KDR and depressive symptom measurement: A recent study that evaluated the levels of proteins associated with the neuroplasticity of the cerebrospinal fluid in patients with psychiatric disorders found positive correlations between the scores of a scale that assesses symptom severity in schizophrenia and S100β levels, in addition to a positive correlation between the GRID-HAM21 scores with S100β and KDR concentrations in people with depression [58].