Gray matter loss in brain

Yet Another Study Showing Decreased Gray Matter in the Brains of Fibromyalgia Patients
http://fibroresearch.blogspot.com/2009/05/yet-another-study-showing-decreased.html

The finds of decreased gray matter in brains always feel terrifying to me. But which one comes first? Continuous stress alters brain; what about continuous, intolerable pain? Do the alterations come first, and cause the pain, or do we have those gray matter losses because we have pain that goes beyond words more often than not? Means, would a more effective treatment (what, I don't know) reduce the gray matter loss? And how to live with the loss?