Eating Disorders

Eating disorders refer to a group of conditions which are characterised by a disorganised pattern of food consumption which causes physical and emotional distress.

– They are more common in females than males (3:1) with an onset around age 15-30.

– The two most common are anorexia nervosa and bulimia nervosa, which share similar features.

Causes: With most psychiatric conditions, the aetiology can be considered using a biopsychosocial model.

Biological:

Genetics –> Twin studies have shown that eating disorders share a large genetic component

5-HT –> Altered brain serotonin contributes to dysregulation of appetite, mood and impulsivity

Psychological:

Personality –> Higher association with anxious, obsessive-compulsive and depressive traits

Self-esteem –> Higher incidence in people with low self-esteem and altered body image

Social:

Childhood –> Sexual and emotional abuse, overprotective environment, troubled family

Media –> Excessive exposure to media adverts and models encouraging excessive dieting.

Common Symptoms: These can be split into tissue-specific and metabolic:

Tissue:

– Bone –> Osteoporosis

– Muscle –> Breakdown and weakness

– Enlarged salivary glands

– Lanugo hair –> Soft, unpigmented furry hair

– Russell’s sign –> Hand callouses (self-vomiting)

Anorexia Nervosa

This is a disorder characterised by restrictive eating, which is due to a morbid fear of fatness.

– Patients lose weight either by dieting, purging (vomiting), laxative/diuretic abuse.

Diagnosis: 3 key features

i) Low body weight (<85% body mass)

ii) Distorted body image

iii) Morbid fear of fatness

– Amenorrhoea 3 consecutive cycles

– Loss of sexual interest in men

Management:

Acute – Nasogastric feeding tube if:

– BMI <13, bradycardic, K⁺ <3mM or clearly dehydrated

Chronic – Referral for specialist care

– Children – 1st line is Anorexia-focussed family therapy, 2nd line is CBT

– Adults – 1st line is eating-disorder focussed CBT or Specialist supportive clinical management (SSCM)

Prognosis: 40% recover but 10% mortality risk

Bulimia Nervosa

This is characterised by episodes of binge eating followed by intentional purgative behaviours in order to lose weight.

– This can include intentional vomiting or other behaviours like laxative/diuretic abuse or excessive exercise.

Diagnosis: 5 Key features (Weight is typically normal)

i) Preoccupation with body shape and weight

ii) Recurrent binge eating (an amount that is clearly more than people would eat and with a clear loss of control)

iii) Inappropriate compensatory behaviours to stop weight gain

iv) Occur once/week for at least 3 months

v) Episodes not occurring during episode of Anorexia nervosa

Management:

Acute – Nasogastric feeding tube if:

– BMI <13, bradycardic, K⁺ <3mM or clearly dehydrated

Chronic – Referral for specialist care

– Children – 1st line is Bulimia-focussed family therapy, 2nd line is CBT

– Adults – 1st line eating-disorder focussed CBT (CBT-ED) or Interpersonal therapy (IPT)

– Fluoxetine is licensed in bulimia only, not anorexia

Prognosis: With CBT, 30-40% of patients manage to achieve remission, much lower mortality risk than anorexia

Binge Eating Disorder

This is an eating disorder characterised by recurrent episodes of binge-eating without the purging behaviours.

Symptoms

– Characteristed by binge eating behaviour – Eating much more than normal and with a clear loss of control

– Binge eating still gives emotional distress and anxiety and typically co-occurs with obesity (BMI >30)

Management:

1st line is guided self-help –> 2nd line is group CBT –> 3rd line is individual CBT