Eating disorders

Question 1

What is the prevalence of eating disorders in males vs females?

Answer 1

They are 10 times more common in females

Question 2

What is the incidence of anorexia in the UK?

Answer 2

1%

Question 3

Which has a higher incidence: anorexia or bulimia?

Answer 3

The exact incidence of bulimia is difficult to know because many sufferers never present. However, it is estimated that the incidence of bulimia is approximately 5 times higher than that of anorexia.

Question 4

Are eating disorders associated with a particular social class?

Answer 4

Classically, anorexia was considered to be more prevalent in higher socioeconomic classes, however, recently this seems to have changed and prevalence is pretty equal across all classes. Bulimia also has equal prevalence across all socioeconomic classes.

Question 5

What are the biological factors that may provide a cause for someone developing anorexia?

Answer 5

Genetics play a big part - MZ twins (55%) DZ twins (5%)

Abnormalities of serotonin metabolism

Question 6

What are the environmental and psychological factors that may provide a cause for developing anorexia?

Answer 6

Western culture - ideal body image
Relationship difficulties - both parental (overprotection, conflict avoidance, enmeshment) and peer to peer (boyfriend splitting up with patient)
Exam stress

Question 7

What are the personality traits that increase someone’s chance of developing anorexia?

Answer 7

Inhibition
Perfectionism
Obsessionality
Harm avoidance

Question 8

What are the biological factors that may provide a cause for someone developing bulimia?

Answer 8

Genetic component is a big part
Serotonin, noradrenaline and plasma endorphins have all been implicated (however, these could be secondary to weight loss)
Family history of depression
Early menarche

Question 9

What are the environmental and psychological factors that may provide a cause for developing bulimia?

Answer 9

Past exposure to dieting
History of childhood obesity
Conflictual relationships with family
Alcohol and substance misuse
Personality disorders
Depression

Question 10

What is the cut-off BMI for anorexia in adults?

Answer 10

A BMI of less than 17.5 kg/m2 is characterised as anorexia.

Question 11

How do you calculate a person’s BMI?

Answer 11

Weight (kg) / height (m) x height (m)

Question 12

What are the ICD-10 criteria for anorexia nervosa?

Answer 12

All of the following:

1. Low body weight: 15% below expected (BMI of less than 17.5 kg/m2 in adults)
2. Self-induced weight loss (poor calorie intake, vomiting, exercise, etc.)
3. Overvalued idea: dread of fatness, self-perception of being too fat; low target weight
4. Endocrine disturbance: hypothalamic-pituitary-gonadal axis, resulting in amenorrhea, raised cortisol, growth hormone

Question 13

What are the ICD-10 criteria for bulimia nervosa?

Answer 13

All of the following:

1. Binge eating
2. Strong cravings for food
3. Methods to counteract weight gain (vomiting, laxatives, fasting, exercise, etc)
4. Overvalued idea: dread of fatness, self-perception of being too fat; low target weight

Question 14

If an anorexic patient begins to binge eat and purge, are they now classified as bulimic?

Answer 14

No. The key diagnostic difference is the weight and the significant generalised endocrine abnormalities. By the DSM-V they would now be classified as ‘anorexia nervosa, binge eating/purging type’.

Question 15

What other psychiatric symptoms other than those specifically related to eating, might someone with an eating disorder report?

Answer 15

Anxiety

Depression

Question 16

What are the physical complications of starvation in a patient with an eating disorder?

Answer 16

MUSCLES & BONES:
• Emaciation (wasting of flesh)
• Proximal myopathy; muscle wasting
• Lanugo (fine, downy hair on trunk); loss of head hair - due to being cold
• Osteoporosis; fractures
REPRODUCTIVE SYSTEM:
• Amenorrhea; infertility; reproductive system atrophy
CARDIO:
• Cardiomyopathy
• Bradycardia; hypotension; cardiac arrythmias; heart failure
• Peripheral oedema
GI:
• Constipation; abdominal pain
• Cold intolerance; lethargy
NEURO
• Seizures; impaired concentration; depression

Question 17

What are the physical complications of purging (vomiting) in a patient with an eating disorder?

Answer 17

• Permanent erosion of dental enamel; dental cavities
• Enlargement of salivary glands (especially parotid)
• Russell’s sign - calluses on back of hands from repeated trauma from teeth during induction of vomiting.
• Oesophageal tears; gastric rupture

Question 18

What might the blood tests of an eating disorder patient show as a result of their starvation?

Answer 18

• Normocytic anaemia
• Leucopenia
• Abnormal LFTs
• Raised urea
• Raised cortisol
• Raised growth hormone
• Reduced T3
• Reduced FSH and LH
• Hypercholesterolaemia
• Hypoglycaemia
• Hypercarotenaemia

Question 19

What might the blood tests of an eating disorder patient show as a result of their purging (vomiting)?

Answer 19

• Hypokalaemia
• Hypochloraemia
• Alkalosis
• Hyponatraemia
• Hypomagnesaemia
• Raised serum amylase

Question 20

Other than blood tests, what investigations might you order for someone who presents with the symptoms and signs of an eating disorder?

Answer 20

ECG

Echo

Bone density scan

Question 21

What should form the rest of your differential diagnosis for anyone that comes in with a low BMI or a history of rapid weight loss, in whom you suspect may have an eating disorder?

Answer 21

Malignancies

Gastrointestinal disease

Endocrine disease (eg hyperthyroidism, diabetes mellitus)

Chronic infections

Chronic inflammatory conditions

Question 22

Other than eating disorders, what psychiatric disorders might lead to a patient losing weight?

Answer 22

Depression

Obsessive compulsive disorder

Psychotic disorders

Alcohol or substance abuse

Dementia

Question 23

When should hospitalisation be considered for a patient with an eating disorder?

Answer 23

Body mass index of 13.5 or less

Rapid weight loss

Severe electrolyte abnormalities

Syncope

Risk of suicide

Social crisis

Question 24

Can a patient be force-fed under the mental health act?

Answer 24

While the mental health act only makes provision for the compulsory treatment of mental illness (not physical illness), food is considered to be treatment for mental illness because it leads to improvement in psychological symptoms caused by starvation.

Question 25

What is re-feeding syndrome?

Answer 25

A severe disturbance in electrolyte levels as a result of eating after a prolonged period of starvation. This is mostly caused by the release of insulin, which induces cellular uptake of phosphate, magnesium and potassium.

Electrolyte imbalances include:
Hypophophataemia
Hypokalaemia
Hypomagnesaemia 
Hyponatraemia 
Metabolic acidosis
Thiamine deficiency

The complications include: 
Muscle weakness
Seizures
Peripheral oedema
Cardiac dysrythmias
Hypotension
Delirium

Question 26

What are the poor prognostic factors of anorexia nervosa?

Answer 26

Long duration

Late age of onset

Very low weight

Associated binge-purge symptoms

Personality difficulties

Difficult family relationships

Poor social adjustment

Question 27

What medication can be used in the treatment of anorexia nervosa?

Answer 27

Often no medication is given. SSRI’s can be used to treat co-morbid depression and obsessive-compulsive disorder.

Question 28

What types of psychotherapy are most useful for patients with anorexia nervosa?

Answer 28

Psychoeducation about nutrition and weight

CBT

Interpersonal therapy

Family therapy - important to get family involved

Psychodynamic psychotherapy

Question 29

What medication can be used in the treatment of bulimia nervosa?

Answer 29

High dose SSRIs can be useful to reduce bingeing and purging.