Biochemical markers of depressive disorders – a new concept of the diagnostic significance of its response to acute stress
Med Sci Tech 2012; 53(1): RP47-52
Many authors have commented on the clinical need for objective markers of the existence of severe depressive episodes. They point out that, although thus far no single factor has been discovered that can be used as a reliable marker, many features have been recognized that may play a role in such indicators as long as they are combined in a multivariate panel of indices.
Elevated levels of certain biochemical substances and specific characteristics of gene polymorphisms have been recognized as signs of major depression. Also, there are characteristic changes recognized by methods of structural and functional brain imaging, especially the so-called parameters of functional connectivity in the brain.
In this paper I review the biochemical substances that can act as markers of severe depression and discuss the importance of biochemical substances that are indicators of inflammation (eg, CRP, TNF and proinflammatory cytokines). I also discuss the importance of manifestations of oxidative stress and the role of BDNF.
I propose an original hypothesis stating that in attempting to differentiate major depression from mood disorders induced by existential events, an efficient biomarker of severe depression may be the altered behavior of the concentrations of these substances after a suicide attempt.
Keywords: major depression, brain-derived neurotrophic factor (BDNF), biochemical diagnostics, proinflammatory cytokines, major depressive disorder (MDD), biochemical signs of severe depression