Shlomo Yehuda and David I. Mostofsky The Second Farber Center International Conference was held on December 19th, 1995 at Bar Han University. Israel. The topic of the conference was: "Chronic Fatigue Syndrome. " The members of the Scientific Committee were: Prof. Yehuda. Prof. Mostofsky, Mr. Riesenberg, and Prof. Sredni. This conference was supported by the Farber Center for Alzheimer Research. the Ginsburg Chair for Re search into Alzheimer Disease, and by the Gold Founda tion. The present volume summarizes the controversial and interesting issues as well as the experimental and re search results as discussed by the distingUished invited speakers. The term "chronic fatigue syndrome" was created to describe a group of symptoms that has often been popu larly referred to as the "yuppie flu. " The unusual and puz zling symptoms of CFS include severe fatigue, weakness, fever, depression. and sore throat and lymph nodes. Sev eral other disorders seem to share many of the CFS's symptoms to various degrees and since no undisputed bio logical etiology has been identified, it has often been re garded with great suspicion as a legitimate and organic disorder. Only in cases of infectious mononucleosis ("kiss ing disease") was the Epstein-Barr herpes virus found. The controversy among physicians and other health care pro fessionals concerns the very existence of CFS as a unique 5 6 Preface entity well differentiated from other terms such as fibromy algia. neurasthenia. or special kinds of depression. (For examples. see: Goldenberg, 1990; Millenson.