TOPLINE

Paediatric and young patients with inflammatory bowel disease (IBD) and concomitant attention-deficit/hyperactivity disorder (ADHD) or autism showed no difference in the risk for severe disease at 1 year after diagnosis compared with those with IBD alone. However, these patients had a lower risk for first-time hospitalisation but more hospital contacts per year than those with IBD alone.

METHODOLOGY

• Researchers conducted a nationwide registry-based cohort study to assess the effect of ADHD or autism on disease activity in paediatric and young patients with IBD.
• They included 7514 patients aged 6-24 years at IBD diagnosis from 1996 to 2022 using data from Danish national registries, of whom 785 had IBD with ADHD or autism and 6729 had IBD alone.
• Disease activity was categorised as remission, mild‐moderate disease activity, or severe disease activity.
• Severe disease activity was defined as starting or switching of advanced therapies (biologics or small molecules), undergoing IBD-related surgery (excluding perianal surgery), taking oral corticosteroids combined with an IBD-related hospital admission or visit, or requiring hospital admission for 3 or more days.
• Cumulative incidences of severe disease activity at 3-, 5-, and 10-year follow-up periods were compared between patients with IBD and comorbid ADHD or autism and those with IBD alone.

TAKEAWAY

• At 1 year, no difference in the risk for severe disease was observed between patients with IBD and ADHD or autism and those with IBD alone. At 10 years, cumulative incidences of severe disease activity were 36.2% for those with IBD and ADHD or autism and 33.7% for those with IBD alone.
• Patients with ADHD had a higher risk for severe disease later in their disease course; those with autism showed a trend towards a higher risk in the first 2 years after diagnosis. Patients younger than 18 years with IBD and ADHD or autism had a higher risk of receiving advanced therapies than those with IBD alone (adjusted hazard ratio [aHR], 1.3; 95% CI, 1.1-1.5).
• Among patients with ulcerative colitis (UC), colectomy was required in 16.3% of those with ADHD or autism and 12.4% of those with UC alone. Patients with UC and ADHD or autism who were diagnosed after 2010 had a higher risk of requiring colectomy (aHR, 1.6; 95% CI, 1.2-2.3).
• Patients with IBD and ADHD or autism had a lower risk for first-time hospitalisation than those with IBD alone (aHR, 0.8; 95% CI, 0.7-0.9) but had more total days of hospitalisation (700 vs 505 per 1000 person-years) and more annual IBD-related hospital contacts (3.7 vs 2.8 per year).

IN PRACTICE

"The diagnosis‐specific findings indicate that ADHD and autism should not be assumed to influence IBD outcomes through identical mechanisms," the authors wrote.

SOURCE

This study was led by Sabine Jansson, Department of Paediatrics and Adolescent Medicine, Hvidovre Hospital, University of Copenhagen, Copenhagen, Denmark. It was published online on September 08, 2026, in the Journal of Pediatric Gastroenterology and Nutrition.

LIMITATIONS

Patients with ADHD or autism who were diagnosed later in life by private psychiatrists might not have been reported in public records. Data on the severity of symptoms, functional impairment, difficulties during healthcare encounters, adherence to treatment, and clinical measures of IBD activity were lacking.

DISCLOSURES

This study was supported by grants from Aage og Johanne Louis-Hansens Fond, Ferring Pharmaceuticals, and Takeda Pharma A/S. Several authors declared receiving grants, travel support, or personal fees from various sources including the funding agencies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.