There have been a number of advances in the etiology of the chronic and widespread pain that is the hallmark of fibromyalgia: We learn more and more about the interplay of both physiological and psychological factors; but predicting the onset of such pain remains problematic, even with evidence for a genetic predisposition to the development of chronic pain. (There is data showing that first-degree relatives of patients with fibromyalgia are 8 times more likely to have fibromyalgia.)
The serotoninergic system plays an anti-pain role, and abnormalities in this system have been observed in patients with fibromyalgia. Still, it is uncertain whether this system is directly related to chronic widespread pain, as opposed to the reactive depression associated with being afflicted with chronic widespread pain. For this reason, researchers have tried to find a link between genes in the serotonin pathway and fibromyalgia.
An article in the March, 2011 edition of "Arthritis & Rheumatism" described the first study to explore the genetic susceptibility to both chronic widespread pain and the extent of musculoskeletal pain. Indeed, there were associations of genetic material known as single-nucleotide polymorphism (SNP) with musculoskeletal pain, namely in TPH2 and HTR2A. Another SNP, rs6313, has been shown to be associated with depression and chronic fatigue syndrome, another disorder associated with chronic widespread pain.