Eating Disorders: Anorexia & Bulimia Nervosa - Comprehensive Notes
Eating Disorders: Anorexia & Bulimia Nervosa
Overview
Eating disorders are characterized by irregular eating habits and extreme distress or concern about body weight or shape.
These disorders involve inadequate or excessive food intake, which can harm a person’s well-being.
Common forms include anorexia nervosa, bulimia nervosa, binge-eating disorder, pica, rumination disorder, avoidant/restrictive food intake disorder (ARFID), and other specified feeding or eating disorder (OSFED).
What are Eating Disorders?
Eating disorders involve repeated disturbances of eating or eating-related behavior, resulting in altered food consumption or absorption.
These disturbances significantly diminish physical health or psychosocial functioning.
Continuum of Eating Disorders:
Anorexia nervosa: Eating too little or self-starvation.
Bulimia nervosa: Chaotic eating patterns.
Obesity: Eating too much.
Historical Context:
Middle Ages: Documentation of willful dieting leading to self-starvation in female saints.
Late 1800s: Doctors described young women using self-starvation to avoid obesity.
1960s: Anorexia nervosa established as a mental disorder.
1979: Bulimia nervosa described as a distinct syndrome.
Types of Eating Disorders
Anorexia Nervosa:
Life-threatening disorder characterized by refusal or inability to maintain a minimally normal body weight.
Intense fear of gaining weight or becoming fat.
Significantly disturbed perception of body shape or size.
Inability or refusal to acknowledge the seriousness of the problem.
Bulimia Nervosa:
Recurrent episodes (at least twice a week for 3 months) of binge eating followed by inappropriate compensatory behaviors to avoid weight gain.
Compensatory behaviors include purging, fasting, or excessive exercising.
Binge-Eating Disorder (BED):
Recurrent episodes of binge eating without the recurrent use of inappropriate compensatory behaviors.
Does not occur exclusively during bulimia nervosa or anorexia nervosa.
No compensatory methods for overeating, such as self-induced vomiting.
Pica:
Persistent eating of non-nutritive substances (e.g., hair, dirt, paint chips) for at least one month.
Rumination Disorder:
Repeatedly and persistently regurgitating food after eating.
Not due to a medical condition or another eating disorder.
Avoidant/Restrictive Food Intake Disorder (ARFID):
Persistent failure to meet appropriate nutritional or energy needs.
Due to lack of interest in eating, aversion to sensory characteristics of food, or fear of choking.
Other Specified Feeding or Eating Disorder (OSFED):
Eating behaviors that cause clinically compelling distress and impairment in functioning.
Do not meet the full criteria for other feeding and eating disorders.
Causes
A specific cause for eating disorders is unknown; dieting may be the initial stimulus.
Biologic Factors:
Studies indicate that anorexia nervosa tends to run in families.
Genetic vulnerability may result from personality type or susceptibility to psychiatric disorders.
Developmental Factors:
Onset of anorexia nervosa often occurs during adolescence or young adulthood.
Causes may be related to developmental issues.
Family Influences:
Girls growing up amid family problems and abuse are at higher risk for anorexia and bulimia.
Disordered eating can be a response to family discord.
Sociocultural Factors:
Adolescents idealize actresses and models with the “perfect” body, even if they are underweight or use special effects.
Pressure from others contributes to eating disorders.
Statistics and Incidences
Obesity is a major health problem in the United States.
Millions of women either starve themselves or engage in chaotic eating patterns leading to death.
30% to 35% of normal-weight people with bulimia have a history of anorexia nervosa and low body weight.
About 50% of people with anorexia nervosa exhibit bulimic behavior.
More than 90% of cases of anorexia nervosa and bulimia occur in females (American Psychiatric Association, 2000).
The prevalence of both eating disorders is estimated to be 1% to 3% of the general population in the United States.
Clinical Manifestations
Symptoms of Anorexia Nervosa:
Fear of gaining weight or becoming fat, even when severely underweight.
Body image disturbance.
Amenorrhea or absence of menstrual period.
Depressive symptoms (e.g., depressed mood, social withdrawal, irritability, insomnia).
