Abstract
The present study is a follow-up of the research conducted by Jason, Fennell et al. (1995,1999, 2000) on a multistage theory for chronic fatigue syndrome (CFS). This multistage model is a very promising method for the evaluation of patients suffering from CFS and could facilitate the appropriate selection of various psychosocial therapies that improve the patient's ability to cope with their illness. Four predictive factors emerged with moderate to excellent reliability. A Spearman's rank correlation revealed positive correlations between our four-factor model and the three-factor model identified by Jason et al. (1999). A correlation matrix between the dimensional psychological investigation and the Fennell Phases revealed characteristics as suggested by previous research. Biological parameters varied over the different phases suggesting an important interaction between body and psyche.