Chapter 12: Bulimia Nervosa and Binge Eating Disorder

1. Chapter 12: Bulimia Nervosa and Binge Eating Disorder Linda W. Craighead Margaret A. Martinez Kelly L. Klump

2. DSM-5 Changes for Eating Disorders DSM-IV-TR: Eating Disorders (EDs): • Anorexia Nervosa (AN) • Bulimia Nervosa (BN) • Eating Disorder Not Otherwise Specified (EDNOS) • Separate Chapter had Disorders Usually First Diagnosed During Infancy, Childhood, or Adolescence DSM-5: Feeding and Eating Disorders (FED): • Anorexia Nervosa (AN) • Bulimia Nervosa (BN) • Binge Eating Disorder (BED); in DSM-IV-TR appendix as provisional • Other specified FED • Unspecified FED - Avoidant/restrictive food intake disorder - Pica - Rumination Disorder

3. Rationale for Changes • Changes intended to: • Reduce the frequency of the unspecified diagnosis • Establish criteria appropriate for clinical presentations at younger ages • There is some concern that the new criteria may dramatically increase the number of individuals diagnosed with an eating disorder

4. DSM-5 Diagnostic Criteria for BN BULIMIA NERVOSA • Recurrent episodes of binge eating. Binge eating characterized by BOTH: • Eating an objectively large amount of food, i.e. larger than most people would eat in a similar period of time and under similar circumstances; • A sense of loss of control over eating during the episode. B. Recurrent inappropriate compensatory behavior in order to prevent weight gain (e.g. self-induced vomiting, misuse of laxatives/diuretics/enemas/other medications) C. Binge eating and inappropriate compensatory behaviors both occur, on average, at least once a week for three months D. Self-evaluation is unduly influenced by body shape and weight. E. The disturbance does not occur exclusively during episodes of Anorexia Nervosa Indicates change from DSM-IV-TR criteria

5. Objective Binge Episode • To be classified as an objective binge episode (OBE), individual must: • Consume an objectively large amount of food, that is more than most people would eat in a similar situation and in a discrete period of time (e.g., 2 hours) • Objectively large ≈ 3x the typical portion for that food • 1,900 calories on average (Bartholome, Raymond, Lee, Peterson, & Warren, 2006) • Experience a subjective feeling of loss of control over eating

6. Subjective Binge Episode • Subjective binge episode (SBE): • Individual experiences loss of control while eating an amount of food considered normal or small • For example, one bowl of ice cream (SBE) versus a gallon of ice cream (OBE) • 700 calories on average (Bartholome, Raymond, Lee, Peterson, & Warren, 2006) • Only OBEs count toward frequency criterion for diagnosis of BN/BED

7. Characteristics of a Binge • Typically occur when individual is alone • May be comprised of high-calorie foods (i.e., ice cream) or healthy foods (i.e., carrots) • Restricted intake before and after binge episode • Can be spontaneous or planned • Triggered by negative/positive emotions, interpersonal stressors, presence of tempting food, violation of a dieting rule, body image dissatisfaction, excessive hunger, and so on

8. Obstacles to Treatment in BN • Bulimia is often not detected until later in the course of illness, often because: • Binge/purge episodes feel habitual and are perceived as problematic • Function of binge episodes as distracting from negative emotions • Conviction that stopping purging behaviors will lead to weight gain • Shame and embarrassment associated with binge/purge behaviors

9. Medical Complications of BN • Medical complications typically associated with purging • Complications include: • Electrolyte abnormalities • Esophageal/gastrointestinal symptoms • Menstrual irregularities • Thyroid dysfunction • Dental problems • Enlarged parotid glands • Decreased stomach motility

10. Proposed DSM-5Diagnostic Criteria BINGE EATING DISORDER • Recurrent episodes of binge eating. Binge eating characterized by both: • Eating an objectively large amount of food, that is an amount larger than most people would eat in a similar period of time and under similar circumstances • A sense of loss of control over eating during the episode • Binge eating episodes are associated with at least three of the following: • Eating more rapidly than normal; • Eating until uncomfortably full; • Eating large amounts of food when not feeling physically hungry • Eating alone because of being embarrassed by how much one is eating • Feeling disgusted with oneself, depressed, or very guilty after overeating • Marked distress regarding binge eating is present • Binge eating occurs, on average, at least oncea week for 3months E. The disturbance does not occur exclusively during episodes of anorexia nervosa and is not accompanied by inappropriate compensatory behaviors, as in bulimia nervosa. **Indicates change from provisional DSM-IV-TR criteria

11. Distinction Between BN and BED • Both BN and BED require the presence of objectively large binge episodes (at least 1x/week for 3 months) in individuals who are not significantly underweight • In BED, no inappropriate compensatory behaviors • BED does not require concern about shape/weight, although this is often reported • Both BN and BED can be chronic conditions exacerbated by life stressors

12. Medical complications of BED • Medical complications less common in BED • Most common complaint is gastrointestinal distress associated with binge episodes • Individuals with BED are more often affected by complications of comorbid obesity • Many (but not all) individuals with BED are also overweight/obese • Those individuals with BED who are not overweight are at risk of developing obesity

13. History of Binge Eating

14. Transdiagnostic Model of Eating Disorders • Proposed by Fairburn et al., a diagnostic approach that focuses on the similarities between various types of eating disorders • Views overevaluation of eating, shape, and weight as the core pathology underlying all eating disorders • Hypothesizes that overevaluation leads to restriction/dieting that, in turn, leads to disordered eating • May explain the high rate of diagnostic crossover in eating disorders • Limitations of the transdiagnostic model: • Many individuals with BED report onset of binge eating before development of weight concerns

