 binge-purging type) were assessed on the Yale-Brown Obsessive-Compulsive Scale (Y-BOCS). These participants with AN and 82 healthy controls (HC) completed the Temperament and Character Inventory (TCI), Eating Disorder Inventory-2 (EDI-2), Symptom Checklist-90 (SCL-90), Toronto Alexithymia Scale (TAS-20), and Attachment Style Questionnaire (ASQ). The association between Y-BOCS scores and indexes of psychopathology, personality, and attachment were examined.

RESULTS

AN had significantly higher scores than HC on the EDI-2, SCL-90, TAS-20, ASQ-Need for Approval, and TCI-Harm Avoidance and Self-directedness. The Y-BOCS scores were significantly correlated with ASQ-Need for Approval, TAS-20-Difficulty in Describing Feelings, SCL-90-Phobic Anxiety, and Anxiety, EDI-2-Drive to Thinness, and Asceticism. Need for Approval displayed the strongest correlation with OC symptoms. Difficulty in describing feelings displayed the strongest correlation with compulsive OC symptoms.

CONCLUSIONS

OC traits in AN were primarily associated with measures of insecure attachment rather than to their eating disorder or general psychopathology. Therapeutic approaches to correcting insecure attachment may be considered as a possible approach to treating AN patients with OC. The study supports a new psychopathological perspective for understanding the meaning of OC symptoms in AN.

LEVEL OF EVIDENCE

III: Evidence obtained from cohort or case-control analytic studies.

Examining weekly relationships between obsessive-compulsive and eating disorder symptoms

BACKGROUND

Despite the severity and high rate of co-occurrence between eating disorders (ED) and obsessive-compulsive disorder (OCD), less is known regarding the longitudinal sequencing of their comorbidity and whether and how their symptoms may influence one another over time. The current study sought to answer these questions by testing if a bidirectional, longitudinal relationship exists between ED symptoms and OCD obsessions and compulsions.

METHODS

We examined the relationship between ED symptoms, obsessions and compulsions across five time points, each one week apart using auto-regressive cross-lagged panel modeling. The final sample consisted of 358 individuals from the community with moderate levels of ED and OCD symptoms, the majority of whom identified as White and male.

RESULTS

Bivariate correlations revealed that ED symptoms, obsessions and compulsions were associated with one another across the five weeks. Two cross-lagged panel models indicated that ED symptoms predicted OCD symptoms at numerous time points and vice versa. However, we found this significant longitudinal associations across only certain weeks. Notably, the models found that only ED symptoms and OCD obsessions predicted one another across different time points across the five weeks; ED symptoms and OCD compulsions did not predict one another.

LIMITATIONS

Due to the non-clinical nature of the sample, there is limited generalizability to clinical populations.

CONCLUSIONS

Our results provide preliminary evidence that there is a bidirectional, longitudinal relationship between ED symptoms and OCD symptoms among a community sample, particularly with respect to cognitive as opposed to behavioral symptoms.

Gender differences in eating disorder-related intrusive thoughts

The present study aimed to examine gender differences in the experience of eating disorder-related intrusive thoughts (EDITs; i.e., frequency, content, emotional consequences, & control strategies). In addition, differences in the experience of EDITs across those atrisk of developing an eating disorder and those who are not atrisk were investigated. Six hundred and seventy-one adults completed self-report measures assessing the experience of EDITs, disordered eating attitudes and behaviours, and body dissatisfaction. It was found that females experienced EDITs more frequently and with higher levels of distress compared with males. With regard to control strategies, females tended to use distraction and thought suppression, whereas males were likely to do nothing in response. Participants in the at-risk group experienced EDITs more frequently, with higher distress, and responded by using obsessive-compulsive rituals or doing what the intrusion dictated significantly more than non-risk participants. Relationships between body dissatisfaction and EDITs related to bodily appearance were found to be stronger for men, whereas women revealed a stronger relationship between disordered eating and purging EDITs. The findings of this study support the growing literature regarding EDITs as a distinct clinical feature of eating disorders, and the developing evidence base regarding intrusive thoughts as a transdiagnostic mechanism.

Functional links of obsessive, dysmorphic, hypochondriac, and eating-disorders related mental intrusions

Unwanted mental intrusions (UMIs) are the normal variants of obsessions in Obsessive-Compulsive Disorder (OCD), preoccupations about defects in Body Dysmorphic Disorder (BDD), images about illness in Hypochondriasis (HYP), and thoughts about eating in Eating Disorders (EDs). The aim was to examine the similarities and differences in the functional links of four UMI contents, adopting a within-subject perspective. Method: 438 university students and community participants (M _age = 29.84, SD = 11.41; 70.54% women) completed the Questionnaire of Unpleasant Intrusive Thoughts (QUIT) to assess the functional links (emotions, appraisals, and neutralizing/control strategies) of the most upsetting UMIs with OCD, BDD, HYP and EDs-contents. Results: HYP-related intrusions caused the highest emotional impact, OCD-related intrusions were the most interfering, and EDs-related intrusions interfered the least. The four UMI were equally ego-dystonic. Women appraised OCD-related intrusions more dysfunctionally, but men appraised the four intrusive contents similarly. All UMI instigated the urge to "do something", to keep them under control and/or neutralizing them. Conclusions: Similarities among the functional links of intrusions related to OCD, BDD, HYP and EDs contents support their transdiagnostic nature and they might contribute to understanding common factors in these disorders.

