In some diseases, the underlying processes can start years before a diagnosis is made. A new study finds that people who later develop multiple sclerosis (MS) are more likely to have conditions like depression, constipation and urinary tract infections five years before their MS diagnosis than people who do not develop MS. The study, which is published in the December 5, 2023, online issue of Neurology^®, the medical journal of the American Academy of Neurology, also found that sexual problems and bladder infections, or cystitis, are more likely in people who later develop MS.

The conditions were also more likely to occur in people who had other autoimmune diseases, lupus and Crohn’s disease.

“Knowing that these conditions may be prodromal symptoms or even early-stage symptoms of MS would not necessarily lead to earlier diagnosis of the disease in the general population, since these conditions are common and could also be signs of other diseases, but this information could be helpful for people who are at a higher risk of developing MS, such as people with a family history of the disease or those who show signs of MS on brain scans but do not have any symptoms of the disease,” said study author Celine Louapre, MD, PhD, of Sorbonne University in Paris, France.

The study involved 20,174 people newly diagnosed with MS. They were each matched with three people who did not have MS of the same age and sex, for a total of 54,790 people. Then the people with MS were also compared to 30,477 people with Crohn’s disease and 7,337 people with lupus. MS, Crohn’s disease and lupus are all autoimmune diseases. They all affect women more often than men and affect young adults.

Then researchers used the medical records database to see whether the participants had any of 113 diseases and symptoms in the five years before and after their diagnosis, or before that matching date for the people who did not have an autoimmune disease.

The people with MS were 22% more likely to have depression five years before their diagnosis than the people without MS. They were 50% more likely to have constipation, 38% more likely to have urinary tract infections, 47% more likely to have sexual problems, and 21% more likely to have cystitis, or bladder infections.

For depression, 14% of the people with MS had prescriptions for antidepressants five years before diagnosis, compared to 10% of the people who did not have MS. By five years after diagnosis, 37% of people with MS had antidepressant prescriptions, compared to 19% of those without MS.

“Of course, not everyone who has these symptoms will go on to develop MS,” Louapre said. “We’re hoping that eventually these early signs will help us understand the biological mechanisms that occur in the body before the actual symptoms of the disease develop.”

A limitation of the study was that data was not available for other factors that could influence people’s risk of developing MS, such as education level, ethnicity and socioeconomic status.