Research in fibromyalgia: past, present and future.

Research in regard to fibromyalgia has greatly increased during the last 5 years. Initially, investigators concentrated on clinical descriptions and diagnostic criteria. Early pathophysiologic aspects studied included sleep disturbances and psychiatric aspects of the syndrome. More recently, studies have focused on peripheral tissue abnormalities, including sophisticated studies of abnormal muscle metabolism, immunologic and neurotransmitter abnormalities. Future suggested research directions are reviewed.