An investigation of the bodily self in eating disorders

The overall objective of this thesis was to examine whether individuals affected with an eating disorder (ED) have an altered experience of the bodily self in comparison to healthy control (HC) individuals. The secondary objective was to assess whether this hypothesised disturbance could be a state or trait phenomenon. This thesis proposes a transdiagnostic biopsychosocial model of the bodily self in EDs. The first three studies of the thesis used the rubber hand illusion (RHI) paradigm, which involves the illusion of ownership of a fake hand, to examine the proposed model. In the first study, it was found that individuals with an ED (n = 78) experienced the RHI (both perceptually and cognitively) significantly more strongly than the HC participants (n = 61). Individual differences in the experience of the RHI were significantly related to ED psychopathology, and the experience of the RHI was significantly predicted by interoceptive deficits and self-objectification after controlling for other ED and general psychopathology constructs. The second study extended on this study to examine whether these findings indicate a state or trait disturbance, by examining the RHI in individuals who had recovered from an ED (n = 28). Recovered individuals were intermediate to the acutely ill and HC group in the perceptual domain, whereas the recovered individuals were similar to acutely ill individuals in the cognitive domain, suggestive of a trait disturbance. The third study examined the effect of emotional distress on the experience of the bodily self as indexed by a modified version of the RHI task including an emotion induction component (e-RHI task). Emotional distress (whether in the form of body dissatisfaction or general distress) was not found to significantly alter the experience of the bodily self in those with an ED relative to HC individuals. The fourth study took a different methodological approach from the previous three studies and used a heartbeat detection task (HBDT) to focus specifically on interoception. The findings did not demonstrate significant differences between the ED and HC groups on interoceptive sensitivity as indexed by the HBDT. However, the HBDT did not appear to be a valid measure in this sample as floor effects were demonstrated. Overall, these findings provided preliminary support for the proposed model of an altered experience of the bodily self in individuals with an ED and the correlates of this disturbed bodily self. The findings from using the RHI task indicated an increased malleability of the bodily self in acutely affected individuals, with some evidence that this is a trait phenomenon also present in individuals recovered from an ED. More specifically, these studies provide evidence that heightened sensitivity to visual information about the body and reduced somatosensory information processing of the body are present in individuals with an ED as well as in recovered individuals, and are suggestive of a trait phenomenon. This thesis identifies the need for further research in this area, with the ultimate aim of translating these findings into clinical approaches for addressing body disturbances

Classifying excessive exercise: Examining the relationship between compulsive exercise with obsessive‐compulsive disorder symptoms and disordered eating symptoms

Objective: There remains a lack of consensus around nosology for compulsive exercise (CE). Although widely observed in eating disorders (ED), CE shares theoretical overlap with obsessive‐compulsive disorder (OCD), where exercise compulsions occur in response to obsessions. Yet, there is limited and mixed evidence of a relationship between CE with OCD. This study aims to explore the appropriate diagnostic classification of CE through examination of CE in relation to OCD, obsessional thinking, and ED symptoms. Method: Two hundred and eighty one adults with mental health symptoms, dieting, and exercise behaviour completed measures of OCD, CE, and disordered eating symptoms. Regression and Receiver Operating Characteristic analyses examined relationships between dimensions of CE with OCD and ED symptoms, and the predictive ability of CE assessment for detecting threshold OCD and ED symptoms. Results: CE assessment was poor at predicting threshold OCD symptoms, probable Anorexia Nervosa, and Binge Eating Disorder and moderate at detecting probable disordered eating and Bulimia Nervosa. Associations between CE and OCD symptoms were not significant after adjustment for ED symptoms. Obsessional thinking was associated only with lack of exercise enjoyment. Conclusions: Results indicate that excessive exercise might represent a distinct disorder, with some shared traits across CE, OCD and ED symptoms. Findings question the utility of adaptation of OCD diagnostic criteria for CE. Assessment and treatment implications are considered

The Effect of Self-Focused Attention and Mood on Appearance Dissatisfaction after Mirror-Gazing: An Experimental Study