15. Epidemiology • Using DSM-IV criteria, prevalence of BN is ~0.5% to1.0% • Prevalence of any binge eating symptoms is 5.7% • Using DSM-5 criteria, prevalence of BN is ~2% • ~90% of those diagnosed are women • Using DSM-IV criteria, prevalence of BED is ~2% to 5% • Prevalence among individuals seeking weight-loss interventions is higher, ~30% • Using DSM-5 criteria, prevalence of BED is ~3.6% in women and 2.1% in men • More equitable gender distribution (~65% female, 35% male) • Binge eating may be more common among certain minority groups

16. Course • Typical age of onset for BN is late adolescence/early adulthood • Individuals with BN often have a history of AN (~10% to 14% of community samples, ~25% to 37% of clinical samples) • Onset of OBEs may be earlier than the age at which the individual meets full diagnostic criteria for BN or BED • Both BN and BED have a chronic course and high relapse rates

17. Comorbidity • Common Axis I cormorbidities include: • Mood disorders • Especially major depression and dysthymia • Anxiety disorders • Posttraumatic stress disorder is more common in BN and BED than AN • Substance abuse • Common Axis II comorbidities include: • Borderline personality disorder • Avoidant, dependent, histrionic, and paranoid personality disorders

18. Genetic Risk Factors • AN, BN, and BED have moderate-to-large heritabilities, similar to biologically based illnesses • In girls, genetic risk activated during puberty • In boys, genetic risk remains constant across the lifespan • Estrogen may account for difference in pubertal risk • Some genes have been implicated, including serotonin, neurotrophic, estrogen receptor, and dopamine genes • Dieting and other environmental factors may increase genetic risk

19. Neurobiological Risk Factors • Overactivity in opioid and dopaminergic systems in binge eating resembles that seen in substance use • Neural patterns may vary over course of illness • Hypothesized that overactive reward networks may increase risk for developing binge eating… • …once binge eating develops, binge behaviors may result in down-regulation and hyposensitivity of neural reward pathways

20. Personality Traits • Impulsivity • Impulsivity associated with binging and purging • Impulsivity abates with recovery • Obsessionality • Individuals with eating disorders tend to have obsessive-compulsive traits • Perfectionism • May mediate the relationship between eating disorders and obsessive-compulsive symptoms

21. Emotion Dysregulation • Binge eating conceptualized as emotion regulation strategy • Negative affect precedes and maintains onset of binge eating • Negative affect also associated with body dissatisfaction and dieting behaviors, which may compound the relationship between negative affect and binge eating • Although binge eating may momentarily reduce negative affect, episode is often followed by increased negative affect • Compensatory behaviors may reduce negative affect and thus increase as a result of negative reinforcement

22. Cognitive Dysfunction • Cognitive symptoms of BN include: • Appearance overvaluation • Self-worth is disproportionately affected by body shape and weight • Internalization of the thin ideal • Thin cultural standard is fully adopted • Cognitive biases • Attention and memory biased towards information regarding food, weight, and shape • Rigid and obsessive thinking patterns • Thinking characterized by strict and dichotomous patterns

23. Risk Factors • Body dissatisfaction • Leads to negative affect and dieting behavior, which in turn may produce disordered eating • Dieting • Excessive caloric deprivation may trigger binge eating • Interoceptive awareness • Deficits in ability to monitor internal states predicts onset of eating disorder symptoms • Body mass • Higher body mass may contribute to disordered eating through increased body dissatisfaction and dieting behaviors

24. Environmental Factors • Sociocultural pressure • No clear causal relationship between media exposure and onset of eating disorders • Family • Family attitudes and behavior may contribute to thin ideal internalization and the failure to develop effective coping strategies • Childhood sexual abuse • History of abuse is a risk factor for general psychopathology, not specific to eating disorders

25. Assessment • Interview measure of eating disorder symptoms • Eating Disorder Examination (EDE): Assesses disordered attitudes and behaviors over past 4 weeks • Four subscales assess restraint, concern about eating, concern about shape, and concern about weight • Structured format ensures assessment of a variety of constructs are assessed • Takes time to complete interview and the extensive training required to use it limits use in clinical settings

26. Assessment, cont • Self-report measures of eating disorder symptoms • Questionnaire version of EDE (EDE-Q) • Can be used for diagnostic purposes or to assess dimensions of eating pathology • Eating Disorder Inventory (EDI) and Bulimia Test–Revised (BULIT-R) • Global measures with multiple subscales, often used to assess treatment outcome • Children’s Eating Attitudes Test (Ch-EAT) • Used to assess eating disorders in children

27. Treatment of BN • Psychological interventions • Clinical trials have established Cognitive Behavioral Therapy (CBT) and Interpersonal Therapy (IPT) as optimal treatments • Although CBT may initially be more effective, individuals receiving IPT continue to show improvement over follow-up so no difference in long run • Interventions may be delivered in guided self-help format to increase treatment access • Pharmacological interventions • Antidepressant medications to prevent relapse when medication stopped effective but best to use in combination with CBT • Further research required to determine best treatments for males, older women, and adolescents

28. Treatment of BED • Psychological interventions • As with BN, CBT and IPT are effective treatments • Self-help treatments also effective • Behavioral Weight Loss (BWL) often used to treat comorbid obesity, but weight loss is minimal • Pharmacological interventions • Fluoxetine may reduce binge episodes in BED, as in BN, but does not contribute to weight loss • Topirimate thought to control impulsive tendencies • Medications do not seem to confer additional benefit beyond psychotherapy

29. Prevention of Eating Disorders • Programs targeting high-risk individuals more effective than those implemented universally • Prevention programs generally effective in raising awareness of eating disordered symptoms, less effective in reducing risk factors • Novel programs capitalize on cognitive dissonance by asking participants to critique the thin ideal