ALBERT

Description: Major depressive disorder (MDD) presumably includes heterogeneous subgroups with differing pathologies. To obtain a marker reflecting such a subgroup, we analyzed the cerebrospinal fluid (CSF) levels of fibrinogen, which has been reported to be elevated in the plasma of patients with MDD. Three fibrinogen-related proteins were measured using aptamer-based analyses and CSF samples of 30 patients with MDD and 30 controls. The numbers of patients with an excessively high level (〉99 percentile of the controls) was significantly increased (17 to 23%). Measurement reproducibility of these results was confirmed by an ELISA for fibrinogen (Pearson’s r = 0.77). In an independent sample set from 36 patients and 30 controls, using the ELISA, results were similar (22%). When these two sample sets were combined, the number of patients with a high fibrinogen level was significantly increased (15/66; odds ratio 8.53; 95% confidence interval 1.9–39.1, p = 0.0011). By using diffusion tensor imaging, we found white matter tracts abnormalities in patients with a high fibrinogen level but not those patients with a normal fibrinogen level, compared with controls. Plasma fibrinogen levels were similar among the diagnostic groups. Our results point to a subgroup of MDD represented by increased CSF fibrinogen and white matter tract abnormalities. Scientific Reports 5 doi: 10.1038/srep11412