6. For 2 weeks prior to MRI and diagnostic visit, unable to be free of centrally active medications or treatment methods. These include medications commonly used to treat pain (eg, antidepressants, muscle relaxants, centrallyacting analgesics), as well as transcutaneous electrical nerve stimulation, biofeedback, tender and trigger point injections, acupuncture, and anesthetic or narcotic patches. PRN doses of short acting medications, e.g. acetaminophen, aspirin, and nonsteroidal antiinflammatory agents will be allowed for pain with usage carefully monitored, but patients must be willing to be off of these medications for 24 hours prior to the major evaluations at intake and MRI study visit. Stable doses of non-benzodiazepines will be allowed for sleep (but not tricyclics)