The Associations Between Attention-Deficit/Hyperactivity Disorder Stimulant Medications and Irritable Bowel Syndrome

Irritable Bowel Syndrome (IBS) is a disorder of gut-brain interaction affecting 11% of the global population. Patients with Attention-Deficit/Hyperactivity Disorder (ADHD) have increased odds of IBS, but this may be confounded by stimulant use. The present study examined the association between ADHD and subsequent IBS, comparing ADHD patients treated with stimulants to those who were unmedicated.

This retrospective cohort study used the TriNetX U.S. Collaborative Network, a multi-institutional electronic health record platform with de-identified data from 117 million patients across 71 U.S. healthcare organizations. Adults with ADHD were divided into those who had ever received stimulants ("stimulant cohort") or never received ADHD medications ("control cohort"). The primary outcome was a diagnostic record of IBS any time after the index event. IBS with Constipation (IBS-C), IBS with Diarrhea, and mixed IBS were assessed separately. Cohorts were propensity score matched for demographics, comorbidities, and behavioral factors. Odds ratios (OR) with 95% confidence intervals (CI) were calculated.

In the stimulant cohort, 2,104 of 112,832 patients (1.9%) received an IBS diagnosis versus 2,333 of 112,506 patients (2.1%) in the control cohort. Stimulant exposure was associated with a 10.3% decreased risk of any IBS (OR, 0.90; 95% CI, 0.85-0.95) and a 14.1% decreased risk for IBS-C (OR, 0.86; 95% CI, 0.74-0.99).

Stimulant exposure was associated with a decreased risk of IBS and IBS-C. This supports the view among ADHD researchers that stimulants are effective and low-risk treatments. Future studies using longitudinal or prospective data are needed to validate these findings.