Preoccupation with thoughts of food.
Feelings of ineffectiveness.
Inflexible thinking.
Strong need to control environment.
Limited spontaneity and overly restrained emotional expression.
Complaints of constipation and abdominal pain.
Cold intolerance.
Lethargy.
Emaciation.
Hypotension, hypothermia, bradycardia.
Hypertrophy of salivary glands.
Elevated BUN.
Electrolyte imbalances.
Leukopenia and mild anemia.
Elevated liver function studies.
Symptoms of Bulimia Nervosa:
Recurrent episodes of binge eating.
Compensatory behavior such as self-induced vomiting, misuse of laxatives, diuretics, enemas, or excessive exercise.
Self-evaluation overly influenced by body shape and weight.
Usually within normal weight range, possible underweight or overweight.
Restriction of total calorie consumption between binges, selecting low-calorie foods while avoiding foods perceived as fattening or likely to trigger a binge.
Depressive and anxiety symptoms.
Possible substance use involving alcohol and stimulants.
Loss of dental enamel.
Chipped, ragged, or moth-eaten appearance of teeth.
Increased dental caries.
Menstrual irregularities.
Dependence on laxatives.
Esophageal tears.
Fluid and electrolyte abnormalities.
Metabolic alkalosis (from vomiting) or metabolic acidosis (from diarrhea).
Mildly elevated serum amylase levels.
Assessment and Diagnostic Findings
Diagnostic Tests and Assessment Cues:
Physical and mental status evaluation.
Physiological condition (weight, vital signs, physical complications).
Psychological well-being (body image, mood disturbances, cognitive distortions).
Complete blood count (CBC).
Hemoglobin levels typically normal, elevations in dehydration.
White blood cell count (WBC) typically low due to increased margination.
Thrombocytopenia is also observed.
Blood chemistries.
Hyponatremia (excess water intake or inappropriate secretion of antidiuretic hormone).
Hypokalemia (diuretic or laxative use).
Hypoglycemia (lack of glucose precursors or low glycogen stores; impaired insulin clearance).
Elevated blood urea nitrogen (renal function normal except in dehydration).
Hypokalemic hypochloremic metabolic alkalosis (vomiting).
Acidosis (laxative abuse).
Liver function tests.
Minimally elevated, albumin and protein levels usually normal.
Medical Management
Medical management focuses on weight restoration, nutritional rehabilitation, rehydration, and correction of electrolyte imbalances.
Nutritional rehabilitation and weight restoration.
Clients receive nutritionally balanced meals and snacks that gradually increase caloric intake to a normal level for size, age, and activity.
Family-based therapy.
Individuals with anorexia nervosa may respond best to family-based treatment, also known as the Maudsley method, an established therapeutic modality for achieving and maintaining remission from anorexia nervosa.
Cognitive behavioral therapy (CBT).
CBT is an evidence-based, effective treatment for bulimia nervosa (BN); behavioral approaches to avoiding undesirable eating habits are used, including diary keeping; behavioral analyses of the antecedents, behaviors, and consequences (so-called ABCs) associated with binge eating and purging episodes; and exposure to food paired with progressive response prevention regarding binge eating and purging.
Interpersonal psychotherapy.
Interpersonal psychotherapy (IPT) addresses specific issues in the interpersonal arena that create the context for and stimulate dynamic tensions that spur the patient’s symptoms; these generally encompass such processes as grief, role transitions, role conflicts or disputes, and interpersonal deficits.
Pharmacologic Management
Several classes of drugs have been studied, but few have shown clinical success.
Electrolyte supplements.
Electrolyte repletion is necessary in patients with profound malnutrition, dehydration, and purging behaviors; repletion may be done orally or parenterally, depending on the patient’s clinical state.
Fat-soluble vitamins.
Vitamins are used to meet necessary dietary requirements. They are utilized in metabolic pathways, as well as in deoxyribonucleic acid (DNA) and protein synthesis.
Antidepressants, SSRIs.
These agents have been reported to reduce binge eating, vomiting, and depression and to improve eating habits, although their impact on body dissatisfaction remains unclear.