Week Eight: Bulimia Nervosa

Diagnostic criteria for Bulimia Nervosa

• Recurrent episodes of binge eating

  • Eating at one sitting an abnormally large amount of food

  • Perception of lack of control over eating

• Recurrent inappropriate compensatory behaviour

• Occurring at least twice per week over three months period

• Self-evaluation is unduly influenced by body shape and weight

• Not occurring exclusively in context of Anorexia Nervosa.

Prevelence of BN

•  1-3% lifetime prevalence

• 10x more common in females than males

Course of BN

• Onset typically in late adolescence or early adulthood.

• Chronic and intermittent courses seen

  • There are chronic versions 

  • There are episodic versions

Less sever BN

Binging without compensatory behaviour

Medium severity BN

Binging and engaging in compensatory exercise but not vomiting or using medication to purge

Severe BN

The full range – Binging, purging and compensation behaviour

Cognitive-Behavioural Conceptualisation of Bulimia

• Psychosocial influences

  • Current cultural milieu

    • Correlation between cultural pressure to be thin and ED prevalence, across and within cultural groups (Hsu, 1990).

  • Family factors

  • Vulnerability factors (Fairburn et al., 1997)

• Some authors have argued similarity between BN and OCD (see Rubenstein, 1995)

  • BN patients show higher levels of obsessional traits than normal controls.

CBT Model of BN

Cognitive Model of Bulimia

• Individuals with Bulimia are thought to have a broad negative self-evaluation 

• Extreme concerns about shape and weight 

• Treatment generally starts at the bottom 

  • Negative self-evaluation is the root cause so if left untreated it can re-emerge 

  • Starts by relinquishing compensatory behaviour 

  • Then binge eating 

  • Then rigid dieting 

  • Then concerns about shape and weight 

    • Help them create new ideas about shape and weight 

  • Then negative self-evaluation 

The Role of Dieting in Bulimia

• Dieting behaviour is a risk factor for BN.

  • In 15 year-old schoolgirls, those who diet were 8 times more likely to develop an eating disorder within a one-year period than those who did not restrict food intake.

  • But dieting was not a sufficient factor alone in BN. Only 20% of those dieting went on to develop an ED. (Patton et al., 1990)

    • Diet is an additional factor that increases the likelihood of an eating disorder

• Patients consistently report the onset of binge eating behaviour following a period of dieting.

Treatment outcome of BN

• Whittal,  Agras, & Gould (1999)

  • Meta analysis of 26 studies evaluating CBT with BN. (N=460)

  • Found effect sizes of 1.22 to 1.35 of CBT on

    • CBT seems to have a significant positive effect on treating BN + large effect size

      • Also has positive outcomes for: Binge eating, Purging, Depression symptoms, Eating attitudes

• Hay & Bacaltchuk (2000) Cochrane Review

  • Identified 21 controlled studies of BN

  • Compared CBT vs no treatment, delayed treatment, alternative psychotherapy, self-help CBT.

  • CBT found to be superior to no treatment or delayed treatment

  • CBT approached significance in comparison to other psychotherapies

• BN is the eating disorder with the most research into treatment outcome, and treatment outcome studies of the highest quality.

• Response rates are generally reported at around 50% (clinically significant improvement and treatment response)  (Wilson, Fairburn & Agras, 1997)

• Cognitions must be addressed in addition to behavioural techniques to prevent relapse (Cooper & Steere, 1995)

• Anderson & Maloney (2001) were critical of the use of bingeing and purging behaviour as the only outcome measure and reported variable findings of the impact of CBT on core cognitive symptoms

What is the role of CBT in treatment for of BN

• CBT seems to have a significant positive effect on treating BN + large effect size

  • Also has positive outcomes for: Binge eating, Purging, Depression symptoms, Eating attitudes

• CBT found to be superior to no treatment or delayed treatment

• CBT approached significance in comparison to other psychotherapie

How is relapse prevented for BN

• Cognitions must be addressed in addition to behavioural techniques to prevent relapse (Cooper & Steere, 1995)

What is the reponse rate for BN

Response rates are generally reported at around 50%

T/F Individuals with Bulimia Nervosa are typically emaciated and significantly underweight for their height.

False

T/F Dieting is associated with increased risk of BN

True

What is the key diagnostic characteristic of Binge Eating Disorder (BED)?

• Eating large amounts of food within a short time (within 2 hours)

• Feeling a sense of loss of control (feelings like you can’t stop)

• Compensatory behaviours are not required

Are compensatory behaviors required for the diagnosis of Binge Eating Disorder?

No, compensatory behaviors are not required.

What is the key diagnostic characteristic of Pica?

• An appetite for substances that are largely non-nurtrative 

  • Ice, hair, drywall etc 

• Persists for more than one month, at an age considered developmentally inappprorpraite 

• Surgery sometimes required to address intestinal obstructions 

What potential complication can arise from Pica?

Intestinal obstructions, sometimes requiring surgery.

What is the key diagnostic characteristic of Rumination disorder?

• A person (usually infant or young child) brings back up and re-chews partially digested food that has already been swallowed 

• In most cases, the re-chewed food is then swallowed again; but occasionally the child will spit it out 

• Treatement sometimes involves diaphagmatic breathing although there is a lack of research 

What is a potential treatment for Rumination Disorder, despite limited research?

Diaphragmatic breathing.

What characterizes Avoidant/Restrictive Food Intake Disorder (ARFID)?

• Significant limitations in food intake leading to malnutrition, weight loss or nutritional deficiency 

• Sensory aversion 

• Occurs without body image disturbances 

• Atypical insula cortex activation associated with aversive responses to certain textures, tastes, or smells of food 

• Prevalent in children with autism 

• Possivbly an early 

What neurological feature is associated with Avoidant/Restrictive Food Intake Disorder?

Atypical insula cortex activation, associated with aversive responses to certain textures, tastes, or smells of food.

In what population is Avoidant/Restrictive Food Intake Disorder (ARFID) more prevalent?

Children with autism.