Psychiatry: Feeding or Eating Disorders (Pearls)
| FEEDING OR EATING DISORDERS |
| Anorexia nervosa |
Patient will present as → a 16-year-old ballet dancer whose weight has fallen far below expected for age and height. She eats tiny portions, runs daily, and sees herself as “fat” despite her emaciated appearance. Heart rate is 42, and she insists nothing is wrong. Patient who refuses to eat due to fear of being overweight
- Highest mortality of any psychiatric disorder — starvation + suicide
- Two types: restricting (severe restriction, excess exercise) vs binge-eating/purging (laxatives, diuretics, vomiting)
- Distinguished from bulimia by low weight — bulimia patients are typically normal weight or overweight
DX: DSM-5 — significantly low body weight + intense fear of weight gain + disturbed body image (or persistent denial of the seriousness of low weight)
- Severity tracks with BMI (mild ≥ 17 → extreme < 15); amenorrhea is no longer required
- Screen labs/ECG: bradycardia, hypokalemia, hypophosphatemia, prolonged QT
TX: Restore nutrition + psychotherapy as the core treatment — CBT for adults, family-based treatment (Maudsley) for adolescents
- Hospitalize for < 70–75% expected body weight, bradycardia < 40, hypotension, hypothermia, electrolyte derangement, or arrhythmia
- ⚠️ Refeed slowly and monitor phosphorus — refeeding syndrome (hypophosphatemia, arrhythmias) kills
- No medication reliably treats anorexia — olanzapine has modest evidence; avoid bupropion in any purging patient (seizure risk)
|
| Avoidant/restrictive food intake disorder (ARFID) |
Patient will present as → a 9-year-old boy whose diet consists of five “safe” foods; he gags at new textures and has fallen from the 50th to the 10th percentile for weight. After choking on a hot dog last year he refuses most solid food, yet he has no concern about body shape or weight and wishes he could “eat like other kids.” Severe food restriction WITHOUT any body-image disturbance or fear of weight gain — the whole distinction from anorexia
- Three classic drivers: sensory aversion (textures, smells) · fear of an aversive consequence (choking, vomiting) · apparent lack of interest in eating
- Typically begins in childhood; strongly associated with autism spectrum disorder and anxiety disorders
DX: DSM-5 — an eating/feeding disturbance failing nutritional or energy needs, with ≥ 1 of: significant weight loss or faltering growth · significant nutritional deficiency · dependence on enteral feeding or supplements · marked psychosocial interference
- Not explained by food scarcity or cultural practice; no body-image disturbance; not exclusively during anorexia or bulimia
- Workup: growth curves; CBC, iron studies, vitamin D, B12, electrolytes; exclude organic causes of poor intake
TX: Nutritional rehabilitation + CBT-AR (graded exposure to avoided foods) — family-based approaches for younger children
- Correct deficiencies; oral supplements before tube feeding; feeding/occupational therapy for sensory cases
- No FDA-approved medication — treatment is behavioral and nutritional
|
| Binge eating disorder |
Patient will present as → a 35-year-old woman with a BMI of 32 who describes eating large amounts rapidly, alone, until uncomfortably full, twice weekly for the past year, with intense guilt afterward — but she never vomits, fasts, or over-exercises to compensate. Screening labs show prediabetes. Recurrent binges with loss of control and marked distress — but NO compensatory purging, fasting, or excessive exercise
- The most common eating disorder in the United States; patients are typically normal weight to obese
- vs bulimia: the absence of compensatory behavior is the single separating feature
- Screen for metabolic comorbidities (diabetes, hypertension, dyslipidemia) plus depression and anxiety
DX: DSM-5 — binge episodes ≥ 1/week for 3 months with loss of control and marked distress
- ≥ 3 of: eating much more rapidly than normal · until uncomfortably full · large amounts when not hungry · alone out of embarrassment · disgust/depression/guilt afterward
- No recurrent compensatory behavior; severity graded by binges/week (mild 1–3 → extreme ≥ 14)
TX: Psychotherapy first-line — CBT preferred (interpersonal therapy is a reasonable alternative); the target is the binge cycle, not the weight
- Lisdexamfetamine — FDA-approved for moderate-to-severe BED; avoid with cardiovascular disease or stimulant-misuse risk
- Alternatives: SSRIs, topiramate; treat metabolic disease in parallel
|
| Bulimia nervosa |
Patient will present as → a 19-year-old college student of normal weight with calluses on her knuckles (Russell sign), swollen parotid glands, and dental erosions. She describes weekly binges followed by self-induced vomiting, and labs show hypokalemic metabolic alkalosis. Patient who has episodes of mass eating followed by self-induced vomiting or intense exercise
- Compensation by vomiting, laxative/diuretic abuse, fasting, or excessive exercise; patients are disturbed by their behavior
- Classic exam picture: Russell sign + parotid swelling + dental erosions + normal weight + hypokalemia
- Purging labs: hypokalemic, hypochloremic metabolic alkalosis with volume depletion
DX: DSM-5 — binge eating + recurrent compensatory behavior, both ≥ 1/week for 3 months
- Self-evaluation unduly influenced by body shape and weight
- Does not occur exclusively during anorexia — low weight reroutes the diagnosis to anorexia, binge-purge type
TX: CBT + nutritional rehabilitation first-line
- Fluoxetine 60 mg daily — the FDA-approved medication (higher than the usual depression dose)
- Bupropion is contraindicated — seizure risk in purging patients; correct potassium and volume status
|
Back to Psychiatry and Behavioral Health Rotation
