EFFICACY OF ANTIDEPRESSANTS IN THE TREATMENT OF IRRITABLE BOWEL SYNDROME: A SYSTEMATIC REVIEW

Abstract

Background: Irritable bowel syndrome (IBS) is a disorder of gut–brain interaction in which antidepressants are used to modulate pathways involved in symptom generation. Evidence for their efficacy remains heterogeneous across drug classes and outcomes. Aim: To systematically evaluate the efficacy of antidepressants in the treatment of IBS across pharmacological classes and outcome domains. Methods: The methodology and reporting structure of this review were informed by the PRISMA framework. Literature searches were conducted in PubMed and Google Scholar to identify studies evaluating antidepressants in adults with irritable bowel syndrome diagnosed according to Rome criteria. Randomized controlled trials were considered the primary source of evidence and were supplemented, where relevant, by open-label, mechanistic, and exploratory studies. Eligible studies reported validated clinical outcomes, including IBS symptom severity, abdominal pain, global improvement, and health-related quality of life. Owing to differences in study design, interventions, and outcome measures, findings were synthesized qualitatively. Results: Tricyclic antidepressants (TCAs) demonstrated the most consistent signal of benefit, particularly for IBS symptom severity, global improvement, and abdominal pain. Selective serotonin reuptake inhibitors (SSRIs) showed inconsistent findings across trials, with effects varying by outcome measure and study design. Evidence for serotonin–norepinephrine reuptake inhibitors (SNRIs) was limited, often derived from add-on or open-label studies, although some randomized trials reported improvements in symptom severity and quality of life. Data for other antidepressants were restricted to a small number of RCTs with endpoint-specific effects. Variability in outcome measures, including IBS-SSS, adequate relief, and quality-of-life instruments, contributed to heterogeneity in reported treatment effects. Conclusions: Antidepressants appear to have a role in IBS management, with the most consistent evidence observed for TCAs. Findings for SSRIs are inconclusive, while evidence for SNRIs and other agents remains limited. Interpretation is constrained by variability in outcome measures and study design. Further well-designed RCTs using standardized endpoints are required to better define the role of antidepressants in IBS.