Anorexia nervosa (AN) is an eating disorder characterized by severely low bodyweight, fear of weight-gain, and a subjective believe to be “fat”. An elevated need for control and fear of losing control are considered core aspects in the development and maintenance of AN and restricting food intake is thought to function as a means to gain feelings of control (Fairburn, Shafran, & Cooper, 1999; Schmidt & Treasure, 2006). Feelings of inefficiency (i.e. lack of control regarding personal goals) have been found to predict longer duration of treatment and worse treatment outcome, underlining the relevance of the need for control in AN (Olatunji, Levinson, & Calebs, 2018; Pinto, Heinberg, Coughlin, Fava, & Guarda, 2008; Surgenor, Maguire, Russell, & Touyz, 2007). The constant striving for control could lead to rumination and negative affect – two further important symptoms associated with AN. The Goal Progress Theory of rumination (GPT; Carver & Scheier, 1990; Martin & Tesser, 1996) proposes that perceived discrepancies between desired goals (in the case of AN e.g. goals regarding lowest possible calorie intake, weight, etc.) and the current state (in the case of AN e.g. the subjective conviction of having eaten or weighing too much) trigger ruminative thoughts, which subsequently lead to negative affect. Following this theory, it could be suggested that gaining feelings of goal-progress and control could lessen the burdening repetitive thoughts and negative affect and that individuals with AN try to achieve this by restricting food intake. This dietary restriction requires self-control. However, previous research has shown that patients with AN typically not only show such elevated self-control, but also display rigid habitual behaviours and routines, struggle with set-shifting, and often display comorbid obsessive-compulsive symptoms (Treasure & Schmidt, 2013; Halmi et al., 2003). This raises the question of whether food restriction in AN is indeed an act of self-control or rather a habit. Recent scientific development has challenged the traditional dichotomy between controlled and automatic processes (Shiffrin & Schneider, 1977), instead suggesting that they are intertwined in such a way that often self-control works via the establishment of goal-serving habits and routines (Gillebaart & de Ridder, 2015; Galla & Duckworth, 2015).
These theoretical considerations can generally draw support from previous research, but have not been investigated explicitly in the context of AN. It was the main goal of this thesis to analyse associations between feelings of inefficiency, rumination and negative affect, controlled and habitual behaviour, and eating behaviour to establish an empirical foundation for the proposed relationships between these aspects of AN.
Study 1 (Fürtjes, Seidel, et al., 2020) employed ecological momentary assessment (EMA; data collection several times a day over a period of several days in the natural environment of the participants) to investigate associations between feelings of inefficiency, rumination, and affect in a sample of individuals with a history of AN who had recovered from the disorder in terms of eating behaviour and bodyweight and age-matched healthy control participants (HC). AN participants displayed elevated rumination about bodyweight/figure (but not food) and negative affect compared to HC, suggesting that these cognitive-affective symptoms are persistent even after recovery. Analyses investigating associations with inefficiency showed that inefficiency was associated with heightened rumination and negative affect, which is in line with the GPT. Furthermore, AN participants showed higher levels of inefficiency than HC and stronger associations between rumination and negative affect. These findings indicate that feelings of lack of goal-progress and control are a central aspect of AN, likely contributing to maintenance of the disorder by triggering dysfunctional cognitive-affective processes. The fact that these associations were still present in a sample of recovered individuals underlines the persistence of these processes, suggesting that they might not only maintain the disorder but could also present a vulnerability factor or contribute to risk of relapse.
Study 2 (Fürtjes et al., 2018) made use of EMA and leptin, an endocrinological marker of undernutrition, to further investigate associations between rumination and affect in a sample of patients with acute AN, once at the beginning of treatment and again after weight-restoration. In line with Study 1, results confirmed that rumination about bodyweight/figure and negative affect are closely linked in AN and that this association persists even after weight-gain. Thoughts about food on the other hand were associated with leptin levels, declined with weight-gain, and showed weaker associations with affect. This suggests that thoughts about food may reflect a physiological symptom of the disorder, connected to undernourishment, whereas thoughts about bodyweight/figure might present a cognitive-affective symptom which could be involved in maintenance of the disorder (as suggested by Study 1).
To test supporting evidence for the interaction of self-control and habits in the regulation of eating behaviour, Study 3 (Fürtjes, King, et al., 2020) employed task-based measures of controlled and automatic processing as well as self-report measures of self-control, habitual behaviour, and eating behaviour in a large female sample representative of the general population through an online study design. Results obtained via structural equation modelling (SEM) revealed that eating behaviour appears to be largely guided by habits and automatic behavioural tendencies, whereas controlled aspects have an indirect influence via this association. These findings could be interpreted as support for the proposal that self-control might work via the establishment of goal-serving habits and routines, which outlines the possibility that the restrictive eating behaviour in AN might be achieved and maintained via a combination of self-control and rigid routines and habits.
Taken together, the research presented in this thesis was able to demonstrate how striving for control as a core aspect of AN might play a role in triggering dysfunctional cognitive-affective processes, likely contributing to development and maintenance of the disorder, and that self-control and habitual behaviour interact inguiding human eating behaviour, carrying implications for the mechanisms behind restrictive eating in AN. Clinical implications that can be derived from this research include addressing need for control and feelings of inefficiency in therapy to enable improvement of dysfunctional cognitive-affective processes as well as eating behaviour.
| Identifer | oai:union.ndltd.org:DRESDEN/oai:qucosa:de:qucosa:75392 |
| Date | 08 July 2021 |
| Creators | Fürtjes, Anna Sophia Margareta |
| Contributors | Ehrlich, Stefan, Beesdo-Baum, Katja, Technische Universität Dresden |
| Source Sets | Hochschulschriftenserver (HSSS) der SLUB Dresden |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, doc-type:doctoralThesis, info:eu-repo/semantics/doctoralThesis, doc-type:Text |
| Rights | info:eu-repo/semantics/openAccess |
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