• Became a distinct category in DMS-IV, DSM-5: eating disorders found in “Feeding & Eating Disorders” chapter o Pica = eating nonfood substances for extended periods o Rumination = repeated regurgitation of foods

Clinical Descriptions of Eating Disorders I. Anorexia Nervosa (AN) DMS-5 Criteria:

1) Restriction of food that leads to very low body weight; body weight is significantly below normal

BMI less than 18.5) o Weight loss achieved through dieting and perhaps purging and excessive exercise

2) Intense fear of weight gain/being fat or repeated behaviours that interfere with weight gain *fear not reduced by weight loss

3) Body image disturbance *distorted body image or sense of body shape o Particularly the abdomen, hips, thighs are too fat

    • Weight themselves frequently, measure themselves, gaze in the mirror critically o Often assessed via questionnaire
    • Women ideal: very thin (compared to normal), overestimate their own size, Male ideal: same as normal, overestimate their own size
  • SEVERITY: (BMI) Mild = =/< 17, Moderate = 16-16.99, Severe = 15-15.99, Extreme = <15 o Healthy BMI is between 20-25
  • Amenorrhea = loss of menstrual period, is no longer a criteria
  • Term anorexia refers to loss of appetite, nervosa indicates loss is due to emotional reasons

 2 subtypes:

o   1) Restricting type: weight loss is achieved by severely restricting food intake

    • 2) Binge eating/purging: person has also regularly engaged in binge eating and purging
      • Nearly 2/3 who meet category 1, switched over to 2 eight years later
    • Typically begins in middle teenage years, often after episode of dieting an occurrence of life stress
    • Prevalence: less than 1% (stable), 10x as frequent in women as men *greater cultural emphasis on women’s beauty o Higher mortality from men with disorder than women
    • Comorbid with: depression, OCD, specific phobia, panic disorder and personality disorders  High suicide rates: 5% complete, 20% attempt Physical Consequences
    • Low blood pressure, slow heart rate, kidney/gastrointestinal problems, bone mass declines, skin dries, brittle nails, mild anemia
    • Lanugo = fine, soft hair, loss of hair from scalp
    • Loss of Na and K electrolytes  tiredness, weakness, cardiac arrhythmias, sudden death

Prognosis

  • 50-70% eventually recover, often after 6-7 years, common relapses before
  • Death rates are 10x higher than the general population, 2x as high as those with other psyc disorders
  • 3-5% mortality rates among women *most often from physical complications (heart failure) and suicide o Death most likely among those who have had it for the longest Bulimia Nervosa (BN)

DSM-5 Criteria

  • 1) Recurrent episodes of binge eating o Eating an excessive amount of food within a short period of time
    • Accompanied by feeling of losing control over eating – feel like one cannot stop
  • 2) Recurrent compensatory behaviour to prevent weight gain, for example, vomiting
  • 3) Body shape and weight are extremely important for self-evaluation

 

 

Bulimia comes from a Greek word for ox hunger – rapid consumption of a large amount of food

  • People with bulimia are distinct from anorexia because they do not lose an excessive amount of weight
  • Binges occur in secret, triggered by stress and negative emotions they arouse, continue until uncomfortably full o Often involves soft, sweet foods that can be rapidly consumed: ice cream, cake o More likely to binge while alone, during morning/afternoon o Avoiding a craved food can lead to a binge the next day o Likely to occur after negative social interaction
  • Severity: (Compensatory behaviours) Mild = 1-3/week, Moderate = 4-7/week, Severe = 8-13/week, Extreme = 14+/week
  • Must occur at least once a week for 3 months
  • Self-esteem depends heavily on maintaining normal weight
  • More accurate than normal population in reporting height/weight
  • DSM-IV-TR included subtypes which were removed
  • Begins in late adolescence/early adulthood, 90% are women, 1-2% prevalence among females
  • Many are somewhat overweight before onset
  • Comorbid with: depression, personality disorders, anxiety disorders, substance use disorders, conduct disorder o Increase likelihood in both directions, except bulimia usually precedes substance use disorders
  • Higher suicide rates than normal population (lower than anorexia)