Background and objectives: Self-focused attention is hypothesized to be a maintenance factor in body dysmorphic disorder (BDD). The aim of this study was to use an experimental paradigm to test this hypothesis by studying the effect of self-focused attention during mirror-gazing on appearance dissatisfaction. Methods: An experimental group design was used, in which 173 women were randomly allocated to one of three conditions before mirror-gazing for 2 min: (a) external focus of attention, (b) self-focus of attention, and (c) self-focus of attention with a negative mood induction. Results: After mirror-gazing, participants across all groups rated themselves as being more dissatisfied with their appearance. In both the self-focus conditions, there was an increase in sadness from pre to post mirror gazing, and there was a significant difference in focus of attention for participants in the self-focused, mood-induced group from pre to post manipulation, suggesting mood induction had more of an effect than focus of attention. Limitations: (1) there was no condition involving an external focus with a negative mood induction, and (2) due to the level of information provided to patients on the nature of the task, we cannot rule out demand characteristics as an influencing factor on our results. Conclusions: Self-focused attention during mirror-gazing may act indirectly to increase appearance dissatisfaction via the effect of negative mood. Further studies are required to establish the relative contribution of self-focused attention and negative mood to increases in appearance dissatisfaction as a function of mirror-gazing

Eating Disorder Day Programs: Is There a Best Format?

The use of a Day Program (DP) format (i.e., intensive daily treatment with no overnight admission) has been shown to be an effective treatment for eating disorders (EDs). The disadvantages, however, include higher cost than outpatient treatment (including costs of meals and staff), greater disruption to patients’ lives, and the use of a highly structured and strict schedule that may interrupt the development of patients’ autonomy in taking responsibility for their recovery. This study investigated whether reducing costs of a DP and the disruption to patients’ lives, and increasing opportunity to develop autonomy, impacted clinical outcomes. Three sequential DP formats were compared in the current study: Format 1 was the most expensive (provision of supported dinners three times/week and extended staff hours); Format 2 included only one dinner/week and provision of a take-home meal. Both formats gave greater support to patients who were not progressing well (i.e., extended admission and extensive support from staff when experiencing feelings of suicidality or self-harm). Format 3 did not provide this greater support but established pre-determined admission lengths and required the patient to step out of the program temporarily when feeling suicidal. Fifty-six patients were included in the analyses: 45% were underweight (body mass index (BMI) < 18.5), 96.4% were female, 63% were given a primary diagnosis of anorexia nervosa (or atypical anorexia nervosa), and mean age was 25.57 years. Clinical outcomes were assessed using self-reported measures of disordered eating, psychosocial impairment, and negative mood, but BMI was recorded by staff. Over admission, 4- and 8-week post-admission, and discharge there were no significant differences between any of the clinical outcomes across the three formats. We can tentatively conclude that decreasing costs and increasing the opportunities for autonomy did not negatively impact patient outcomes, but future research should seek to replicate these results in other and larger populations that allow conclusions to be drawn for different eating disorder diagnostic groups

The Appearance Anxiety Inventory:Validation of a Process Measure in the Treatment of Body Dysmorphic Disorder

Background: At present there are no measures to identify the cognitive processes and behaviours that might mediate the outcome of treatment in people with Body Dysmorphic Disorder (BDD). Aims: To develop and validate a process measure that can be used to assess the progress of patients throughout therapy and in research for BDD. Method: The psychometric properties of the Appearance Anxiety Inventory (AAI) were explored in a clinical group of participants diagnosed with BDD (Study 1) and in a non-clinical community group with high appearance concerns (Study 2). Item characteristics, reliability, and factor structure were analysed. Convergent validity with measures of related symptoms was assessed. Results: The AAI was found to have good test-retest reliability and convergent validity in the measurement of appearance anxiety. It was also sensitive to change during treatment. The scale was found to have a two-factor structure in the clinical group, with one factor characterized by avoidance, and a second factor comprised of threat monitoring. However, in the community sample it appeared to have a one-factor structure. Conclusion: The results suggest that the AAI has the psychometric properties to determine whether changes in cognitive processes and behaviours can mediate the outcome following treatment in patients with BDD. This supports its potential usefulness in clinical and research settings.</jats:p