Al-Nimer MSM, et al. - In this case-control study, researchers involved 35 healthy women (Group I) served as controls and 130 women with newly diagnosed fibromyalgia (FM) (Group II) to evaluate the serum serotonin levels in the newly diagnosed FM and to relate these levels to the presenting signs and symptoms. Significant low-serum serotonin levels observed in newly diagnosed FM women, which does not correlate with a significant increment of the platelet activity expressed as increased mean platelet volume (MPV) and platelet width distribution percentage. The study findings proposed that the correction of serum serotonin level through medicines could help the patients.