Inflammatory bowel disease, often called IBD, is a long-term condition that causes ongoing inflammation in the digestive tract.
The two main forms are Crohn’s disease and ulcerative colitis. People with IBD often experience abdominal pain, diarrhea, tiredness and periods when symptoms suddenly become worse.
A large new study suggests that the effects of IBD may begin well before doctors make the diagnosis. Researchers found that people who later develop IBD are more likely to experience mental health problems several years before their bowel disease is identified. The findings were published in Clinical Gastroenterology and Hepatology.
The research team studied the health records of more than 40,000 people with IBD in Sweden between 2007 and 2023. Their results were compared with nearly 180,000 people from the general population and more than 26,000 brothers and sisters who did not have IBD. Comparing siblings helped reduce the influence of shared genes and childhood environment.
The results showed that the risk of psychiatric disorders started to rise two to three years before an IBD diagnosis. The risk was highest during the first six months after diagnosis, when it was about 50% higher than expected. Even 10 years later, the risk remained about 19% higher.
The increased risk was mainly linked to depression, anxiety disorders and substance misuse. Doctors also found that prescriptions for antidepressants and anti-anxiety medicines began increasing about one year before IBD was diagnosed and stayed higher for at least five years afterward.
The same pattern appeared in people with Crohn’s disease, ulcerative colitis and other forms of IBD. The highest overall risk was seen in people who developed IBD during childhood and in those with a family history of psychiatric illness.
Scientists believe several factors may explain this connection. Long-lasting inflammation may affect communication between the gut and the brain through what is known as the gut-brain axis. Living with ongoing digestive symptoms, pain, fatigue and reduced social activities may also increase emotional stress before and after diagnosis.
The researchers said these findings highlight the importance of paying attention to mental health early rather than waiting until after IBD is confirmed. Screening for depression, anxiety and other psychiatric symptoms during the first medical assessment may help patients receive support sooner.
The study cannot prove that IBD directly causes mental illness because it was observational. However, the fact that similar results were found even when comparing patients with their own siblings suggests that family background alone cannot explain the association.
This nationwide study is strengthened by its very large sample size, long follow-up and sibling comparison, which improve confidence in the findings.
However, observational research cannot establish cause and effect, and some psychiatric conditions may have gone undiagnosed. Overall, the results support integrating mental health care into routine IBD treatment from the earliest stages.