Physical Consequences

  • Typically have a normal BMI but amenorrhea can still occur
  • Frequent purging can lead to K depletion, loss of electrolytes, irregular heartbeat
  • Vomiting can lead to tearing of stomach tissue and throat tissue, loss of dental enamel  Swollen salivary glands
  • Mortality rate of 4% for women

Prognosis

  • Close to75% recover, 10-20% remain fully symptomatic
  • Earlier intervention linked to better prognosis Binge Eating Disorder (BED) DSM-5 Criteria:
  • 1) Recurrent binge eating episodes o 1+/week for 3 months
  • 2) Binge eating episodes include at least 3 of the following:
    • Eating more quickly than usual, eating until over full, eating large amounts even if not hungry, eating alone due to embarrassment about large food quantity, feeling bad after binge
  • 3) No compensatory behaviour is present
  • Most often are obese (BMI greater than 30), prevalence among 2-25% of obese people o Many have a history of dieting
  • Severity (# binges/week): Mild 1-3/week, Moderate = 4-7/week, Severe = 8-13, Extreme = 14+/week
  • Comorbid with: mood disorders, anxiety disorders, ADHD, conduct disorder, substance use disorder
  • Risk factors: childhood obesity, critical comments about being overweight, weight-loss attempts in childhood, low self-concept, depression, and childhood abuse
  • More prevalent than other eating disorders, 0.2-4.7% prevalence, more common in women (less gender difference)
  • Equally prevalent cross-culturally

Physical Consequences

  • Increased risk of type II diabetes, cardiovascular problems, chronic back pain, headaches  Sleep problems, anxiety, depression, IBS, early onset menstruation for women

Prognosis

  • 25-82% of people recover
  • Lasts approximately 14.4 years (longer than anorexia/bulimia) or just over 4 years? Etiology of Eating Disorders

Genetic Factors

  • Unlikely caused by 1 gene, although they do run in the family
  • 1st degree relatives of women with anorexia are 10x more likely to have the disorder, 4x for bulimia o Same for men with anorexia, but not bulimia
  • Higher MZ than DZ concordance rates for anorexia and bulimia
  • Environmental factors are also very important (higher proportion of bulimia due to environmental than genetic factors)
  • Heritable: dissatisfaction with one’s body, strong desire to be thin, binge eating, preoccupation with weight
  • Genetic factors may link to negative emotionality and constraint with eating disorders

Neurobiological Factors

  • Hypothalamus is a key brain structure involved in regulating hunger *not dysfunctional in anorexia
  • Endogenous opioids reduce pain sensations, enhance mood and suppress appetite o Released during starvation, related to anorexia, bulimia and BED **increased levels o Excessive exercise increases opioids *reinforcing
  • Low levels of beta-endorphin in bulimia *not sure if this is a cause or effect
  • Serotonin – related to eating and satiety (feeling full) *promotes satiety o Binges could result from serotonin deficit o Food restriction interferes with serotonin synthesis
    • Low levels of serotonin metabolites in AN and BN = underactive NTM activity o Show poor response to 5-HT agonists in AN if haven’t been restored to healthy weight o Linked to comorbid depression
  • Dopamine – related to reward/pleasure aspects of food o Linked to motivation to obtain food o Restrained eaters more sensitive to food cues o Ventral striatum linked to DA level and reward

 More activated in people with AN when looking at images of thin women o People with AN or BN show greater expression of DA transported gene DAT o Bingeing on sucrose leads to increased release of DA in the striatum

