#14081 - Eating Disorders - Psychology

Eating disorders

Classification of eating disorders

• Anorexia nervosa

• Bullimia nervosa

• Binge eating

• Otherwise specified feeding/ eating disorders ED-NOS

Core features: disturbed eating; over evaluation of control of eating, weight, shape- resulting in clinically significant impairment in health and psychosocial function. Also not secondary to any general medical/ psychiatric condition

• Common risk factors

  • Compulsivity – trait; aberrant sense of reward

  • Genetics

  • Female

  • Adolescence

  • Depression

  • substance misuse, alcoholism (more for BN)

  • Obesity (BN)

  • Premorbid experiences

    • Adverse parenting- low contact; high expectations; parental discard

    • Sexual abuse

    • Family dieting

    • Critical comments about eating, weight and shape from others

    • Occupational pressure to be slim- such as in ballets- more so for BN

    • Early menarche (period) – more so for BN

  • Pre morbid characteristics

    • Low self esteem

    • Perfectionism (AN)

    • Anxiety and anxiety disorder – not eating feels better

Overlap between the three disorders mean people cross into other categories over time. Due to the similarities a transiagnostic form of CBT has been developed for full range of eating disorders. This is based on transdiagnostic theory of maintainence

Anorexia nervosa

• Incidence and prevalence

  • Highest mortality rate of any psychiatric disorder

  • Incidence is 8 per 100,000

  • 90% Female

  • Adolescents: 0.3% in teenage girls

  • Excess in higher social classes

• Diagnosis

  • Refusal to maintain body weight over a minimally normal weight for age and height

  • Intense fear of gaining weight or becoming fat, even though underweight

  • Undue influence of body weight or shape on self evaluation or denial of seriousness of the current low body weight

  • In female, absence of least 3 consecutive menstrual cycles when otherwise expected to occur (this has now been removed from DSM-V)

Subtypes:

• Restricting type- during the last 3 months person has not engaged in recurrent episodes of binge eating or purging behaviour

• Binge/Purge type: During the last 3 months, person has engaged in recurrent episodes of binge eating or purging behaviour

• Clinical features- very low BMI

  • Severe mood swings

  • Lack of energy and weakness

  • Slowed thinking; poor memory; Dizziness, fainting, headaches

  • Dry yellowish skin, brittle nails; Growth of fine hair all over the body and face

  • Constipation and bloating

  • Tooth decay and gum damage

Treatment

Target compulsivity due to aberrant reward processing/ corticostriatal circuits common to compulsive disorders

• Training cognitive flexibility

• Reducing pre-occupation

• Training interoceptive/ somatic awareness

• Novel medications acting on reward/ compulsivity pathways

  • Characterise neural circuits with state of art neuroimaging

  • Intervening with neural circuits- neuromodulation- deep brain stimulation

• Current managmenet

  • Help patients see they need help and to maintain motivation

  • Help patients reverse starvation and restore weight

  • Adressing compulsivity and over-evaluation of shape, weight and control over eating

• Cogntivie behavioural therapy- there isn’t a strong evidence base for treatment using CBT

• Compulsory treatment only relevant in few cases Drug treatment doesn’t currently have established role

Bullimia

Incidence and prevalence

• 12 per 100,000

• Western society

• Mostly female

• Young adults rather than adolescents

Diagnosis- DSM-V

• Eating in discrete period of time an amount of food that is larger than most people would eat during a similar period of time and under similar circumstances

• Sense of lack of control over eating during the episode- feeling that one can’t stop eating/control how much one is eating

• Recurrent inappropriate compensatory behaviour to prevent weight gain, such as self induced vomiting, misuse of laxative, diuretics, enemas, or other medications, fasting

• Binge eating and inappropriate compensatory behaviour both occur on average at least once a week for 3 months

Types

Purging type: During the current episode of Bulimia Nervosa the person has regularly engaged in self induced vomiting or misuse of laxative, diuretics or enemas

Non purging type: Other inappropriate compensatory behaviour

Clinical features

• Chronic gastric reflux after eating

• Dehydration and hypokalaemia caused by frequent vomiting

• Electrolyte imbalance cardiac arrhythmia, cardiac arrest

• Esophagitis, rupture of oesophageal due to vomiting

• Constipation

Treatment

• Grade A: specific form of cognitive behavioural treatment – 1/3^rd to make complete recovery

• Grade B : Interpersonal psychotherapy / trial of anti-depressant

Binge eating

Incidence and prevalence

• Later onset; higher proportion in men

Diagnosis

• Recurrent periods of binge eating

• > weekly for > 3 months

• No compensatory behaviours

• No over evaluation of control of eating, weight and shape

Treatment

• Cognitive behavioural therapy

Empirical evidence starvation studies

Minnesota study- Keys et al 1950

• 36 young healthy men

• 3 month baseline

• 6 month period of severe dietary restriction (50%) prior intake

• 3 month re-feeding phase

Key changes

• Preoccupation...