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Cognitive distortions in eating disorders: Development and application of a model for thought-shape fusion

Final Report Summary - THOUGHT-SHAPE FUSION (Cognitive distortions in eating disorders: development and application of a model for thought-shape fusion)

Project objectives

Cognitive distortions are characterised by faulty, irrational thought processes, and are characteristic of psychopathology, including obsessive-compulsive disorder (OCD) and eating disorders. Within the past decade, new research has emerged which suggests that there is a specific cognitive distortion associated with eating disorders; this distortion has been identified as 'thought-shape fusion' (TSF), and is associated with the belief that just thinking about fattening foods can lead to weight gain, feelings of fatness, and perceived moral wrong-doing. The clinical significance and implications of this cognitive distortion have yet to be systematically studied; however, identifying and addressing distortions such as TSF may be beneficial for the sizeable number of individuals with eating disorders who do not respond well to therapy. The proposed project investigated the mechanisms underlying cognitive distortions, and the role that TSF plays in eating disorders.

The main objectives of this project were:

(1) to investigate the psychological and behavioural effects of inducing TSF in individuals with eating disorders, and to establish whether individuals with OCD are also particularly susceptible to the experience of TSF;
(2) to determine whether TSF decreases after psychological treatment for eating disorders; and
(3) to investigate the possible mechanisms that are involved in TSF.

Research studies

Three studies were conducted over the course of the project (16 months):

Study 1:
An experimental study investigated the effects of inducing TSF (vs. a neutral induction) in three groups of women: women in treatment for an eating disorder, women in treatment for OCD, and a group of healthy controls who had no history of an eating disorder or OCD. Individuals who were exposed to the TSF induction were asked to imagine eating a high-caloric / fattening food. Those exposed to the neutral induction were asked to imagine a neutral situation (being in a park). The participants' cognitions and behaviour in response to the induction were assessed. Furthermore, we evaluated whether their general susceptibility to the TSF remained stable over time by conducting a follow-up assessment three months after their initial appointment.

Study 2:
A study was conducted to assess the links between cognitive distortions, eating pathology, and obsessive-compulsive beliefs in a large sample of young adults. Participants completed a questionnaire package which assessed their levels of TSF, eating pathology, body dissatisfaction, obsessive beliefs, and depression.

Study 3:
An experimental study was conducted to further investigate the possible mechanisms of TSF, by studying whether TSF could be induced in young adolescents. We further investigated whether TSF was present across the spectrum of eating pathology, by recruiting participants who were currently in treatment for obesity (many of whom exhibited loss of control over eating) and a healthy comparison group.

Main results

Study 1:
As expected, individuals with eating disorders were much more susceptible to inductions of TSF than were healthy controls. After the TSF induction, individuals with eating disorders had higher levels of TSF, were more likely to try to reduce the effects of having imagined eating a fattening food, were more distressed, and had higher levels of negative affect.

Individuals with OCD did not appear to be particularly susceptible to the TSF induction, as they reported significantly less distress than both individuals with eating disorders and healthy controls did after imagining eating a fattening food. This finding is interesting, as previous research has indicated that individuals with eating disorders often exhibit increased susceptibility to obsessive beliefs. The current research suggests that the reverse pattern does not exist. The precise reason for this finding remains unclear, though it is suggestive that there is specificity in eating-related cognitive distortions (and that TSF is not related to general psychopathology).

The preliminary follow-up data suggests that TSF is relatively stable over time, as individuals with eating disorders and healthy controls did not report significant changes in TSF 3 months after their initial appointment.

Study 2:
As expected, there was a significant relationship between TSF and obsessive beliefs, eating pathology, and body dissatisfaction. Preliminary results suggest that the link between TSF and eating pathology is partially mediated by body dissatisfaction. In other words, it appears that TSF leads to body dissatisfaction, which in turn plays a role in eating pathology.

Study 3:
It appears that TSF is also present in young adolescents, as the results indicated that there was a significant effect of inducing TSF on subsequent TSF-related thoughts. Preliminary results also suggest that obese adolescents who were currently inpatients in a weight-loss treatment facility appeared to have different food-related desires after TSF induction than did the control adolescents. More specifically, obese adolescents reported wanting a significant bigger lunch (and more desserts) after TSF induction than did the control adolescents.

Expected final results and implications

While the final results of these three projects are still pending, the preliminary analyses suggest that TSF may play important role in eating pathology. Given that a substantial number of patients with eating disorders do not recover after current treatment methods, and the fact that eating disorders have the highest mortality rate of all psychiatric disorders, it is critical to improve the treatment outcome. The current results suggest that it may be important to focus more on cognitive distortions, such as TSF, over the course of treatment. Furthermore, these results suggest that obese individuals may also be susceptible to TSF and exhibit maladaptive eating behaviour after thinking about fattening foods. The current epidemic levels of overweight / obesity, and the public interest in reducing the prevalence of this condition further substantiates the possible implications and relevance of this project across the spectrum of eating pathology.

Contact details

Scientist in charge: Professor Martine Bouvard ( via e-mail)
Researcher: Jennifer Coelho ( via e-mail)