What is the role of Selective Serotonin Reuptake Inhibitors (SSRIs) in treating eating disorders, such as anorexia nervosa and bulimia nervosa?

From the Guidelines

Selective Serotonin Reuptake Inhibitors (SSRIs) can be used in the treatment of eating disorders, but their use varies depending on the specific disorder, with stronger evidence supporting their use in bulimia nervosa than anorexia nervosa. For bulimia nervosa, fluoxetine (Prozac) is FDA-approved at doses of 60mg daily, higher than typical depression dosing, and has been shown to reduce binge-purge behaviors by 50-70% 1. Treatment typically continues for at least 6-12 months after symptom improvement. For anorexia nervosa, SSRIs have limited efficacy during the underweight phase but may be more beneficial after weight restoration, particularly for preventing relapse and addressing comorbid anxiety or depression 1. Common SSRIs used include fluoxetine, sertraline (50-200mg daily), escitalopram (10-20mg daily), and citalopram (20-40mg daily) 1. These medications work by increasing serotonin levels in the brain, which helps regulate mood, appetite, and obsessive thoughts about food and body image. Side effects may include nausea, headache, insomnia, and sexual dysfunction. It's essential to note that medication should be part of a comprehensive treatment approach that includes nutritional rehabilitation, psychotherapy (particularly cognitive behavioral therapy), and medical monitoring, as SSRIs alone are rarely sufficient to treat eating disorders 1. Some key points to consider when using SSRIs in eating disorders include:

• The importance of a comprehensive treatment plan that incorporates medical, psychiatric, psychological, and nutritional expertise 1
• The need for individualized goals for weekly weight gain and target weight in patients with anorexia nervosa 1
• The recommendation for eating disorder-focused cognitive-behavioral therapy and a serotonin reuptake inhibitor (e.g., 60 mg fluoxetine daily) in adults with bulimia nervosa 1

From the FDA Drug Label

In the controlled clinical trials of fluoxetine supporting its effectiveness in the treatment of bulimia nervosa, patients were administered fixed daily fluoxetine doses of 20 or 60 mg, or placebo Only the 60–mg dose was statistically significantly superior to placebo in reducing the frequency of binge–eating and vomiting Consequently, the recommended dose is 60 mg/day, administered in the morning.

Not all SSRIs are approved for eating disorders.

• The provided drug label only supports the use of fluoxetine in the treatment of bulimia nervosa at a dose of 60 mg/day.
• There is no information in the provided drug labels that directly supports the use of all SSRIs in eating disorders, including anorexia nervosa.
• Fluoxetine is the only SSRI mentioned in the provided drug labels as being studied for the treatment of bulimia nervosa.
• The use of other SSRIs in eating disorders may not be supported by the FDA drug label 2, 2.

From the Research

Role of SSRIs in Eating Disorders

• SSRIs are not universally approved for all eating disorders, with fluoxetine being the only SSRI approved for bulimia nervosa 3.
• For anorexia nervosa, there are no approved pharmacological options, although olanzapine and dronabinol have shown promising results in studies 3.
• SSRIs, such as fluoxetine, can be effective in reducing symptoms of bulimia nervosa, including binge eating and vomiting episodes, regardless of the presence of comorbid depression 4.
• The use of SSRIs in eating disorders has yielded mixed results, with some studies suggesting their effectiveness in reducing symptoms, while others have found limited benefits 5, 6.

Specific SSRIs and Eating Disorders

• Fluoxetine is the most commonly used SSRI in the treatment of bulimia nervosa and has been shown to be effective in reducing symptoms 5, 6, 4.
• Other SSRIs, such as sertraline and paroxetine, have also been used to treat eating disorders, although their effectiveness is less well-established 5, 6.
• For binge eating disorder, medications that diminish appetite, such as lisdexamfetamine, may be used in addition to SSRIs 7.

Limitations and Future Directions

• The current evidence base for the use of SSRIs in eating disorders is limited, and further research is needed to fully understand their effectiveness and potential benefits 3, 5, 6, 7.
• Novel treatments, such as psychedelics and stimulants, may offer new options for the treatment of eating disorders, although more research is needed to establish their safety and efficacy 3.