Psychiatry - Eating disorders

Question 1

What questions should be asked as part of the psychiatric assessment of a patient you suspect as having an eating disorder?

Answer 1

Questions should relate to weight, eating, body image and eliciting physical problems associated with weight loss.

Weight:

• current weight
• how often do you weigh yourself?
• what has your weight been in the past? (fluctuations?)

Body image:

• do you feel fat?
• are you dissatisfied with particular parts of your body?
• what do you think about your body shape?

Eating:

• tell me what you eat on a normal day?
• do you ever binge? What do you eat and what do you do afterwards?
• do you eat out with friends?
• have you tried dieting/ sliming pills/ laxatives?

Question 2

Anorexia nervosa

Answer 2

Eating disorder characterised by deliberate weight loss resulting in weight 15% below expected or a BMI <17.5 with secondary endocrine and metabolic disturbances.

Question 3

What is the aetiology of anorexia?

Answer 3

Genetic (MZ > DZ concordance, increased risk if family history)
Dysfunction in 5-HT system
Socioculural factors - thinness attractive
Family relationships - e.g. over involved parents
Personality type - e.g. perfectionism, low self esteem, obsessive traits

Question 4

Risk factors for anorexia

Answer 4

Associated with certain occupations - e.g. ballet and modelling
Co-morbid depression, substance misuse and personality disorder are common

95% are female, peak age is 15-19 years
Higher prevalence in higher socio-economic areas

Question 5

What features in the history suggestive of anorexia?

Answer 5

Weight loss induced by diet restriction and one or more of:

• self induced vomiting
• excessive exercise
• appetite suppressants or diuretics
• laxatives

Morbid fear of fatness
Body image distortion
Loss of libido
Fatigue
Amenorrhoea 
Obsessional thoughts or rituals

Question 6

Examination findings suggestive of anorexia nervosa

Answer 6

Essential to exclude medical causes of weight loss

• gaunt, emaciated
• dehydrated
• have proximal myopathy
• cold extremities
• bradycardia or hypotension
• fine lanugo hair
• exhibit peripheral oedema
• parotid gland enlargement and erosion of tooth enamel (secondary to vomiting)

They may be low in mood. There will be a preoccupation with food and overvalued ideas about weight and appearance. Insight is usually poor.

Question 7

What investigations should be performed on a patient with suspected anorexia?

Answer 7

FBC, U&E, LFT, amylase, lipids, glucose, TFTs, Ca, magnesium, phosphate. ECG due to electrolyte abnormalities. Bone scan may be indicated if osteoporosis is suspected.

Question 8

How is anorexia managed?

Answer 8

Correct medical complications (may require admission)
Psychiatric admission if very low weight or suicide risk
Refeeding via nasogastric tube if necessary
Negotiate dietary aims
Psychoeducation and support
Monitor muscle power, BP, biochemistry, weight
CBT
Family therapy
SSRIs

Question 9

Prognosis of anorexia

Answer 9

Complications include: osteoporosis, arrhythmias, renal failure, pancreatitis, hepatitis, seizures, peripheral neuropathy, suicide

Prognosis is variable. Some patients recover after a single episode, some relapse and some run a chronic deteriorating course over many years. Half of the patients will have no eating disorder at long term follow up. Mortality is 10% due to complications of the eating disorder and suicide. Poor outcome is associated with older age of onset, long duration of illness, lower weight at presentation and poor childhood social adjustment.

Question 10

Definition of bulimia

Answer 10

Eating disorder characterised by uncontrolled binge eating with vomiting/ laxative abuse. There is a preoccupation with body weight and image.

Question 11

Aetiology of bulimia

Answer 11

Those with bulimia are more likely to have a personal and family history of obesity, affective mood disorders and substance abuse. Half have a previous history of anorexia and the aetiology of the two conditions is similar.

Question 12

What risk factors are associated with bulimia?

Answer 12

High prevalence of depression
Deliberate self harm
Impulsivity
Substance abuse

Average age of onset is 18, more common amongst young adolescent females

Question 13

What features in the history suggest bulimia?

Answer 13

There is a persistent occupation with eating and craving for food. Binge eating of up to 20,000kcal in one session occurs. This is followed by self loathing, vomiting and or laxative abuse and starvation.

Question 14

What signs on clinical examination may support the diagnosis of bulimia?

Answer 14

Weight may be normal
Signs of vomiting: dental erosion, finger calluses, calluses on the dorsum of the hand (Russell’s sign), parotid swelling
Menstrual abnormalities occur in 50%
Mood may be low, with self loathing
Preoccupation with body weight and image
More insight than in anorexia and patients are often keen to help

Question 15

Investigations in bulimia

Answer 15

FBC, U&E, LFT, amylase, lipid, glucose, TFTs, Ca, magnesium, phosphate. ECG due to electrolyte imbalance

Question 16

How should bulimia be managed?

Answer 16

Nearly all patients can be managed as outpatients
Medical stabilisation
CBT
Interpersonal psychotherapy
SSRI antidepressants have an antibulimic effect separate from their antidepressant effect - e.g. fluoxetine

Question 17

Prognosis in bulimia

Answer 17

Complications include: cardiac arrhythmias, renal failure, Mallory-Weiss tear, oesophagitis

Majority of patients make a full recovery. CBT is effective for more than half of patients. Poor outcome is associated with depression, personality disturbance, longer duration of symptoms, greater severity of symptoms and substance abuse.