Serum level of brain-derived neurotrophic factor in fibromyalgia syndrome correlates with depression but not anxiety

Brain-derived neurotrophic factor (BDNF) has been known to play a role in fibromyalgia syndrome (FMS) patients. Depression and anxiety are quite common additional symptoms in FMS. However the role of BDNF in these symptoms still needs to be elucidated. Although BDNF has been shown to be relevant in major depression, however studies could not show such differences between FMS patients with and without major depression. As mood-related symptom occurs frequently and differs in its intensity in FMS patients, BDNF level should be measured in subgroup regarding depression and anxiety scale. Therefore the aim of this study was to evaluate the correlation of BDNF in serum of FMS with intensity of depression and anxiety. Additionally, interleukin (IL)-6 was measured.