Anorexia Nervosa - Anatomy of Psych

What is anorexia nervosa?

Anorexia nervosa is an eating disorder characterized by a fear of gaining weight, strong desire to be thin, and food restriction, resulting in low weight. It is the psychiatric illness with the highest mortality rate (10%). The yearly prevalence of anorexia amongst young females in the United States is 0.4%. This disorder primarily affects women (10:1 ratio) and usually begins during adolescence or early adulthood.

What does anorexia look like?

Signs & Symptoms

Extreme weight loss or not making expected developmental weight gains
Thin appearance
Abnormal blood counts
Fatigue
Insomnia
Dizziness or fainting
Bluish discoloration of the fingers
Hair that thins, breaks, or falls out
Soft, downy hair covering the body
Absence of menstruation
Constipation and abdominal pain
Dry or yellowish skin
Intolerance of cold
Irregular heart rhythms
Low blood pressure
Dehydration
Swelling of arms or legs
Eroded teeth and calluses on the knuckles from induced vomiting
Severely restricting food intake through dieting or fasting
Exercising excessively
Bingeing and self-induced vomiting to get rid of food, which may include the use of laxatives, enemas, diet aids, or herbal products
Lack of insight regarding weight loss or low weight
Obsessive-compulsive symptoms, both related and unrelated to food
Preoccupation with thoughts of food

DSM-5 Criteria

Criterion A. Restriction of energy intake relative to requirements, leading to a significantly low body weight in the context of age, sex, developmental trajectory, and physical health. Significantly low weight is defined as a weight that is less than minimally normal or, for children and adolescents, less than that minimally expected.

Criterion B. Intense fear of gaining weight or of becoming fat, or persistent behavior that interferes with weight gain, even though at a significantly low weight.

Criterion C. Disturbance in the way in which one's body weight or shape is experienced, undue influence of body weight or shape on self-evaluation, or persistent lack of recognition of the seriousness of the current low body weight.

Subtypes & Specifiers

Specifiers:

Restricting type
- In the past 3 months, the individual has not engaged in recurrent episodes of binge eating or purging behavior
- Weight loss is accomplished primarily through dieting, fasting, and/or excessive exercise
Binge-eating/purging type
- In the past 3 months, the individual has engaged in recurrent episodes of binge eating or purging behavior
Severity specifier:
- Mild: BMI ≥17 kg/m²
- Moderate: BMI = 16 to 16.99 kg/m²
- Severe: BMI = 15 to 15.99 kg/m²
- Extreme: BMI <15 kg/m²

Risk Factors

Anxiety disorders
Obsessional traits in childhood
Stressful life events
First-degree biological relatives with the disorder

Differential Diagnosis

Medical conditions
Major depressive disorder
Schizophrenia
Substance use disorders
Social anxiety disorder
Obsessive-compulsive disorder
Body dysmorphic disorder
Bulimia nervosa
Avoidant/restrictive food intake disorder

How is anorexia investigated?

Possible abnormal laboratory findings:
- Hematology - leukopenia, elevated lymphocytes, mild anemia, thrombocytopenia
- Electrolytes - hyponatremia, hypophosphatemia, hypomagnesemia, hypokalemia, hypocalcemia, hypozincemia, metabolic alkalosis, metabolic acidosis
- Endocrine - low to normal T4, low T3, high rT3
- Cholesterol - high
- Liver enzymes - high
- Serum amylase - high
- Reproductive hormones - low serum estrogen in females, low serum testosterone in males
- Growth hormone - high
- Cortisol - high
- Gonadotropin releasing hormone - low
- Leptin - low
Low bone mineral density with osteopenia or osteoporosis; significant risk of fracture
ECG: sinus bradycardia, arrhythmias
Amenorrhea or delayed menarche
Cold intolerance, hypothermia, lethargy
Hypotension, bradycardia, dizziness, cyanosis, edema
Polyuria
Constipation, non-focal abdominal pain
Lanugo, brittle hair and nails, dry or yellow skin
Petechiae or ecchymoses
Hypertrophy of salivary glands and dental enamel erosion
Scars or calluses on dorsal surface of the hand from repeated contact with the teeth while inducing vomiting

Screening/Scale	Rater	Description
Eating Disorder Diagnostic Scale (EDDS)	Client	22-item scale that screens for several eating disorders

How is anorexia treated?

Cognitive behavioral therapy
Interpersonal therapy
Psychodynamic approaches
Group therapy
Family-based therapy for children and adolescents

Special Considerations

Cultural

Anorexia is most prevalent in high income countries such as Canada, the United States, Australia, New Zealand, Japan, and many European countries. It is also associated with cultures that value thinness and jobs that encourage thinness, such as modelling and dancing.

Refeeding syndrome

Refeeding syndrome can occur when an individual who is significantly malnourished has a sudden increase in calorie intake. Increased caloric intake leads to increased insulin release, which leads to hypophosphatemia, hypokalemia, and hypomagnesemia. These conditions can lead to cardiac complications, seizures, and rhabdomyolysis. There is also a risk of Wernicke's encephalopathy from increased blood sugar and decreased B1 (thiamine).

Nursing Management

Imbalanced nutrition

Causes & Behaviors:

Inadequate food intake
Self-induced vomiting
Chronic or excessive laxative use
Pale conjunctiva and mucous membranes
Poor skin turgor or muscle tone
Edema
Excessive loss of hair, increased growth of hair on the body (lanugo)
Amenorrhea
Hypothermia
Bradycardia, cardiac irregularities, hypotension

Interventions:

Supervise the patient during mealtimes and for a specific period after meals (usually one hour)
Establish a minimum weight goal and daily nutritional requirements; record intake
Use a consistent approach
Monitor for choosing lower calorie foods and beverages, hoarding food, and disposing food in various places
Maintain a regular weighing schedule; before breakfast and in the same attire
Weigh the client with him/her facing away from the scale
Monitor exercise program and set limits on physical activities

Disturbed body image

Causes & Behaviors:

Morbid fear of obesity; perceived loss of control in some aspect of life
Personal vulnerability; unmet dependency needs
Dysfunctional family system
Continual negative evaluation of self
Distorted body image (views self as fat even in the presence of normal body weight or severe emaciation)
Expresses little concern, uses denial as a defense mechanism and feels powerless to prevent/make changes
Expressions of shame/guilt
Overly conforming, dependent on others’ opinions

Interventions:

Promote self-concept without moral judgment
Respond with reality when the client makes unrealistic statements
Assist the client to assume control in areas other than dieting and weight loss, such as managing of own daily activities, work, and leisure choices
Help the client formulate goals not related to eating
Encourage the client to express anger and acknowledge when it is verbalized
Refer to occupational or recreational therapy

References

[1] American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.

[2] Boyd, M. A. (2019). Psychiatric & mental health nursing for Canadian practice. Wolters Kluwer.

[3] Townsend, M. C. (2015). Psychiatric mental health nursing. F.A. Davis.