binge eating disorder

**DSM-5 diagnostic criteria** - Recurrent binge eating episodes: eating, in a discrete period (e.g., within 2 hours), an amount definitely larger than most people would eat, with a sense of lack of control over eating. - Binges are associated with ≥3 of the following: eating much more rapidly than normal; eating until uncomfortably full; eating large amounts when not physically hungry; eating alone because of embarrassment; feeling disgusted, depressed, or guilty afterward. - Marked distress about the binge eating. - Occurs on average at least once per week for 3 months. - NOT associated with recurrent inappropriate compensatory behaviors (vomiting, laxatives, diuretics, fasting, excessive exercise) and does not occur exclusively during anorexia nervosa or bulimia nervosa. - Severity is graded by the number of episodes per week: mild 1–3, moderate 4–7, severe 8–13, extreme ≥14.

**Epidemiology and risk factors** - Most common eating disorder in the US, more common than anorexia and bulimia combined. - Female > male, but the male:female ratio is less skewed than in AN/BN. Onset is typically in late adolescence or early adulthood. - Strongly associated with obesity (though many people with obesity do not have BED and not all with BED are obese), depression, anxiety, substance use, and a history of dieting or weight stigma. - Familial and genetic contributions; dysregulated reward and impulse-control circuitry (dopaminergic) is implicated.

**Clinical significance and complications** - Normal or elevated BMI is typical, and vital signs and electrolytes are usually normal because there is no purging. - Complications are those of obesity: type 2 diabetes, metabolic syndrome, hypertension, dyslipidemia, GERD, OSA, NAFLD, and osteoarthritis. - Psychiatric comorbidity is common: depression, anxiety, and PTSD.

**Key differentiators (high-yield)** - **Bulimia nervosa:** also has binges, but with compensatory behaviors (purging or non-purging) and self-evaluation overly influenced by body shape. Patients are usually normal weight. Complications include hypokalemic metabolic alkalosis, Russell sign, parotid enlargement, and dental enamel erosion. - **Anorexia nervosa, binge-purge type:** BMI is low (underweight) and there is a restriction of intake. - **Night eating syndrome:** recurrent nocturnal eating or excessive evening intake with awareness and recall. - **Kleine-Levin syndrome:** episodic hypersomnia with hyperphagia. - **Atypical depression:** increased appetite, hypersomnia, and mood reactivity, but episodic binges with loss of control are not the core feature.

**Management** - **First-line:** psychotherapy, specifically CBT (CBT-E), with interpersonal therapy (IPT) and dialectical behavior therapy (DBT) as alternatives. - **Pharmacotherapy:** - **Lisdexamfetamine** is the only FDA-approved drug for moderate-to-severe BED in adults. It is a prodrug of dextroamphetamine, so monitor for insomnia, increased BP and HR, and abuse potential. It is not indicated for weight loss. - SSRIs (e.g., fluoxetine), topiramate, and others reduce binge frequency, but evidence is weaker. - **Avoid bupropion** in bulimia nervosa because of seizure risk. This is a classic boards point, but it also applies to eating disorders with purging more generally. - Treat comorbid medical and psychiatric conditions. Weight-loss strategies (e.g., GLP-1 agonists) may be considered for coexisting obesity, but behavioral treatment of the eating pathology comes first.

**Exam pearl:** A patient with recurrent episodes of eating large amounts with loss of control, marked guilt, and obesity but NO purging, laxative use, or excessive exercise = binge eating disorder. Best initial treatment = CBT. Drug of choice if medication is used = lisdexamfetamine.