Is there a metabolic basis for the fibrositis syndrome?

Patients with the fibrositis syndrome experience moderately severe musculoskeletal discomfort, mood changes associated with nonrestorative sleep, and tenderness to palpation at specific body sites. There is no characteristic abnormal laboratory finding in these patients to help identify the population. A report by Moldofsky and Warsh (Pain 1978; 5: 65-71) of low serum levels of free tryptophan in patients with severe fibrositis syndrome is intriguing but remains unexplained. Those data plus the observation by Hudson et al (Am J Psychiatry 1985; 142: 441-446; Biol Psychiatry 1984; 19: 1489-1493) that patients with fibrositis syndrome exhibit an increased prevalence of anxiety and depression suggest a number of possible avenues for further study. They include potential alterations in the homeostasis of catecholamines, corticosteroids, serotonin, aromatic amino acids, platelet membrane receptor levels, and the activity of platelet membrane monoamine oxidase. Among these possibilities, evidence is now available that suggests an increased production of catecholamines in fibrositis syndrome.