Eating Disorders: Anorexia Nervosa & Bulimia Nervosa Helen Keeley January 2002
Eating Disorders. (ICD F50) • Two syndromes are described [separate (ICD 10 )or on continuum (DSM1V)]:- • Anorexia Nervosa (restricting type) • Bulimia. (purging/ binging type) • Overeating and Vomiting associated with psychological disturbances are also described. Anorexia • peak onset in the mid-teens and a female: male ratio of 10:1. • Prevalence is 0.1% in 11-15 ;1% in 15-18 year old girls Twin studies suggest genetic predisposition important esp. for AN. Cultural factors also very important and AN is largely disorder of developed world.
Anorexia Nervosa.Description of syndrome Disorder characterised by: • Deliberate weight loss induced and/or sustained by the patient. • Occurs most commonly in adolescent girls or young women but boys may also be affected, as may children approaching puberty and women up to the menopause. • The disorder is associated with under nutrition of varying severity, with resulting secondary endocrine and metabolic changes and disturbances of bodily function. • Differential diagnosis includes: • depression; obsessional states; somatic causes of loss of appetite.
Anorexia Nervosa.Diagnostic Criteria For a definite diagnosis all of the following are required: • Bodyweight is maintained at least 15% below that expected or Quetelet’s body-mass index ([weight(kg)/height(m)]2)is 17.5 or less (>14 implies admission) Also failure to make expected weight gain during growth period in prepubertal children. • Weight loss is self-induced and may include self-induced vomiting, purging, excessive exercise, and use of appetite suppressants and / or diuretics. • Body- image distortion and dread of fatness as an intrusive, overvalued idea. • Widespread endocrine disorder involving the hypothalamic-pituitary-gonadal axis, manifested in women as amenorrhoea (except if on OCP) and in men as loss of sexual interest and potency. • If onset is prepubertal, development of secondary sexual characteristics may be delayed or arrested
Bulimia NervosaDescription of syndrome • Syndrome characterised by repeated bouts of overeating and an excessive pre-occupation with the control of body weight. • The age and sex pattern is similar that of Anorexia Nervosa but the age of presentation tends to be slightly later. • The disorder may be a sequel to Anorexia but the opposite may also occur. • Repeated vomiting may give rise to disturbances of body electrolytes, physical complications (tetany, epileptic seizures, cardiac arrhythmias, muscular weakness) and further severe loss of weight.
Bulimia Nervosa :Diagnostic Criteria • For a definite diagnosis all of the following are required:1.There is a persistent preoccupation with eating and an irresistible craving for food leading to bingeing 2.Counteraction of the fattening effects of the food occurs by one of more of the following: self-induced vomiting; purgative abuse; alternating periods of starvation; use of drugs. If IDDM, may neglect insulin treatment.3.Psychopathology consists of a morbid dread of fatness and a sharply defined weight threshold is set that is well below the optimum.
Bulimia Nervosa:Signs and Symptoms Not as severe as Anorexia Nervosa unless occurs as a complication thereof, when it indicates poor prognosis. • Weight may be average or slightly above or below • Similar but less extreme body- image distortion to AN • Marshall’s sign, i.e. lesions on the knuckles • Parotid Enlargement • Dentists may well notice characteristic effects of self-induced vomiting including: • caries which commence at the back of the front teeth • scarring at back of throat from nail abrasions
Prognosis & TreatmentAnorexia Nervosa: Long term Prognosis 50% recover; 30% partly improved 20% run chronic course;>5% mortality Minority progress from restrictive to binge and then to BN Good prognostic features: Early onset; good parent- child relationships; early detection and treatment. Poor Prognostic indicators Greater weight loss; vomiting; binge-eating; greater chronicity and premorbid abnormalities. Treatment Can occur on out-patient basis. Gradual but steady weight restoration is aim within 10% of expected weight. Family Rx to restructure parent child relationships; individual Rx. Include behavioural; antidepressants for weight gain and depression
Prognosis & TreatmentBulimia Nervosa: Under-represented in clinical samples but studies suggest that it may be more common in the general population. Prognosis Often episodic course with remissions and relapses. Long term disturbed eating persists and depression is common Treatment Outpatient with cognitive-behavioural or group Rx. (better than meds.)