Cognitive-Behavioural Factors

  • Focus on distorted body image, fear of fat, loss of control of over eating  Anorexia Nervosa:
    • Emphasis on fear of fatness and body image disturbance as motivating factor that reinforced weight loss
    • Onset often follows a period of weight loss and dieting
    • Behaviours to achieve thinness are negatively reinforced by reduction of anxiety about becoming fat
      • Positively reinforced by comments form others o Dieting and weight loss positively reinforced by sense of mastery or self-control o Perfectionism and sense of personal inadequacy may lead a person to become concerned with appearance
      • Compare oneself to portrayals in media of thin ideal, being overweight and comparing to attractive others all lead to greater dissatisfaction in one’s body image
    • Criticism from peers and parents about being overweight
    • Experience many negative emotions but also positive emotions (e.g. pride) after losing weight or avoiding treats
      • Low positive emotion differentiation: may confuse this feeling with happiness or success
      • Low positive emotion differentiation predicts eating disorder behaviours (same with high negative)  Bulimia Nervosa and BED:
    • View self-worth in terms of body weight and shape
    • Low self-esteem, hope control over body will help feel better generally o Try to follow strict eating plan, rules are inevitably broken, escalates into binge o Feelings of disgust and fear build up after binge, leading to compensatory actions o Purging temporarily reduces anxiety but lowers self-esteem, and cycle repeats
      • Low SE and high negative affect  Dieting to feel better about self  Food intake restricted too severely  Diet is broken  Binge  Compensatory behaviours to reduce fear of weight gain
    • Restraint scale – questionnaire measure of concerns about dieting and overeating o Bingeing helps regulate amount of negative affect, although tend to experience more negative affect after binge
    • Purging is reinforced by decreasing negative affect
    • Concerns about body shape and weight predict restrained eating, which predicts increased bingeing
    • Attention, memory and problem solving are affected with eating disorders
      • Attention focused on food-related images/words longer
      • Remember food words more when full w/AN

Sociocultural Factors

  • BMI of ideal female models has decreased over time, male BMI increased due to increased muscularity
  • As cultural standards moved more towards thin ideal, more and more people were becoming overweight
  • Over 2/3 of Americans are overweight
  • Dieting has become more common (29% of men and 44% of women diet)
  • A 1/3 of women 25-45 report spending over half their lifetime trying to lose weight
  • Diets are equally effective whether fats, carbs, or proteins are cut as long as number of calories are reduced
  • Women are more likely to diet than men
  • Highest risk for developing eating disorders with high BMI and body dissatisfaction
  • Sociocultural ideal of thinness leads to people learning to fear being/feeling fat
  • “Pro-eating disorder” websites – women who visit these sites are more dissatisfied with their bodies, have more eating disorder symptoms and more likely experienced hospitalizations for eating disorders o Viewing these websites has potential to cause unhealthful changes in eating behaviours  Gender Influence:
    • More common in women than men
    • Western culture emphasizes thin ideal more in women
    • Highest among groups expected to be concerned with thinness/weight: gymnasts, models, dancers
    • Objectification of women’s bodies – women are defined by their bodies, men are esteemed for their accomplishments
    • Objectification theory = prevalence of objectification message has led some women to selfobjectify *see their own body through the eyes of others
      • Causes women to feel more shame about their bodies o As women get older, become less concerned with body weight, diet less (even though they tend to weight more then)
      • Changes in life roles: having a life partner, having a child associated with decreased eating disorder symptoms
      • Men more concerned about body image, increased dieting  Cross-Cultural Studies:
    • AN observed in a number of cultures/countries with very little Western cultural influence
      • Doesn’t include same degree of fear of gaining weight as it does in Western culture o In other cultures higher weight has greater value, better potential for fertility and happiness o BN more common among industrialized nations
    • Ethnic Differences:
      • Greater incidence among white than black women *most pronounced among college students
      • White/Hispanic report greater body dissatisfaction than African American o Acculturation can be stressful
        • High levels of acculturation stress in African American and Hispanic related to greater body dissatisfaction and bulimia symptoms
      • Found among all levels of SES

