Anorexia Nervosa Notes

Anorexia Nervosa (AN)

Required Prior Readings

• Rieger (2017) Chapter 9. Eating Disorders.

Overview

• Diagnosis of Anorexia Nervosa
• Epidemiology
• Other Characteristics
• Mortality in Anorexia Nervosa
• Cognitive-Behavioural Conceptualisation of Anorexia Nervosa
• Treatment Outcome

Diagnosis of AN

• Refusal to maintain weight at least 85% of expected weight.
• Intense fear of gaining weight, even when underweight.
• Disturbance in body image perception.
• A criteria of a BMI < 17.5 is often also used as part of a cutoff for Anorexia.
• The presence of amenorrhea (included in DSM-IV) is increasingly recognised as neither useful or relevant in diagnosis of AN (Surgenor et al., 2003)
  (APA, 2013)

Prevalence

• 0.5% lifetime prevalence in females
• 10x more common in females than males
• Onset typically in mid to late adolescence
• Highly variable course and outcome

Body Mass Index (BMI)

• $< 15.0$ Extreme
• $15.0 – 16.0$ Severe
• $16.0 – 17.0$ Moderate
• $> 17.0$ Mild
• $< 17.5$ Extremely Underweight
• $17.5 – 18.5$ Underweight
• $18.5 – 25.0$ Normal
• $25.0 – 30.0$ Overweight
• $> 30.0$ Obese

Common AN Characteristics

• Anorexia Nervosa is often complicated by other traits and psychopathology that complicate the picture.
• Depression and anxiety symptoms
• Obsessional features
• Perfectionism
• Low self-esteem
• Social withdrawal
• Physical complications
• Lack of insight into / acceptance of need for treatment (Wilson & Fairburn, 2002)

Mortality in Anorexia Nervosa

• Crude mortality rates for AN range between 0% and 20%
• More sophisticated analyses of mortality estimate rates of 0.56% per year (Sullivan, 1995)
• Mortality for females age 15-24 = 0.0045% per year
• Mortality for female psychiatric inpatients = 0.021% per year
• Suicide rate in general population = 0.00002% per year
• Predictors of mortality in AN (Keel et al., 2003)
  • Severity of alcohol use and substance use were correlated with mortality
  • A regression model incorporating Duration of Illness, Affective Disorder During Hospitalization, Suicidality, and Severity of Alcohol Abuse was significant in predicting mortality.

CBT Conceptualisation of AN

• Earliest application of Beck’s CT principles to AN in early 1980s (Garner & Bemis, 1982)
• Vitousek (1997)
  • Overvalued ideas about personal implications of body shape and weight originating out of personality variables such as perfectionism, etc.
• Sense of Control (Slade, 1982)
  • Stressed need for control as central feature of AN
  • Success in dieting reinforces sense of control
  • The complex nature of control in AN is elaborated in Surgenor (2002, 2003)

CBT Theory of AN Onset

• Onset of the Disorder
• Need for self-control in context of low-self esteem, perfectionism, and sense of ineffectiveness
• Control over eating is focused on as an experience of success/control
• Dietary restriction provides immediate evidence of self-control
• Control over body shape/weight especially salient to ascetics
• Controlling eating has a strong effect on those in the environment, which may already be clouded with dysfunctional relationships
• Controlling eating provides a mechanism of arresting or reversing pubertal changes
• Western society values dieting to control shape and weight. (Fairburn, Shafran & Cooper, 1999)

CBT Theory of AN Maintenance

• Dietary restriction enhances the sense of being in control
• Amount eaten, types of foods, times of eating
• Success at dietary restriction is a potent reinforcer
• Control over eating as expression of control and worth
• Aspects of starvation encourage further dietary restriction
  • Hunger perceived as threat to control over eating
  • Impaired concentration may heighten sense of chaos/uncontrollability
• Extreme concerns about shape and weight encourage dietary restriction
  • Especially prominent in Western society (Fairburn, Shafran & Cooper, 1999)

The Thin Commandments

• If you aren't thin you aren't attractive.
• Being thin is more important than being healthy.
• You must buy clothes, cut your hair, take laxatives, starve yourself, do anything to make yourself look thinner.
• Thou shall not eat without feeling guilty.
• Thou shall not eat fattening food without punishing oneself afterwards.
• Thou shall count calories and restrict intake accordingly.
• What the scale says is the most important thing.
• Losing weight is good/gaining weight is bad.
• You can never be too thin.
• Being thin and not eating are signs of true will power and success.
• (http://www.proanorexia.ca/thincommandments.html)

Outcome of Treatment of AN

• Steinhausen (2002)
  • Meta-analysis of 119 patient cohorts
  • Total of 5590 patients
  • Variety of different treatment methods.
  • Differences between treatments not assessed
  • Mean dropout rate of 12.3% across all studies. (Steinhausen, 2002)

Predictors of Outcome

• Note that there was considerable heterogeneity among the different studies used in the Steinhausen (2002) meta-analysis.
• Factors unrelated to outcome / with inconsistent findings
  • Weight loss at presentation
  • Hyperactivity
  • Dieting
  • Obsessive Compulsive Disorder
  • Socioeconomic status (Steinhausen, 2002)

Predictors of Outcome

• Predictors of Good Outcome
  • Short duration of symptoms
  • Good parent-child relationship
  • Histrionic Personality features
• Predictors of Poor Outcome
  • Vomiting
  • Bulimia
  • Purgatory behaviour
  • Premorbid developmental abnormalities
  • Eating disorders in childhood
  • Chronicity
  • Obsessive Compulsive Personality Disorder (Steinhausen, 2002)

Summary

• The nature of AN
• Conceptual models of AN
• Cognitions in AN
• Treatment Outcome in AN