(7) Cognitive Theory and Anorexia Nervosa

Distortions: Cognitive distortions = errors in thinking that cause the individual to develop a negative body image. May be from comparing themsleves to others in term of how they look/how much they eat. Leads to them thinking they must be overweight, leading to self-disgust and attempt to lose weight.

Irrational Beliefs: Individuals frequently develop self-defeating habits due to faulty beliefs about themselves/the world around them. Rational beliefs based on fact/logic - irrational beliefs aren't and are unreaslitic. Typical irrational belief from someone with AN = they must be thin for others to like them/blame social exculsion on their weight.

A cognitive behavioural model of AN (Ganer and Bemis): Recognised AN patients tent to have several characteristics in common. eg. high-acheiving perfectionists, introverted, full of self-doubt. These coupled with exposure to cultural ideals of thinness lead to the forming ideas about the importance of body weight/shape. Results in them developing the irrational belief that losing weight = reduced distress. Losing weight becomes self-reinforcing because of the sense of achievement/positive comments - results in an increase of anxiety around eating - develops into fear or food/weight gain = food avoidance becomes the norm. They become more socially isolated = views their thinking as normal which cnvinces them control over weight is desirable.

The Transdiagnostic Model (Fairburn et al.): Suggest the underlying cause of all ED'd is the same set of cognitive distortions - refered to as 'core psychopathology' - involves the overestimation of bodyweight, apperance and emphasis on self-control which Fairbun believed to be the cetral factor in an. A person with AN's self-esteem  in primarily determined by their weight and appearance and their ability to control these. The characteristic of those with AN is maintained by these 3 mechanisms:

1. An enhanced sense of self-control (eating very little) = increased self-esteem (positive reinforcement).

2. The physiologial and psychological changes they experience as a results of their starvation (intesified hunger) are seen as being the result of failures in self-control = more intensified food restriction.

3. Because of focus on weight and appearance, individual engages in increased monitoring of weight (regular weight checking etc.) any weight gain/slow weight loss leads to increased effors to restricting food to re-gain self-contorol/esteem

Research support for the role of cognitive factors in AN: Lang et al - support for the role of cognitive factors in AN. Compared the performance of 41 children/teens diagnosed with AN with 43 healthy controls on a range of neuropsychological measures. Results: No differences in IQ between the groups. However, the AN individuals showed a more inflexible/inefficient cognitive processing style - eg. those with AN less able to change beliefs/habits even when given new information. Inefficient cognitive processing in the AN group was separate to any clinical/demographic factors. Suggest it represented an underlying characteristic of AN.

Support from Stroop test studies: Researchers predict that the attention of a person with AN will be biased to stimuli related to fatness/fattening food because they are percieved to be more threatening to people with ED. Ben-Tovim et al - 'food Stroop' test. Results: Patients with AN found it harder to colour-name words that were relevant to their weight concerns - suggest selective concentration with those stimuli/words related to them.

CBT-E Support from the success of therapy: Treatment designed to address cognitive problems in ED's. Fairburn et al compared CBT-E to interpersonal psychotherapy (IPT) (treatment with no cognitive element). 130 with EDs randomised to CBT-E or IPT. After 20wks - 2/3s of CBT-E participants met criteria for remission - only 1/3 of IBT did. Indicates the CBT-E is an effective treatment for majority of people with ED - shows cognitive issues are a root of AN. 

Methodological limitation of cognitive theories of AN: Viken et al claim a limitation of cognitive theories of AN is that research over-relies on self-reports of cognitive processing. Assumption that a pre-occupation with thoughts of weight/thiness is able to be tested in verbal self-report - but self-reported cognitions are assessed in retrospect with the assumption that individuals can accurately represent cognitions they have had previously. Most cognitive scientists have rejected this approach. Suggests understanding of the cognitive distortions in AN are limited because of the problems in the methods used.

Limitations of the cognitive approach: Cooper claims cognitive models of AN are the result of clinical observation - not based on empirical research - says there has been little research that tests the hypothesis from cognitive models of AN, many of them have methodological problems over-reliance on self-report questionnaires). As a rsult the development of a cognitive approach to AN has lagged behind the development of it in other disorders (depression).