When food becomes an obsession: Overweight is related to food-related obsessive-compulsive behavior

In this study, it was examined whether overweight is associated with food-related obsessions and compulsions. Participants with a healthy weight (n = 27) and participants who were overweight (n = 33) filled out the Yale-Brown-Cornell Eating Disorder Scale, the Eating Obsessive-Compulsive Scale, and the Emotional and Behavioral Reactions to Intrusions Questionnaire to assess frequency, distress, control, and reactance associated with food-related preoccupations and compulsions. Overweight participants showed increased food-related preoccupations, compulsive eating, and heightened emotional and behavioral reactance compared to participants with a healthy weight. Increased food-related obsessive-compulsiveness was also associated with unhealthy eating patterns.

Brain connectome modularity in weight-restored anorexia nervosa and body dysmorphic disorder

BACKGROUND

Anorexia nervosa (AN) and body dysmorphic disorder (BDD) frequently co-occur, and have several overlapping phenomenological features. Little is known about their shared neurobiology. The aim of the study was to compare modular organization of brain structural connectivity.

METHOD

We acquired diffusion-weighted magnetic resonance imaging data on unmedicated individuals with BDD (n = 29), weight-restored AN (n = 24) and healthy controls (HC) (n = 31). We constructed connectivity matrices using whole-brain white matter tractography, and compared modular structures across groups.

RESULTS

AN showed abnormal modularity involving frontal, basal ganglia and posterior cingulate nodes. There was a trend in BDD for similar abnormalities, but no significant differences compared with AN. In AN, poor insight correlated with longer path length in right caudal anterior cingulate and right posterior cingulate.

CONCLUSIONS

Abnormal network organization patterns in AN, partially shared with BDD, may have implications for understanding integration between reward and habit/ritual formation, as well as conflict monitoring/error detection.

Confirmatory factor analysis and psychometric properties of the Yale-Brown-Cornell Eating Disorders Scale Self-Report version (SR-YBC-EDS) in Spanish clinical and non-clinical samples

OBJECTIVE

The aim of the study was to adapt and validate the Yale-Brown-Cornell Eating Disorder Scale (YBC-EDS) transformed into a self-report format in Spanish clinical and non-clinical samples.

METHOD

Eighty-three eating disordered patients and 358 non-clinical participants completed the Self Report-YBC-EDS version (SR-YBC-EDS), the Eating Attitudes Test (EAT), and the Penn State Worry Questionnaire (PSWQ).

RESULTS

Confirmatory factor analyses of a two-factor second-order model showed adequate values of goodness-of-fit indices for non-clinical (normed χ(2)=13.4578; df =18; NFI=0.980; GFI=1.00; RMSEA=0.00) and clinical samples (normed χ(2)=26.5913; df =18; NFI=0.944; GFI=0.981; RMSEA=0.076). The factor loadings were high (preoccupations range: 0.69-0.91; rituals range: 0.61-0.94). Cronbach's alpha (range α=0.85-0.90) and test-retest 2weeks later (range: 0.84-0.91) were excellent in both samples. SR-YBC-EDS showed moderate-high indices of convergent validity with PSWQ and EAT. For the total score, a cutoff of 13 showed a sensitivity of 90.4%, a specificity of 91.6%, and a diagnostic accuracy of 91.4%. Positive and negative predictive values were excellent (71.4% and 97.6%, respectively).

DISCUSSION

Findings indicate that the SR-YBC-EDS is a reliable and valid instrument to identify symptoms and assess the severity of ED, and it can be used as a faster and less costly alternative to the YBC-EDS interview.

Intrusive thoughts in obsessive-compulsive disorder and eating disorder patients: a differential analysis

The present study aims to compare the unwanted intrusions experienced by obsessive-compulsive (OCD) and eating disorder (ED) patients, their appraisals, and their control strategies and analyse which variables predict the intrusions' disruption and emotional disturbance in each group. Seventy-nine OCD and 177 ED patients completed two equivalent self-reports designed to assess OCD-related and ED-related intrusions, their dysfunctional appraisals, and associated control strategies. OCD and ED patients experienced intrusions with comparable frequency and emotional disturbance, but OCD patients experienced greater disruption. Differences appeared between groups on some appraisals and control strategies. Intolerance to uncertainty (OCD group) and thought importance (ED group) predicted their respective emotional disturbance and disruption. Additionally, control importance (OCD group) and thought-action fusion moral (OCD and ED groups) predicted their emotional disturbance. OCD and ED share the presence of intrusions; however, different variables explain why they are disruptive and emotionally disturbing. Cognitive intrusions require further investigation as a transdiagnostic variable.

Ego-syntonicity and ego-dystonicity of eating-related intrusive thoughts in patients with eating disorders

The main objective of the present study was to analyse the role of the ego-dystonicity and ego-syntonicity of eating disorder intrusive thoughts (EDITs) in the genesis and maintenance of eating disorders (EDs). Participants were 98 female patients with EDs, 56 Spanish and 42 English (27.19±9.59 years; body mass index (BMI): 18.72±2.87). All of them completed the eating attitudes test, the Eating Attitudes Test, the Eating Intrusive Thoughts Inventory, the Ego-Dystonicity Questionnaire-Reduced version, and the Ego-Syntonicity Questionnaire. Patients indicated that their EDITs were rational and also undesirable and immoral, suggesting that EDITs are not fully ego-syntonic or ego-dystonic. Multivariate analysis of variance (MANOVA) indicated no differences in ego-syntonicity and ego-dystonicity across ED subtypes. Path analyses were performed to investigate the mediating role of the EDITs' ego-syntonicity and ego-dystonicity in their interference, dysfunctional appraisals and control strategies. They showed, first, that the more interference an EDIT caused, the more ego-syntonic and the less ego-dystonic it was and, second, that when the EDITs were assessed as ego-syntonic, patients tried to do what they indicated, whereas when they were assessed as ego-dystonic, patients made efforts to neutralise them. Clinical implications for the conceptualisation and treatment of ED are discussed.