Many research studies have looked at the differences between CFS and major depressive illness and outcome data supports the fact that CFS is not the same as depression, although some people experience depression along with CFS symptoms. The diagnosis of CFS is done by excluding illnesses that present with similar symptoms, such as hypothyroidism. A thorough history and physical, including a neurological and psychological assessment and exclusionary labs are ordered. If these standard reviews and basic tests don't suggest other possible causes, CFS is a likely possibility. CFS is a multi-symptom, complex illness.
Most patients state that their illness began with flu-like symptoms that never fully improved.
The fatigue of this illness is substantial and significantly interferes with daily functioning. The 1994 International Case Definition, although designed for researchers, is loosely interpreted by clinical practitioners for diagnostic purposes. Yes, children as young as age five have been diagnosed. In addition, Dr. Bell states that since young children are often unable to verbalize what they are experiencing it is difficult to distinguish symptom patterns and many do not see themselves as being ill because they have no clear reference to normal health. He also adds that prognosis appears to be better for children.