Published online Nov 14, 2020. doi: 10.3748/wjg.v26.i42.6626
Peer-review started: April 6, 2020
First decision: April 26, 2020
Revised: July 3, 2020
Accepted: September 28, 2020
Article in press: September 28, 2020
Published online: November 14, 2020
Although the association of attention deficit hyperactivity disorder (ADHD) with psychiatric disorders is well known, its association with somatic diseases is unclear. Only few studies have investigated the gastrointestinal (GI) morbidity in adult patients with ADHD.
To measure gastrointestinal comorbidity and its burden on healthcare in young adults with ADHD.
The cohort included subjects aged 17-35 years recruited to the Israel Defense Forces in 2007-2013, 33380 with ADHD and 355652 without (controls). The groups were compared for functional and inflammatory conditions of the gastrointestinal tract and clinic and specialist visits for gastrointestinal symptoms/disease during service (to 2016). Findings were analyzed by generalized linear models adjusted for background variables.
Compared to controls, the ADHD group had more diagnoses of functional gastrointestinal disorders (referred to as FGID), namely, dyspepsia [odds ratio (OR): 1.48, 95% confidence interval (CI): 1.40-1.57, P < 0.001], chronic constipation (OR: 1.64, 95%CI: 1.48-1.81, P < 0.001), and irritable bowel syndrome (OR: 1.67, 95%CI: 1.56-1.80, P < 0.001) but not of organic disorders (inflammatory bowel disease, celiac disease). They had more frequent primary care visits for gastrointestinal symptoms [rate ratio (RR): 1.25, 95%CI: 1.24-1.26, P < 0.001] and referrals to gastrointestinal specialists (RR: 1.96, 95%CI: 1.88-2.03, P < 0.001) and more episodes of recurrent gastrointestinal symptoms (RR: 1.29, 95%CI: 1.21-1.38, P < 0.001). Methylphenidate use increased the risk of dyspepsia (OR: 1.49, 95%CI: 1.28-1.73, P < 0.001) and constipation (OR: 1.42, 95%CI: 1.09-1.84, P = 0.009).
ADHD in young adults is associated with an excess of FGID and increased use of related health services. Research is needed to determine if an integrative approach treating both conditions will benefit these patients and cut costs.
Core Tip: The association of attention deficit hyperactivity disorder (ADHD) with gastrointestinal morbidity and gastrointestinal-associated healthcare burden is unclear. We measured it on a large cohort of young adults, containing 33380 subjects with ADHD and 355652 without. We showed for the first time that ADHD is associated with dyspepsia, chronic constipation, and irritable bowel syndrome but not with inflammatory bowel disease and celiac disease. Furthermore, young adults with ADHD have more frequent primary care visits for gastrointestinal symptoms and referrals to gastrointestinal specialists. ADHD in young adults is associated with an excess of functional gastrointestinal disorders and increased use of related health services.