In light of our previous observation of higher levels of cerebrospinal fluid 
(CSF) amyloid beta-42 (Abeta42) and CSF/serum albumin ratio in major depressive 
disorder (MDD), we analyzed two additional CSF biomarkers reflecting 
neurodegeneration-neurofilament protein light (NFL) and glial fibrillary acidic 
protein (GFAp)-in relationship to prevalent geriatric depression. 
Neuropsychiatric, physical, and lumbar puncture examinations, with 
DSM-III-R-based depression diagnoses and measurement of CSF levels of NFL and 
GFAp, were evaluated among a population-based sample of 78 elderly women (mean 
age, 73.9+/-3.2 years) without dementia for at least 10 years after CSF 
collection. Eleven (13.1%) women had MDD, and higher levels of NFL compared with 
women without depression. A multivariate model including age, NFL, Abeta42 and 
the CSF/serum albumin ratio showed that each biomarker was independently and 
positively associated with MDD, and that this biomarker profile explained more 
variation in the model compared with single or combined biomarkers. A CSF 
profile with higher levels of NFL, Abeta42, and CSF/serum albumin ratio may 
indicate neuropathological and vascular events in depression etiology. This 
contrasts with the well-characterized pattern of low Abeta42, higher CSF/serum 
albumin ratio, and higher NFL in Alzheimer's disease.