Research just published in the "International Journal of Psychophysiology" determined that, using independent criteria, CFS can be distinguished from depression--two disorders that share many of the same symptoms.
CFS is an often debilitating disorder, characterized by a constellation of symptoms including fever, sore throat, headache, muscle weakness, myalgias, post-external malaise, sleep and cognitive disturbances. The level of disability varies for people with CFS, but some individuals find they are unable to return to work or function normally on a day-to-day basis. Unfortunately, many of these symptoms are subjective in nature and are difficult to quantify or confirm, says Hannah Pazderka-Robinson, the lead author on the study. Not only does the stigma attached with the disorder play an emotional toll on the patient, but it has implications for insurance claims as well.
"There are a number of medical professionals who don't believe that CFS exists in the first place," said Pazderka-Robinson. "The problem is, both CFS and depression are characterized by very similar profiles. Imagine a patient who approaches a doctor and tells him they feel depressed and tired all the time.
"Since depression shows a high co-morbidity with CFS, some CFS patients are often given antidepressants--that don't work or work poorly, since they do not address the underlying condition. Again, when these medications don't work, physicians sometimes jump to the conclusion that there isn't really anything, physically, wrong. Obviously, both misdiagnosis and the tendency for doctors to treat these patients as if they're not really sick can be extremely distressing. It can also undermine the patient's trust in the doctor and make them less likely to seek treatment if the condition worsens."
The most significant part of the research was to provide independent verification for CFS sufferers that these patients are different than normal controls and they're not "just depressed," said Pazderka-Robinson.
Numerous psychological investigations have attempted to differentiate these groups, with limited success. The U of A study was the first of its kind to use electrodermal activity--electrodes were placed on each hand--to investigate the differences among CFS, depression patients and healthy controls. Using tone and light stimuli, the results showed that CFS can be discriminated from those with major depression by recordings of skin temperatures and electrodermal activity.
Moreover, the profile of CFS patients is clearly different from normal controls, suggesting there is a clear biological basis to the condition.
Pazderka-Robinson completed this study with researchers from the University Centre for Neuroscience at the University of Alberta and from Alberta Hospital.