Stress and Ulcers — Just a Myth?

"You'd better relax — you're going to get an ulcer!"

Common wisdom holds that ulcers are caused by stress, and until recently, so did medical wisdom. The medical picture changed in the mid-1990s when the National Institutes of Health concluded at a major conference that most ulcers are caused by a bacterium called Heliobacter pylori (H. pylori) and should be treated with antibiotics.

Although the first antibiotic for treating peptic ulcer disease was approved in 1996, many patients and doctors remained unaware that most cases are caused by infection. In an attempt to educate the public and the medical community, government and professional associations launched extensive educational campaigns. The message was simple: ulcers are caused by infection, not by stress or spicy food.

But the pendulum may have swung too far, according to recent research. While it's true that many peptic ulcers are caused by H. pylori infection, many are not. And, only about 20 percent of those who are infected with H. pylori ever develop ulcers. So while recognizing that the bacterium is definitely a big part of the picture, researchers are turning again to look at the role of psychological factors, especially stress.

"Evidence linking psychosocial stress to peptic ulcer is too strong to be ignored," states Dr. Susan Levenstein of the San Camillo-Forlanini Hospital in Rome, Italy. "Psychosocial factors can be estimated to contribute to 30 percent to 65 percent of ulcers."

In a recent issue of Psychosomatic Medicine, Levenstein explains that although many of the studies linking ulcers to stress were poorly done, there are still many that weren't. Important among these are prospective studies that follow a group of people for a period of time to see what factors at the beginning of the study predict later development of ulcers.

These studies report that psychosocial factors such as stress, depression, trauma, job frustration and family difficulties all predict later development of ulcers. Other studies have shown that these factors slow the healing of ulcers. One problem, Levenstein points out, is that some other influence could be causing both stress and ulcers — socioeconomic status or medical conditions, for example.

But even when these factors are accounted for, it appears that stress plays an important role in at least some cases of ulcer. In an Australian study, for example, 44 percent of patients recently diagnosed with duodenal ulcers reported experiencing severe and often chronic stress during the previous six months. Among a comparison group of healthy subjects matched for age, gender and socioeconomic status, only nine percent reported such stress.

Levenstein points out that stress can contribute to the development of ulcers without actually causing them. For example, stress can influence health behaviors such as smoking, drinking and poor eating and sleeping habits — all of which are established risk factors for peptic ulcer. Research also suggests that people who feel stressed are more likely to take medications called non-steroidal anti-inflammatory drugs, or NSAIDs, such as aspirin, ibuprofen, naproxen and a number of prescription medications. These drugs definitely can cause ulcers; this is actually one of their most serious side effects.

But even after accounting for these stress-related health behaviors, says Levenstein, stress itself remains a risk factor for ulcers. A nine-year study in California found that participants with high levels of stress were more than twice as likely to develop ulcers than those without stress, even after accounting for smoking, drinking, eating and sleeping habits.

There are several ways that psychosocial factors might contribute to ulcers, explains Levenstein. Emotional distress and severe stress (as some mood and personality disorders) are significantly associated with increased production of acid in the stomach and small intestine. These psychosocial factors can also affect the body's immune system and hormone balances, impairing its ability to heal.

According to Levenstein, about 20 percent of ulcers appear to be unrelated to either H. pylori infection or taking NSAIDs — the two major causes. Recent studies report that only one-half to two-thirds of ulcer cases involve bacterial infection. Levenstein suggests that in some cases, individuals may be physiologically predisposed to develop ulcers, and the effects of psychosocial stress in the body activate this tendency. In fact, she suggests, some ulcer cases in which H. pylori is found may not actually be caused by the bacterium.

The bottom line, says Levenstein, is to look at peptic ulcers the way we look at cardiovascular disease: as a complex condition that's influenced by a variety of genetic, physiological and psychosocial factors.

"Stress and heliobacter may be two independent risk factors with additive effects, just as diabetes and smoking carry additive risks for coronary artery disease," the researcher suggests. "[Some] ulcers may be destined to develop regardless of the individual's psychological characteristics, but there is some evidence that light infections may be helped to evolve into ulcers by psychosocial factors."

As both the general population and the medical community turns to more complex explanations of diseases from heart attack to the common cold, we can expect to see more and more research showing that psychosocial and physiological forces interact in human disease.