Researchers in the U.K. report that non-restorative sleep is the strongest, independent predictor of widespread pain onset among adults over the age of 50. According to the study published in Arthritis & Rheumatology (formerly Arthritis & Rheumatism), a journal of the American College of Rheumatology (ACR), anxiety, memory impairment, and poor physical health among older adults may also increase the risk of developing widespread pain.