Depression Biomarkers: Which Ones Matter Most?
Multiple biomarkers of depression involved in several brain circuits are altered in patients with unipolar depression. The first comprehensive meta-analysis of all biomarkers quantified to date in cerebrospinal fluid (CSF) of individuals with unipolar depression showed that several could be "clinically meaningful" because they suggest neuroimmunological alterations, disturbances in the blood-brain barrier, hyperactivity in the hypothalamic-pituitary-adrenal (HPA) axis, and impaired neuroplasticity as factors in depression pathophysiology.
@nancy The systematic review and meta-analysis included 97 studies investigating 165 CSF biomarkers. Of the 42 biomarkers investigated in at least two studies, patients with unipolar depression had higher CSF levels of interleukin 6, a marker of chronic inflammation; total protein, which signals blood-brain barrier dysfunction and increased permeability; and cortisol, which is linked to psychological stress, compared with healthy controls.