Bulimia Nervosa

Question 1

Essence

Answer 1

Characterised by recurrent episodes of binge eating, with compensatory behaviours and overvalued ideas about ‘ideal’ body shape and weight

Question 2

Epidemiology - incidence

Answer 2

1-1.5% of woman

Question 3

Epidemiology - onset and presentation

Answer 3

Mid-adolescent onset and presentation in early 20s

Question 4

Aetiology

Answer 4

• Similar to anorexia
• But evidence for associated personal/family history of obesity, affective disorder and/or substance abuse
• Possible dysregulation of eating related to serotonergic mechanism (?supersensitivity of 5-HT_2C secondary to decreased 5-HT)

Question 5

Diagnostic criteria

Answer 5

• Persistent preoccupation with eating
• Irresistible craving for food
• Binges - episodes of overeating
• Attempts to counter fattening effects of food
  
  • Self-induced vomiting, abuse of purgatives, periods of starvation, use of drugs
• Morbid dread of fatness with imposed low weight threshold

Atypical cases may not include one or more feature

Question 6

Methods of purging

Answer 6

• Self-induced vomiting
• Abuse of purgatives
• Periods of starvation
• Use of drugs

Question 7

Drugs for purging

Answer 7

• Laxatives
• Appetite suppresants
• Thyroxine
• Diuretics

Question 8

Physical signs

Answer 8

• May be similar to anorexia but less severe
• Specific problems related to purging
  
  • Arrhythmias
  • Cardiac failure (sudden death)
  • Electrolyte disturbances
  • Oesophageal erosions
  • Gastric/duodenal ulcers
  • Pancreatitis
  • Constipation/steatorrhoea
  • Dental erosion
  • Leukopenia/lymphocytosis

Question 9

Electrolyte imbalances

Answer 9

• Decreased K
• Decreased Na
• Decreased Cl
• Metabolic acidosis (laxatives) or alkalosis (vomiting)

Question 10

Investigations

Answer 10

• As for anorexia
  
  • BMI
  • Assess physical sign of starvation and vomiting
  • Routine and focussed blood tests
  • ECG (and echocardiogram if indicated)

Question 11

Differential diagnosis

Answer 11

• Upper GI disorders (with associated vomiting)
• Brain tumours
• Personality disorder
• Depressive disorder
• OCD
• Drug related increased appetite
• Other causes of recurrent eating
  
  • Such as menstrual syndrome or Kleine-Levin syndrome

Question 12

Comorbidity

Answer 12

• Anxiety/mood disorder
• Multiple dyscontrol behaviours such as
  
  • Cutting/burning
  • Overdose
  • Alcohol/drug misuse
  • Promiscuity
  • Other impulse disorders

Question 13

Treatment

Answer 13

• General principles
  
  • Full assessment
  • Usually managed as outpatient
  • Admission only for suicidality, physical problems, extreme refractory cases or if pregnant
• Pharmacological
  
  • High dose SSRIs (fluoxetine 60mg) with long term treatment (>1 year)
• Psychotherapy
  
  • CBT
  • Guided self-help with educational support useful first step

Question 14

Prognosis

Answer 14

Good unless significant issues of low self-esteem or evidence of severe personality disorder