Comorbid Illness in Women With Chronic Fatigue Syndrome: A Test of the Single Syndrome Hypothesis

Abstract

The prevalence of comorbid illness in the present CFS sample and the failure to find widespread differences in symptom severity can be seen as support for the single syndrome hypothesis. On the other hand, the existence of discrete syndromes could not be ruled out because of reliable differences between CFS and CFS/FM. Increasing comorbidity was associated with a corresponding increase in risk of major depression.