The antidepressant shows one of the largest drug effects yet reported for a common gut condition
STUDY: Nguyen HT et al, Gastroenterology Research 2026
STUDY TYPE: Meta-analysis
FUNDING: Independent
Background
Functional dyspepsia is when people have chronic gastrointestinal symptoms with no known medical cause. It is common (up to 20% of population, and 3-5% of all primary care visits) and causes fullness, early satiety, epigastric pain, bloating, gas, and mild nausea.
Mirtazapine, an antidepressant that blocks presynaptic alpha-2 and certain serotonin receptors. It is often used for nausea, irritable bowel syndrome, gastroparesis, and helps the stomach relax after eating. This analysis looks at its effects in functional dyspepsia.
The Study
- Three randomized trials (154 patients total) compared mirtazapine, 15 or 30 mg daily, against control for 8 weeks in adults with functional dyspepsia.
- Two trials enrolled patients with weight loss and one required depressive symptoms.
Results
Mirtazapine beat control on symptom severity in all three trials. The pooled effect was large (1.4, 95% CI, −2.0 to −0.78).
Results, however, varied by studies (I2 = 65%), driven mostly by one trial with an especially large effect (SMD 2.24) in patients with weight loss but no depression or anxiety. Dropping that trial cleared the variability, and the benefit held in every sensitivity analysis.
The review did not report on tolerability or dropouts.
Practice Implications
- Consider mirtazapine for depression, anxiety, or insomnia with functional dyspesia, especially with symptoms of poor appetite, early satiety, or unintended weight loss.
—Chris Aiken, MD
Director, Psych Partners
Editor in Chief, Carlat Psychiatry Report