Other Contributing Factors

  • Personality Factors:
    • Personality in those with AN is affected by weight loss
    • Become preoccupied with food, increased fatigue, poor concentration, lack of sexual interest, irritability, moodiness, insomnia
    • Before onset of AN: perfectionistic, shy, compliant
    • BN: adds, histrionic features, affective instability, outgoing social description
    • Poor interoceptive awareness = extent to which people can distinguish between different biological states of their bodies
    • Propensity to experience negative emotions
    • Perfectionism is multifaceted and may be self-oriented (setting high standards for self), otheroriented or socially oriented (trying to conform to high standards imposed by others
      • Remains high even after successful treatment
      • Mothers of girls with AN score higher on perfectionism  Characteristics of Families: o Self-reports reveal high level of family conflict, parental reports do not agree
    • Parents of child with eating disorders do not seem to differ from parents of those without in frequency of positive and negative messages
      • Parents of children with eating disorders more self-disclosing
      • Lack some communication skills

 

Child Abuse and Eating Disorders:

  • Higher self-reports of sexual abuse among those with eating disorders, especially BN

Treatment of Eating Disorders

  • Hospitalization is frequently required for AN to increase food ingestion and carefully monitor  IV feeding might be necessary to save life Medications
  • BN comorbid with depression, treated with various antidepressants, reduces purging and binge eating
  • Many people don’t maintain medication treatment
  • Many relapse after medication is withdrawn (less so alongside CBT)
  • Medication also used to treat AN, anti-obesity drugs show some promise with BED

Psyc Treatment of AN

  • 2 tiered process:
    • 1) Immediate goal is to help person gain weight to avoid medical complications/possibility of death
      • Use operant conditioning behaviour therapy: provide reinforcers for gaining weight

*affective short term

2) Long-term maintenance of weight gain *challenge

  • CBT – effective after hospitalization to reduce risk of relapse
  • CBT and psychotherapy + education are equally effective in reducing eating disorder symptoms and depression
  • Older women with more severe symptoms benefit most from CBT
  • Family therapy – interactions among members of patient’s family can play a role in treating the disorder o Higher rates of remission compared to individual therapy
  • Early weight gain is an important predictor of a good outcome

Psyc Treatment of BN

  • CBT is standard treatment o Question society’s standards for physical attractiveness
    • Uncover and change beliefs that encourage starvation in order to avoid becoming overweight o Normal body weight can be maintained without severe dieting o Unrealistic restriction of food intake can trigger a binge
    • All is not lost with one bite of high calorie food, snacking need not trigger a binge o *Alter the all-or-nothing thinking
  • Goal to develop more typical eating patterns: 3 meals a day with some snacks
  • CBT therapist challenges unrealistic beliefs about ties between weight gain and self-worth
  • Challenge cognitive distortions: e.g. that eating a small amount of high-calorie food = utter failure
  • Reductions in bingeing/purging in 70-90% of patients with CBT
  • CBT more effective than drug treatment
  • ERP (exposure & response prevention) – discouraging person form purging *more effective in addition to CBT in short term
  • Guided self-help – receive self-help books on topics such as: perfectionism, body image, negative thinking, food & health o Greater confidence in one’s ability to change is related to better outcomes
  • Interpersonal therapy (IPT) – did not produce results as quickly as CBT
  • Family therapy – superior to supportive psychotherapy Psyc Treatment of BED
  • CBT shown to be effective
  • Targets binges and restrained eating by emphasizing self-monitoring, self-control, and problem solving with eating
  • Gains last up to 1 year after treatment
  • IPT is as effectives as CBT and guided self-help for BED
  • Having a therapist lead CBT may help keep people in treatment and reduce binges

Preventive Interventions for Eating Disorders

  • Intervene with children/adolescents before onset

1) Psycho-educational approaches – educate children/adolescents about eating disorders in order to prevent them from developing symptoms

2) Deemphasizing sociocultural influence – helping children and adolescents resist/reject sociocultural pressures to be thin

3) Risk factor approach – identifying people with known risk factors and intervening to alter these factors

  • Most effective: interactive, include teens 15+ years-old, girls only, multiple sessions
  • Body project – dissonance reduction intervention focused on deemphasizing sociocultural influences  Healthy weight intervention – targets risk factors