(up to age 55). The combination of widespread musculoskeletal pain, high tender point count, and non-restorative sleep are usually sufficient criteria for the diagnosis of fibromyalgia and the patients referred for this study will have been well characterized in the Fibromyalgia Clinic at Georgetown University or by the referring physician. We will, however, by history, physical examination, screening laboratory studies and examination of the patient s medical records confirm the absence of any evidence for peripheral neuropathies, entrapment syndromes, neurologic disorders or metabolic/endocrine disorders, such as untreated hypothyroidism, as well as the rheumatoid disorders that might be confused with fibromyalgia and confound the study. Patients who have abnormal screening test results or who have traumatic or non-traumatic disorders to which pain may be attributed. Also, patients who have a positive HIV result will be excluded. Subjects with obviously impaired mental capacity that precludes informed consent and ability to provide adequate self-ratings are to be excluded.