Can Selective Serotonin Reuptake Inhibitors (SSRIs) be used to treat overeating?

SSRIs in Overeating: Evidence-Based Recommendations

SSRIs can be effective for treating overeating, but only in specific contexts: fluoxetine 60 mg daily is recommended for bulimia nervosa, while SSRIs have a more limited role in binge-eating disorder where they are suggested only as second-line options after psychotherapy or when patients prefer medication. 1

Clinical Context Matters: Define the Type of Overeating

The effectiveness of SSRIs depends critically on the specific eating disorder diagnosis:

Bulimia Nervosa (Binge-Eating with Purging)

• Fluoxetine 60 mg daily is the only FDA-approved medication for an eating disorder and should be prescribed either initially or if minimal response to psychotherapy occurs by 6 weeks. 1, 2
• The American Psychiatric Association gives this a 1C recommendation (strong recommendation, moderate evidence quality) for adults with bulimia nervosa alongside eating disorder-focused cognitive-behavioral therapy. 1
• Fluoxetine has demonstrated efficacy in reducing both binge-eating episodes and compensatory purging behaviors in 8-16 week trials. 2, 3
• The 60 mg dose is specifically required—this is higher than typical antidepressant dosing and is necessary for anti-bulimic effects. 2, 4

Binge-Eating Disorder (Overeating Without Purging)

• SSRIs are second-line options for binge-eating disorder; first-line treatment is eating disorder-focused cognitive-behavioral therapy or interpersonal therapy. 1
• The American Psychiatric Association suggests (2C recommendation—weaker evidence) that adults with binge-eating disorder who prefer medication or have not responded to psychotherapy can be treated with antidepressants. 1
• Both sertraline (100-200 mg/day) and fluoxetine (40-80 mg/day) showed effectiveness in reducing binge frequency and achieving weight loss over 24 weeks in obese patients with binge-eating disorder. 5
• After 8 weeks of SSRI treatment, significant improvements in binge-eating scores and weight loss emerged, with responders (≥5% weight loss) maintaining results through 24 weeks. 5

General Obesity Without Eating Disorder

• SSRIs are NOT indicated for weight management in general obesity. 1
• Some SSRIs (particularly paroxetine) actually cause weight gain during long-term treatment, making them problematic for patients with obesity. 1, 6
• FDA-approved weight management medications for obesity include liraglutide, semaglutide, tirzepatide, phentermine/topiramate, naltrexone/bupropion, and orlistat—but not SSRIs. 1

SSRI Selection Algorithm for Eating Disorders

If treating bulimia nervosa:

• Start fluoxetine 60 mg daily (the only evidence-based and FDA-approved option). 1, 2, 4
• This dose is specifically required for bulimia—lower doses used for depression are insufficient. 2

If treating binge-eating disorder and medication is chosen:

• Consider sertraline 100-200 mg/day or fluoxetine 40-80 mg/day as alternatives when psychotherapy has failed or is unavailable. 5
• However, lisdexamfetamine has stronger evidence for binge-eating disorder (though not approved in all countries). 1, 4
• Topiramate also shows good effectiveness in reducing binge frequency and body weight in both bulimia nervosa and binge-eating disorder. 3, 7

If the patient has comorbid obesity:

• Avoid paroxetine entirely—it carries the highest risk for weight gain among SSRIs. 6
• Prefer sertraline or fluoxetine, which are associated with weight neutrality or potential weight loss. 6, 5
• Consider bupropion as a non-SSRI alternative if depression is the primary target, as it is the only antidepressant consistently associated with weight loss. 6, 8

Critical Caveats and Common Pitfalls

Contraindications

• Bupropion is contraindicated in both anorexia nervosa and bulimia nervosa due to seizure risk. 1, 7
• Patients with a history of seizures or conditions predisposing to seizures (including eating disorders with purging) should not receive bupropion. 1

Medication-Induced Weight Gain

• Review all concomitant medications and minimize those promoting weight gain, including certain antipsychotics (clozapine, olanzapine, risperidone), tricyclic antidepressants, some SSRIs (paroxetine), glucocorticoids, and beta-blockers. 1, 6
• Mirtazapine causes significant weight gain through antihistamine properties and should be avoided in patients with obesity or metabolic concerns. 8

Duration of Treatment

• SSRI treatment for eating disorders requires long-term continuation to maintain benefits—sudden discontinuation often results in relapse. 1
• Fluoxetine demonstrated maintenance of response in bulimia nervosa for up to 52 weeks in controlled trials. 2
• For binge-eating disorder, 6-month SSRI treatment appears necessary for sustained benefit. 5

Monitoring Requirements

• Assess response by 6-8 weeks; if minimal improvement, intensify treatment with additional approaches. 1, 5
• Monitor for weight changes, binge frequency, and metabolic parameters (especially in patients with obesity or diabetes). 1, 6
• Screen for malnutrition in patients who have lost significant weight, particularly with combination treatments. 1

Integration with Psychotherapy

• Pharmacotherapy should always be embedded in a comprehensive treatment plan including psychotherapy and nutritional management. 4, 7
• Eating disorder-focused cognitive-behavioral therapy remains the primary treatment modality, with SSRIs serving as adjuncts. 1