Environmental risk factors and therapeutical implications in eating disorders

by Krug, Isabel

Abstract (Summary)
SUMMARY: The central scientific objective of this thesis was to take a broad multidisciplinary approach to make use of the full potential information to battle EDs, utilizing an interactive and translational approach running from basic science through to the clinic. In our studies we assessed a.) clinical factors and comorbidity [namely substance use in EDs (Studies 1 to 3)], b.) psychosocial, behavioural and environmental correlates of EDs (Studies 4 to 7) and c.) treatment effectiveness of specific forms of ED interventions (Studies 8 to 9). Our first line of investigation comprised Studies 1 to 3 and assessed the comorbidity of substance use in EDs. The results of these studies suggest that compared to healthy controls, substance use was higher in individuals with EDs (Studies 1 and 3), that the presence of a family history of alcohol dependence was associated with the comorbidity of EDs and substance use (Study 2) that substance use was particularly prevalent in patients with bulimic characteristics (Studies 1 to 3) and that EDs and substance abuse may represent expressions of a fundamental predisposition to addictive behaviour possibly related to the genetically influenced traits such as novelty seeking (Study 2). Furthermore, we revealed some significant differences for the specific forms of drugs in people with EDs (Studies 1 and 3), which emphasize the significance of assessing various drug types in EDs. Finally we also observed cross-cultural differences across various European countries in the prevalence of substance use in EDs and healthy controls (Study 3). The second research area was labelled psychological, behavioural and environmental correlates of EDs. In our animal study (Study 4) we found that contextual conditioning of eating response was more effective when high than low density caloric food was used. This result indicates that animal models are useful for analyzing and identifying human-animal links in feeding related behaviours. Studies 5 and 6 assessed which early individual and family eating patterns play a role in the development of EDs. Our findings agree with the growing body of research indicating that a variety of environmental and social factors are associated with dysfunctional individual and family eating patterns (e.g. food used as individualization, control and rules about food) during the first years of life and which if not detected on time could lead to a subsequent ED. Conversely, healthy eating (including eating breakfast) was negatively linked to the development of a subsequent ED. Only a few differences across ED subtypes were observed. Finally some cross-cultural differences also emerged (Study 6). In Study 7 we compared anger expressions in individuals with EDs and healthy controls and explored the relation among ED symptoms, comorbid psychopathology, personality traits and impulsive behaviours. The results indicated that individuals with EDs obtained significantly higher scores than controls on maladaptive anger expressions. When different purging methods were assessed independently, the frequency of laxative use was associated with anger suppression. ED symptoms and specific personality traits were also positively associated to different anger expressions. At last, we observed that inappropriate anger expressions were related to self-harming behaviours. Finally our last research line assessed the effectiveness of various treatments for EDs. In Study 8 we compared full and subthreshold BN in terms of personality, clinical characteristics and short-term response to a psychoeducational therapy. The results showed that full-BN and sub-BN share common psychopathological symptoms and personality traits. Furthermore, no differences in therapy outcome were observed in terms of general ED symptomatology and psychopathology. In Study 9 we described and assessed a non-symptom oriented CBT treatment in a congenitally blind women. A dramatic reduction in ED symptoms was observed after the maintaining and triggering factors had been reduced. To conclude, relatively little research has been performed towards understanding the aetiology of EDs. The findings from our investigations represent a major enhancement in the state of the art of EDs, and lead to the development of a new overall etiological model of EDs. The model we propose is a general understanding of how various ED predisposing and precipitating factors might eventually lead to EDs, and maintain the course of a disorder. Future work should address the effects of genes, environment and gene-environment interaction on the development and maintenance of EDs. Of specific interest is the query of which of these factors are non-specifically related to mental disorders and which factors may be more explicit factors that predispose an individual to EDs and related states, but not to mental disorders in general. The answers to these questions should hopefully become perceptible in the next couple of years.
This document abstract is also available in Catalan and Spanish.
Bibliographical Information:

Advisor:Fernández Aranda, Fernando; Aguilar Alonso, Ángel

School:Universitat de Barcelona

School Location:Spain

Source Type:Master's Thesis

Keywords:personalitat avaluació i tractament psicològic


Date of Publication:12/05/2008

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