Could medicines used for depression also treat chronic, severe indigestion? Scientists at Mayo Clinic suspect they can and, backed by funding from the National Institutes of Health (NIH), they are testing that premise in a nationwide clinical trial.
"Nerve cells are found throughout the body, and just as their dysfunction in the brain can cause depression, we suspect overly sensitive nerves in the gut can produce this very uncomfortable indigestion," says Nicholas Talley, M.D., Ph.D., chair of the trial and chair of the Department of Internal Medicine at the Mayo Clinic campus in Florida.
The study, which will include 400 adult men and women who have been diagnosed with functional dyspepsia, is being offered at all three Mayo Clinic campuses (Florida, Minnesota, and Arizona) and at Northwestern University, Saint Louis University School of Medicine, Dartmouth-Hitchcock Medical Center, and Baylor College of Medicine. Trial participants will be treated for three months with one of two different types of Food and Drug Administration (FDA)-approved antidepressant medications or with an inert placebo pill.
Functional dyspepsia is believed to be very common but is often confused with other gut maladies, such as acid reflux (also known as gastroesophageal reflux disease or GERD) and irritable bowel syndrome, Dr. Talley says. "The classic symptom of dyspepsia is a feeling of uncomfortable fullness after eating. A person feels bloated right away, and can experience cramping or gas," he says. "Often a person can't finish a meal because of these symptoms. It doesn't always happen with every meal, but during most of them."
The NIH recently expanded the scope of the clinical trial, which is known as the Functional Dyspepsia Treatment Trial (FDTT). It will now include four times as many patients (over 100 patients are in the study now), will run for three more years, and will receive an additional $1.2 million in federal support. "The NIH and the researchers involved in this clinical trial are very hopeful that results of this important study might, someday, help a lot of people who suffer from this disorder," Dr. Talley says.
For many patients who have functional dyspepsia, antacids (such as Rolaids) and acid-suppressing medications (like Zantac) don't work, nor does so-called proton pump inhibitors such as Prilosec, Dr. Talley says. That's because symptoms of the disorder are thought to result from abnormal muscle activity within the stomach, which may be caused by abnormal sensitivity of the nerves in the stomach or irregular signals from the brain to the muscles in the gut, he says.