Eating disorders and obsessive-compulsive disorder: an examination of overlapping symptoms, obsessive beliefs, and associated cognitive dimensions
Creators: name: Schembri, Adrian
Publisher: name: RMIT University
Year: 2024

description: For over half a century, researchers and practitioners have documented the statistical comorbidity and overlapping symptom presentation between eating disorders and obsessive-compulsive disorder (OCD). Recent research by the Obsessive-Compulsive Cognitions Working Group (OCCWG) has identified cognitive dimensions salient to OCD, which has prompted researchers to investigate the incidence of obsessive-compulsive cognitions among eating disorder populations. Six beliefs have been identified by the OCCWG, including overestimation of threat, inflated<br>responsibility, perfectionism, intolerance of uncertainty, importance of thoughts, and the need to control thoughts. The aim of the current research was to extend current literature and examine the overlapping and distinguishable features of eating disorders and OCD, placing particular emphasis on cognitions. Obsessive beliefs identified by the OCCWG were compared across diagnostic groups (e.g., eating disorders, OCD, depression) and a community control group. In addressing whether obsessive beliefs among women with eating disorders are specific to the domains of eating, shape, and weight, a new measure was developed. This measure was based on self-report assessments developed by the OCCWG, however in the newly developed measure, items were tailored specifically to the domains of eating, body shape, and weight.<br><br>Eating and anxiety disorder clinics and associations throughout Australia (e.g., The Bronte Centre at St. Vincent’s, the Oak House, the Eating Disorders Foundation of Victoria, and the Anxiety Disorders Association of Victoria) assisted with recruitment for this research. A total sample of 1207 Australian women, aged between 18 and 69 years, was recruited to participate. Participants incorporated both a community and clinical sample, with the clinical sample consisting of 100 women with an eating<br>disorder, 21 with OCD, and 49 with depression. Women with a self-reported history of other Axis I and Axis II DSM-IV disorders were also recruited, however insufficient samples were available to form clinical comparison groups for these forms of psychopathology. Each participant completed a questionnaire package containing a series of self-report measures of eating disorder and OCD symptomatology, obsessive beliefs, self-esteem, body checking behaviours and cognitions, and general symptoms of depression and anxiety.<br><br>Findings of this research are presented across four studies. The first study<br>examined the overlap between eating disorder and obsessive-compulsive<br>symptomatology, with a focus on differences in symptoms across diagnostic categories and whether eating disorder symptoms are associated with subtypes of obsessions or compulsive behaviour. Results indicated that higher scores on a measure of eating pathology were associated with elevated obsessive-compulsive symptoms, particularly on the checking, ordering, obsession, hoarding and mental neutralisation symptom domains of OCD. Findings also revealed that the higher the frequency of disordered eating behaviour, the greater the likelihood of obtaining scores of OCD in the clinical range.<br><br>The second study examined the presence and severity of obsessive beliefs, as measured by the Obsessive Beliefs Questionnaire (OBQ-44), in an eating disorder sample. Moderate to strong associations were found between eating disorder symptoms and general obsessive beliefs. Consistent with previous research, scores on the OBQ-44 were equivalent across clinical groups. Analysis of covariance revealed that a greater proportion of variance in obsessive beliefs was accounted for by obsessive-compulsive symptoms for those women with OCD when compared with their counterparts with an eating disorder or depression.<br><br>Study 3 introduced a new measure of obsessive beliefs that was developed and psychometrically tested for the purposes of the current research. The Obsessive Beliefs Questionnaire – Eating Disorder Version (OBQ-EDV) was designed to provide a measure of obsessive beliefs that was specific to the domains of eating, shape, and weight, given the breadth of research documenting that concerns over shape and weight constitute the core symptomatology underlying eating disorders. The factor structure of the OBQ-EDV was found to be largely consistent with that of the OBQ-44. Item analysis and internal consistency coefficients yielded encouraging results, whilst preliminary investigation of the face, content, criterion-related, and construct validity of the OBQ-EDV was also promising.<br><br>The final study investigated scores on the newly developed OBQ-EDV across clinical and community-based groups. Women with an eating disorder scored higher on the OBQ-EDV total score than the OCD, depression, and community control groups. Women with anorexia nervosa were found to have mildly higher scores on the OBQEDV when compared with their counterparts with bulimia nervosa, however a lack of statistical power due to a small sample size precluded the emergence of any statistically significant findings. Eating, shape, and weight specific obsessive beliefs were found to mediate the relationship between general obsessive beliefs (as measured by the OBQ-44) and eating disorder symptoms.<br><br>In the context of these findings, implications and recommendations for clinical practice are discussed. Directions for future research are also presented, including replication of the current work given that very few studies have examined obsessive beliefs in the context of eating disorders, despite well established relationships between eating disorders and OCD. It is argued that further research is necessary to provide a more concrete rationale for the acknowledgment of obsessive beliefs in treatment models for eating disorders. Findings of the current study provide further support for researchers and practitioners working in the eating disorder field to remain cognisant of the presence of obsessive-compulsive cognitions in this clinical population.<br>