Sunday, January 18, 2009
News

Sick of the past

Emory study: Trauma in childhood may lead to chronic fatigue in adulthood

By Carrie Gann

For people living with chronic fatigue syndrome, everyday life is completely draining. A trip to the grocery store is exhausting. Staying focused and alert is difficult at best. A few minutes of casual conversation can wipe them out for the rest of the day. No matter how much downtime they are allowed, no amount of rest is ever enough to bring back their energy.

    The Centers for Disease Control and Prevention (CDC) estimates that between 1 million and 4 million Americans live with the debilitating symptoms of chronic fatigue syndrome (CFS), a disease marked by overwhelming exhaustion, problems with memory and concentration, and other general aches and pains that just won’t go away. But after more than 20 years of research, the causes of the disease, along with any reliable treatments, remains unclear. However, new research from scientists at Emory University School of Medicine and the CDC has shed new light on this mysterious illness.

According to the study, trauma experienced early in life may be a powerful risk factor for CFS. The results published in the Jan. 5, 2009 issue of the journal Archives of General Psychiatry showed that people who experienced physical, emotional or sexual abuse as children were six times more likely to develop the disease as adults. The connection between the two may lie in a specific biological key: cortisol, a hormone that the body uses to regulate its response to stress. Christine M. Heim, Ph.D., the lead author of the study, explains that traumatic events in childhood put an early strain on a person's production of cortisol that could permanently alter the body's regulation of stress.

"Any trauma that occurs during early development, when the brain is still very plastic could have a long-term effect on cortisol production," says Heim, an associate professor in the Department of Psychiatry and Behavioral Sciences at the Emory University School of Medicine.

Heim and her research team analyzed data from 113 Georgians with CFS and 124 without it. Of the study participants with CFS, 62 percent reported experiencing some kind of trauma in their childhood, particularly sexual abuse emotional abuse or neglect. Individuals who had post-traumatic stress disorder (PTSD) were nine times more likely to have the disease.

The findings of the study are particularly striking because they match almost exactly the findings of a 2006 study of people in Wichita, Kans. Roughly two-thirds of participants with CFS in the Wichita study also reported that they had experienced abuse or neglect as children.

However, in the Emory study, Heim and her colleagues were able to link these patterns to specific biological facts: a difference in levels of cortisol.

“We have known for a long time that trauma during early development can have a long-term effect on cortisol production," says Heim. "And low cortisol levels are a classic indicator of chronic fatigue syndrome. But no one had every investigated the link between the two. That was surprising to me because it’s such an obvious connection to make.”

When the saliva of the study participants with CFS was tested, only those reporting childhood trauma showed the low levels of cortisol that are a hallmark of the disease.

William C. Reeves, M.D., chief of the CDC’s Chronic Viral Diseases branch and a researcher on the study, explained that connecting the dots between childhood trauma and CFS using the brain’s cortisol production makes good physiological sense.

“The brain is a plastic organ, and the way your brain reacts to stress is modified over your lifetime,” Reeves says. “Early childhood events, particularly severe stressors, are very powerful moderators of that development.”

An individual who suffers from CFS is more than just a tired person. The disorder is often described as a constant feeling of exhaustion—like having the flu, but never being able to recover. Because the disease lacks traditional hallmark symptoms, it can be difficult to diagnose, particularly since no lab tests have been developed to detect it. As a result, most people don’t realize they have it.

The disease mostly affects adults in their 40s and 50s, and affects four times as many women as men. A 2004 study estimated that CFS costs $9.1 billion each year in lost productivity in the United States—about $20,000 per year in lost income for each person who suffers from the disease.

CFS’s link to child abuse indicated in the Emory study is not an uncommon one to make. The life-altering trauma caused by childhood abuse or neglect becomes a general risk factor for a laundry list of illnesses and disorders, including depression, anxiety, substance abuse, fibromyalgia, pelvic pain, irritable bowel syndrome and cardiovascular disease.  Heim points out that although these disorders are quite different, they all can be aggravated by stress.

“There might be one common mechanism that links them, and it might be emotional,” she says. “Whatever the connection, it appears that CFS also might be a part of that spectrum of disorders related to childhood trauma.”

However, Heim emphasizes that not all people who suffer from CFS have been through trauma as children.

Heim’s connection of CFS to a specific biological influence—cortisol and stress—is significant in that no previous research has identified specific physical or chemical signs or symptoms of the disease. According to Reeves, CFS is notable for its apparent ability to remain a mystery.

“It’s a difficult illness, because it’s entirely based on people’s symptoms,” he explains. “As a physician, there’s no virus that I can identify, there’s no lesion I can biopsy. We do not yet have a marker to help us diagnose and treat it.”

 Now, armed with a connection to hard facts, Heim and her team are planning more studies that will investigate the stress hormone system and how it reacts in different situations. They also will follow this study’s CFS participants in order to monitor how their illness changes over time.

The researchers behind the Emory study hope that their findings will help to steer CFS research toward a treatment for the disease. 

“We feel that it’s a very significant finding because it begins to move us toward identifying ways to treat and prevent CFS,” Reeves says. SP