8.4 Anorexia Nervosa

Overview of Eating Disorders

Prevalence of Eating Disorders

  • Nearly two out of three U.S. adults struggle with issues related to being overweight.
  • A smaller but notable portion of the population suffers from eating disorders, often resulting in normal weight or underweight conditions due to a fear of gaining weight.
  • Disorders like bulimia nervosa and anorexia nervosa lead to severe health consequences (Mayo Clinic, 2012a, 2012b).

Definition of Anorexia Nervosa (AN)

  • Anorexia nervosa is characterized by a body weight significantly below the average caused by extreme starvation and/or excessive exercise.
  • Individuals with AN often exhibit distorted body image, perceiving themselves as overweight despite being underweight.

Signs and Symptoms of Anorexia Nervosa

General Symptoms

  • Patients may:
    • Perceive themselves as overweight even when underweight.
    • Weigh themselves obsessively.
    • Severely restrict their food intake.
    • Engage in excessive exercise.
    • Induce vomiting or misuse laxatives to control weight.

Specific Signs

  • Extremely restricted eating
  • Extreme thinness (emaciation)
  • Relentless pursuit of thinness and refusal to maintain a healthy weight
  • Intense fear of gaining weight
  • Distorted body image, heavily influencing self-esteem
  • Denial regarding the severity of low body weight

Mortality Rate

  • Anorexia nervosa has the highest mortality rate of any mental disorder, with deaths resulting from starvation complications and suicide.

DSM-5 Criteria for Anorexia Nervosa

  • Anorexia is sub-categorized into:
    1. Restrictive subtype
    2. Binge-eating/purging subtype
  • Diagnosis is confirmed when:
    • Body weight is less than 85% of the normal BMI.
    • Accompanied by a profound fear of weight gain and distorted body image.

Additional Symptoms Over Time

  • Mild anemia and muscle wasting
  • Brittle hair and nails
  • Dry and yellowish skin
  • Growth of lanugo (fine hair on body)
  • Severe constipation
  • Low blood pressure, slowed heart rate and breathing
  • Damage to heart structure and function
  • Difficulty in concentration
  • Potential brain damage
  • Multiorgan failure
  • Drop in internal body temperature leading to constant cold sensation
  • Lethargy or chronic tiredness
  • Amenorrhea (loss of menstrual periods)
  • Infertility

Epidemiology of Anorexia Nervosa

Statistics

  • Anorexia affects approximately:
    • 0.3% to 2% of young women
    • 0.1% to 0.3% of young men
  • Females aged 15 to 24 are at a ten times higher risk of dying from this disorder compared to their peers.
  • Males with anorexia face a heightened risk of late diagnosis due to sociocultural factors.

Etiology of Anorexia Nervosa

Genetic Factors

  • Anorexia has a heritability rate between 28% to 58% and often exceeds 50% in higher estimates.
  • First-degree relatives of those with anorexia have approximately 12-fold increased risk of developing the disorder.
    • Studies suggest associations with 43 genes related to eating behaviors and psychological traits.
  • Epigenetic modifications like DNA methylation may also contribute to the disorder's development.

Environmental Factors

  • Obstetric, prenatal, and perinatal complications (e.g., preterm birth, maternal diabetes) may impact the risk for anorexia.
  • Neuroendocrine dysregulation affecting hunger and satiety signals may play a role.
  • Presence of gastrointestinal disorders increases vulnerability to eating disturbances, particularly restrictive eating practices.
  • Some complications can create food aversions or anxiety leading to disordered eating.

Psychological Factors

  • Early theories linked anorexia to childhood trauma but evidence is inconsistent; low self-esteem, feelings of control loss, depression, and anxiety are also significant contributors.

Sociological Factors

  • Vulnerability to societal body ideals, especially since the 1950s, has increased incidence of anorexia, particularly among those in body-sensitive professions (e.g., modeling, athletics).
  • Family dynamics, cultural pressures, and bullying can exacerbate psychological symptoms.

Media Influence

  • Constant exposure to media promoting unrealistic body ideals can increase body dissatisfaction and contribute to anorexia.
  • Men's magazines show greater focus on body shape, whereas women's media often presents weight loss as more appealing.
  • Pro-anorexia websites promote harmful ideals and distort reality by showcasing manipulated images.

Treatment Approaches

Multidisciplinary Treatment Plan

  • Patients benefit from a combination of nutritional support, psychological counseling, and behavioral modification.
  • Treatment aggressiveness is tailored to the patient's health stability, with high-risk patients often needing inpatient care.

The Maudsley Method

  • A family-oriented treatment strategy involving:
    1. Weight restoration through parental assistance.
    2. Familial dynamics adjustment to aid recovery.
    3. Promoting independence and healthy identity post-weight gain.

Nutritional Therapy

  • Focuses on promoting weight gain, generally estimated at 2-3 pounds per week in inpatient care, and 1 pound per week in outpatient settings.
  • It is crucial to approach patients with empathy rather than a punitive manner.

Medication Options

  • Limited evidence supports the use of antidepressants or antipsychotics in promoting weight gain or reducing distress.

Psychotherapy for Recovery

  • Once weight stabilization is achieved, the focus shifts to recognizing distorted food perceptions and handling emotions to prevent relapse.
  • Approximately 50% of patients relapse within a year of being discharged from treatment programs.