Physical and psychological considerations in the classification of fibromyalgia.

Several existing techniques for diagnosing psychiatric illness in the presence of physical complaints are faulty. Psychiatric illness may affect only as few as 30% of patients with fibromyalgia in some series. Selection bias overemphasizes the contribution of psychiatric illness to fibromyalgic. Much of that illness will be secondary to pain and disability. Some fibromyalgia disturbances can arise through insomnia and anxiety. Principles in the classification of fibromyalgia are discussed.