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Study: CDC’s New Research Definition For CFS Flawed


(By Craig Maupin for

Since the adoption of the name “fatigue syndrome” in 1987 by a panel of scientists, the concept of Chronic Fatigue Syndrome (CFS) has undergone an evolution.   In 1988, estimates of CFS were placed at about 100,000 sufferers in the United States. After the implementation of a revised case definition in 1994, epidemiological estimates of CFS ballooned to one million sufferers in the United States.   In 2005, concerns that previous research definitions for chronic fatigue syndrome were too specific yielded yet another revision.   Today, it is estimated that almost three percent of Americans now meet the CDC’s new definition for “chronic fatigue syndrome”.

According to the authors of a new study, published in the October 2008 issue of Journal of Disability Studies, revisions to research definition could have “detrimental consequences…for people with CFS”.   The study looked at people with a diagnosis of major depressive disorder and CFS.    According to the researchers, led by Depaul University's Dr. Leonard Jason, roughly four out of ten of the people diagnosed with with major depressive disorder now meet the new research definition for CFS.   The authors conclude that the inclusion of "patients with a primary psychiatric illness in the current CFS case definition could confound the interpretation of epidemiologic and treatment studies”.

The results of the study conflict with claims from researchers at the Centers for Disease Control who say that the broader definition more accurately identifies people with CFS. According to Dr. William Reeves, who heads the CDC’s CFS research efforts, a predominantly women’s illness like CFS will benefit from the respect garnered by an integrative approach.  Reeves believes the inclusion of various psychiatric illnesses in his research samples can, at times, lead to a more accurate concept of CFS.  Reeves has used the increased estimates of CFS to plead for new funds and attention for illness, which he alleges is a severe and disabling biologically-based disease.

Whatever the outcome of the new research definition for CFS, the view that broadening definitions for CFS are changing the concept of CFS seems to be universally-accepted. The authors of the study state that a more reliable definition for CFS should be more specific, emphasizing the clinically unique features of the illness, such as sudden onset, flu-like symptoms, and prolonged fatigue after exertion. They warn that the efforts to loosen the definition of CFS will have wide-ranging impacts "on CFS epidemiologic findings, on rates of psychiatric comorbidity, on how patients are treated, and ultimately on the likelihood of finding biological markers for this illness”.