Understanding Eating Disorders

Introduction to Eating Disorders

• Serious mental health conditions involving preoccupation with food, body weight, and shape.
• Lead to dangerous behaviors affecting physical and mental health.
• Eating disorders were recognized in medical literature with early cases, such as descriptions of anorexia nervosa, appearing in the 19th century

Classification of Eating Disorders (DSM-5 Criteria)

• Eating disorder classifications are based on the DSM-5 criteria

Anorexia Nervosa (AN)

• Characterized by an intense fear of gaining weight, significant restriction of food intake, and markedly low body weight.
• Subtypes include the restricting type and the binge-eating/purging type.
• Physical complications: osteoporosis, amenorrhea, bradycardia, and hypotension.
• Psychiatric comorbidities: depression, anxiety, and obsessive-compulsive traits.

Bulimia Nervosa (BN)

• Diagnosed by recurrent episodes of binge eating followed by inappropriate compensatory behaviors.
• Compensatory behaviors: vomiting, excessive exercise, and laxative use
• Diagnostic criteria include binge and compensatory behaviors occurring at least once a week for three months.
• Physical complications: electrolyte imbalances, esophageal tears, and dental erosion.
• Psychiatric comorbidities include mood disorders and substance abuse.

Binge Eating Disorder (BED)

• Diagnosed by recurrent episodes of eating large quantities of food in a short period and a sense of loss of control and guilt.
• There are no compensatory behaviors in BED
• BED is more common than anorexia and bulimia.
• Complications: obesity, metabolic syndrome, and cardiovascular risks.
• Psychiatric comorbidities: depression, anxiety, and impulsivity.

Other Specified Feeding or Eating Disorder (OSFED)

• Includes clinically significant eating disorders that do not meet full criteria for AN, BN, or BED.
• Examples: atypical anorexia nervosa and purging disorder

Avoidant/Restrictive Food Intake Disorder (ARFID)

• Characterized by avoidance of certain foods due to sensory characteristics, concerns about choking, or lack of interest in eating.
• Complications: nutritional deficiencies and stunted growth in children.

Epidemiology of Eating Disorders

• Anorexia nervosa has a lifetime prevalence of 0.5-1% in females and is significantly lower in males.
• Bulimia nervosa has a prevalence of 1-2% in women and is lower in men.
• Binge eating disorder affects about 2-3% of the general population.
• Eating disorders are more common in women, but the prevalence among men is rising.
• The typical age of onset is adolescence or early adulthood, but it can occur at any age.
• Westernized ideals of thinness contribute to a higher prevalence in certain cultures
• Eating disorders are seen worldwide, regardless of culture.

Etiology and Risk Factors

• Twin studies indicate a genetic component, especially for anorexia nervosa.
• Neurobiological factors include dysregulation in serotonin and dopamine pathways and abnormalities in the hypothalamus.
• Hormonal dysregulation involves changes in leptin, ghrelin, and cortisol levels.
• Cognitive distortions: overvaluation of body shape and weight, perfectionism, and rigid thinking play a role.
• A history of childhood trauma, abuse, or neglect increases vulnerability.
• Personality traits include impulsivity, harm avoidance, and obsessive-compulsive tendencies.
• Sociocultural pressures from media influence and societal standards of beauty emphasizing thinness.
• Family dynamics: family conflict, enmeshment, overprotectiveness, or parental criticism are factors
• Peer pressure and bullying related to body image concerns can contribute.

Neurobiology of Eating Disorders

• The hypothalamus is involved in appetite control
• The insular cortex shows altered interoceptive awareness
• The reward system has altered dopamine functioning, notably in BN and BED.
• Serotonin dysfunction is linked to satiety, mood regulation, and impulse control in AN and BN.

Clinical Features and Presentation

• Anorexia nervosa sufferers exhibit severe weight loss, lanugo, cold intolerance, brittle nails, and hair thinning.
• Bulimia nervosa patients may have normal or slightly above normal weight, parotid gland enlargement, calluses on knuckles (Russell's sign), and dental erosion.
• Binge eating disorder patients may be overweight or obese without physical signs of purging or compensatory behaviors.
• Behavioral symptoms: Preoccupation with food, calories, or dieting, ritualistic eating habits (e.g., cutting food into small pieces), social withdrawal, and avoidance of eating with others
• Psychological symptoms: Distorted body image, extreme fear of gaining weight (AN), and shame, guilt, or secrecy around eating behaviors (BN, BED).

Assessment and Diagnosis

• Comprehensive evaluation includes medical and psychiatric assessments
• A medical assessment includes vital signs, BMI, and lab tests for electrolytes, thyroid function, and liver enzymes.
• Psychiatric assessments screen for comorbid mood disorders, anxiety, OCD, and PTSD.
• Eating disorder inventories include the Eating Disorder Examination Questionnaire (EDE-Q) and the SCOFF Questionnaire (rapid screening tool).
• Body image assessment tools are used.
• Laboratory and imaging tests involve blood tests (e.g., CBC, electrolytes), ECG (for arrhythmias), and DEXA scan (bone density in AN).

Complications and Medical Consequences

• Cardiovascular complications: Bradycardia, hypotension, arrhythmias, and sudden death (especially in AN)
• Gastrointestinal issues include gastroparesis, constipation, and esophageal tears (BN).
• Endocrine problems: amenorrhea, hypoglycemia, thyroid dysfunction, and osteoporosis (AN).
• Renal complications are electrolyte disturbances (hypokalemia, hyponatremia).
• Neurological effects: seizures, cognitive impairment, and peripheral neuropathy.

Treatment Modalities

• Psychotherapy: including CBT, FBT, DBT and IPT are various options
• Cognitive Behavioral Therapy (CBT): Gold standard for BN and BED, focuses on modifying distorted thoughts around body image and food.
• Family-Based Treatment (FBT): Effective for adolescents with AN, empowering families to take control of eating behaviors.
• Dialectical Behavioral Therapy (DBT): Addresses emotional regulation and impulsivity in BN and BED.
• Interpersonal Therapy (IPT): Improves interpersonal relationships to reduce disordered eating behaviors.
• Pharmacotherapy: SSRIs, atypical antipsychotics, topiramate, and lisdexamfetamine
• SSRIs: Fluoxetine (Prozac) is used for BN to reduce binge-purge cycles and may treat depression in AN and BED.
• Atypical Antipsychotics: Olanzapine promotes weight gain in AN and reduces obsessive thinking about weight.
• Topiramate: Reduces binge eating and weight gain in BED.
• Lisdexamfetamine (Vyvanse): FDA-approved for moderate to severe BED.
• Nutritional Rehabilitation: involves supervised meal plans and gradual refeeding for AN to avoid refeeding syndrome.
• Dietitian involvement is essential for meal planning and education.
• Hospitalization criteria include severe malnutrition (BMI < 15), medical instability, suicidality, or failure of outpatient treatment.

Prognosis and Long-Term Outcomes

• Recovery rates:
• AN: 50-70% recovery, but high rates of chronicity and relapse.
• BN: Higher recovery rates than AN; 70-80% show significant improvement.
• BED: Typically has a more favorable outcome with proper treatment.
• Relapse rates are high, particularly in AN, and long-term follow-up is critical.
• Mortality: AN has the highest mortality rate of any psychiatric disorder due to medical complications or suicide.