Why this study matters

It is well-known that < 40% and 60% of depressed patients have remission of symptoms with the first and second medications prescribed, respectively, which may be explained by the multifactorial pathogenesis underlying depression and the complex neurocircuitry involved.

Study design

A meta-analysis of 97 published studies involving CSF biomarkers in patients > 18 years of age was undertaken using the PRISMA and MOOSE reporting guidelines.

Results and conclusion

Of 165 CSF biomarkers evaluated, the CSF levels of IL-6, total protein, and cortisol were increased, while the CSF levels of homovanillic acid, γ-aminobutyric acid, somatostatin, brain-derived neurotrophic factor, amyloid-β 40, and transthyretin were lower in patients with unipolar depression compared to healthy controls.