Is quetiapine effective for treating anorexia nervosa?

Quetiapine for Anorexia Nervosa

Quetiapine is not recommended as a standard treatment for anorexia nervosa, as current evidence does not support routine pharmacologic treatment for this condition, and psychotherapy combined with nutritional rehabilitation remains the cornerstone of care. 1

Guideline-Based Treatment Framework

First-Line Treatment (No Role for Quetiapine)

• The American Psychiatric Association explicitly states that no medications are approved for anorexia nervosa, and current evidence does not support routine pharmacologic treatment for weight restoration. 1

• Eating disorder-focused psychotherapy combined with nutritional rehabilitation and weight restoration is the primary treatment approach for anorexia nervosa. 1

• For adolescents and young adults, family-based treatment with caregiver involvement is strongly recommended as the first-line intervention. 1

Limited Evidence for Quetiapine Specifically

• In treatment-resistant OCD (a different condition), a randomized controlled trial found that fluoxetine plus quetiapine was significantly inferior to fluoxetine plus placebo and fluoxetine plus clomipramine for symptom reduction. 2 This suggests quetiapine may not be an effective augmentation agent even in related psychiatric conditions.

• A 2010 pilot study showed quetiapine (100-400 mg/day) resulted in psychological and physical improvements with minimal side effects in 33 anorexia nervosa patients, but this was a small, open-label, naturalistic trial without placebo control. 3

• An 8-week open-label study of quetiapine (50-800 mg/day) in eight severely ill anorexia nervosa patients showed significant improvements in restraint scores and BMI over 8 weeks, but only 5 of 8 participants completed the full trial. 4

If Pharmacologic Adjunct Is Considered (Olanzapine, Not Quetiapine)

When adjunctive medication is used alongside psychotherapy and nutritional rehabilitation, olanzapine—not quetiapine—has the strongest evidence base:

• Olanzapine at 5 mg once daily is the recommended starting dose for patients receiving adjunctive pharmacotherapy. 1

• A 2007 review found that olanzapine 2.5-15 mg daily promotes weight gain and has positive effects on psychological symptoms in anorexia nervosa, though evidence remains limited. 5

• A 2010 review concluded that atypical antipsychotics (including quetiapine) appear safe with some evidence of positive effects on depression and anxiety, but insufficient evidence exists to confirm they enhance weight gain in anorexia nervosa. 6

• A 2025 German guideline update notes that studies on olanzapine are heterogeneous, limiting off-label use to individual cases only. 7

Mandatory Pre-Treatment Safety Assessments

Before any psychotropic medication (including quetiapine) is initiated:

• An electrocardiogram must be obtained because QTc prolongation is common in restrictive anorexia nervosa, and both the illness and certain psychiatric drugs can prolong the QTc interval. 1

• Baseline comprehensive metabolic panel including electrolytes is required. 1

• Baseline vital signs with orthostatic blood pressure measurement must be recorded. 1

• Baseline complete blood count should be obtained. 1

Critical Pitfalls to Avoid

• Do not initiate quetiapine or any psychotropic medication without prior cardiac evaluation, as the combination of anorexia nervosa and QT-prolonging drugs creates significant risk. 1

• Do not use pharmacotherapy as a substitute for psychotherapy and nutritional rehabilitation—medications should only be considered as adjuncts in specific circumstances. 1

• Do not assume that appetite stimulants used in cancer-related anorexia (such as megestrol acetate or dexamethasone) are appropriate for anorexia nervosa, as these are different clinical entities. 2

Clinical Bottom Line

Quetiapine lacks sufficient high-quality evidence for anorexia nervosa treatment. The small pilot studies showing potential benefit 3, 4 are insufficient to overcome the guideline consensus that no medications are routinely recommended for this condition. 1 If adjunctive pharmacotherapy is deemed necessary after comprehensive psychotherapy and nutritional interventions, olanzapine has more supporting evidence than quetiapine. 1, 5 All care must be delivered by a coordinated multidisciplinary team with medical, psychiatric, psychological, and nutritional expertise. 1