Eating Disorders: Anorexia and Bulimia Nervosa

• Eating disorders are mental health conditions with preoccupations about food, weight, and shape, leading to harmful behaviors affecting health.
• Historically, eating disorders were recognized in medical literature with early cases like anorexia nervosa descriptions appearing in the 19th century.

Anorexia Nervosa (AN)

• Intense fear of weight gain and food restriction leads to markedly low body weight.
• Subtypes include restricting type and binge-eating/purging type.
• Physical complications include osteoporosis, amenorrhea, bradycardia, and hypotension.
• Psychiatric comorbidities include depression, anxiety, and obsessive-compulsive traits.

Bulimia Nervosa (BN)

• Recurrent binge eating episodes are followed by inappropriate compensatory behaviors like vomiting, excessive exercise, or laxative use.
• Binge and compensatory behaviors occur at least once a week for three months to meet diagnostic criteria.
• Physical complications include electrolyte imbalances, esophageal tears, and dental erosion.
• Psychiatric comorbidities include mood disorders and substance abuse.

Binge Eating Disorder (BED)

• Recurrent episodes involve eating large quantities of food in a short period, accompanied by a sense of loss of control and guilt, without compensatory behaviors.
• It is more common than anorexia and bulimia.
• Complications include obesity, metabolic syndrome, and cardiovascular risks.
• Psychiatric comorbidities include depression, anxiety, and impulsivity.

Other Specified Feeding or Eating Disorder (OSFED)

• Clinically significant eating disorders do not meet the full criteria for AN, BN, or BED.
• Atypical anorexia nervosa and purging disorder are included in this category.

Avoidant/Restrictive Food Intake Disorder (ARFID)

• Avoidance of certain foods results from sensory characteristics, concerns about choking, or lack of interest in eating.
• Complications include nutritional deficiencies and stunted growth in children.

Epidemiology of Eating Disorders

• AN has a 0.5-1% lifetime prevalence in females, with lower rates in males.
• BN has a 1-2% prevalence in women, with lower rates in men.
• BED affects about 2-3% of the general population.
• Eating disorders are more common in women, but prevalence is rising among men.
• Onset typically begins in adolescence or early adulthood but can occur later in life.
• Westernized ideals of thinness contribute to higher prevalence in certain cultures; however, these disorders are seen worldwide.

Etiology and Risk Factors

• Twin studies show the heritability, especially for anorexia nervosa.
• Dysregulation occurs in serotonin and dopamine pathways, along with abnormalities in the hypothalamus.
• Leptin, ghrelin, and cortisol levels change.
• Cognitive distortions include overvaluation of body shape and weight, perfectionism, and rigid thinking.
• Childhood trauma, abuse, or neglect increases vulnerability.
• High levels of impulsivity, harm avoidance, and obsessive-compulsive traits are often exhibited.
• Media influence and societal standards of beauty emphasize thinness.
• Family conflict, enmeshment, overprotectiveness, or parental criticism are factors.
• Peer pressure and bullying related to body image concerns are contributors.

Neurobiology of Eating Disorders

• Hypothalamus dysregulation affects appetite control.
• The insular cortex displays altered interoceptive awareness.
• Altered dopamine functioning affects the reward pathway, especially in BN and BED.
• Serotonin dysfunction is linked to satiety, mood regulation, and impulse control in AN and BN.

Clinical Features and Presentation

• Severe weight loss, lanugo, cold intolerance, brittle nails, and hair thinning are physical signs of AN.
• Normal or slightly above-normal weight, parotid gland enlargement, calluses on knuckles (Russell’s sign), and dental erosion are physical signs of BN.
• Overweight or obese individuals show no physical signs of purging or compensatory behaviors in BED.
• Preoccupation with food, calories, or dieting occurs.
• Ritualistic eating habits develop like cutting food into small pieces.
• Social withdrawal and avoidance of eating with others happens.
• Distorted body image and extreme fear of weight gain are psychological symptoms of AN.
• Shame, guilt, or secrecy surrounds eating behaviors in BN and BED.

Assessment and Diagnosis

• Assessments include vital signs, BMI, and laboratory tests (electrolytes, thyroid function, liver enzymes).
• Screening occurs for comorbid mood disorders, anxiety, OCD, and PTSD.
• Eating Disorder Examination Questionnaire (EDE-Q) and SCOFF Questionnaire act as screening inventories.
• Blood tests (e.g., CBC, electrolytes), ECG (for arrhythmias), and DEXA scans (bone density in AN) are performed.

Complications and Medical Consequences

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

Treatment Modalities

• Cognitive Behavioral Therapy (CBT) is the gold standard for BN and BED, targeting distorted thoughts around body image and food.
• Family-Based Treatment (FBT) empowers families to control eating behaviors, effective for adolescents with AN.
• Dialectical Behavioral Therapy (DBT) addresses emotional regulation and impulsivity in BN and BED.
• Interpersonal Therapy (IPT) focuses on improving interpersonal relationships, which can reduce disordered eating behaviors.

Pharmacotherapy

• SSRIs, especially fluoxetine (Prozac), assist in treating depression for AN and BED and help reduce binge-purge cycles for BN.
• Atypical antipsychotics, e.g., olanzapine, promote weight gain in AN and obsessive thinking about weight.
• Topiramate may help reduce binge eating and weight gain in BED.
• Lisdexamfetamine (Vyvanse) is FDA-approved for moderate to severe BED.
• Supervised meal plans with gradual refeeding for AN to avoid refeeding syndrome are key.
• Dietitian involvement provides meal planning and education.

Hospitalization Criteria

• Severe malnutrition (BMI < 15), medical instability (electrolyte imbalances, bradycardia), suicidality, or failure of outpatient treatment.

Prognosis and Long-Term Outcomes

• AN has a 50-70% recovery rate but high rates of chronicity and relapse.
• BN has higher recovery rates than AN, with 70-80% showing significant improvement.
• BED outcomes are more favorable with appropriate treatment.
• Relapse rates are high, particularly in AN, so long-term follow-up is critical.
• AN has the highest mortality rate of any psychiatric disorder due to medical complications or suicide.

Overview of eating disorders, focusing on anorexia nervosa (AN) and bulimia nervosa (BN). Includes diagnostic criteria, subtypes, physical complications like osteoporosis and electrolyte imbalances, and psychiatric comorbidities such as depression and anxiety.