Consensus paper of the WFSBP Task Force on Biological Markers: Biological Markers in Depression

Abstract

Biological markers for depression are of great interest to aid in elucidating the causes of major depression. We assess currently available biological markers to query their validity for aiding in the diagnosis of major depression. We specifically focus on neurotrophic factors, serotonergic markers, biochemical markers, immunological markers, neuroimaging, neurophysiological findings, and neuropsychological markers. We delineate the most robust biological markers of major depression. These include decreased platelet imipramine binding, decreased 5-HT1A receptor expression, increase of soluble interleukin-2 receptor and interleukin-6 in serum, decreased brain-derived neurotrophic factor in serum, hypocholesterolemia, low blood folate levels, and impaired suppression of the dexamethasone suppression test. To date, however, none of these markers are sufficiently specific to contribute to the diagnosis of major depression. Thus, with regard to new diagnostic manuals such as DSM-V and ICD-11 which are currently assessing whether biological markers may be included in diagnostic criteria, no biological markers for major depression are currently available for inclusion in the diagnostic criteria.

Application of fatty acid and lipid measurements in neuropsychiatry

“…Lipid biomarkers are considered for diagnostics and for evaluation of the effectiveness of antidepressant drug [25]. Recent evidence has suggested an important role of lipids in the aetiology and treatment of depression [48,49].…”

“…The biological relationship of mental disorders and the "stress response" involves a series of complex, interactive neurophysiological reactions in the brain, the autonomic nervous system, adrenocortical (HPA) axis, immune system and platelet adhesion [24]. The neurochemical system mediating the stress response becomes more "sensitive" to future stressors related to the original experience [25]. Dysregulated lipid metabolism may be of particular importance for central nervous system (CNS) injures and disorders as the CNS has the highest lipid concentration next to adipose tissue [26].…”

Assessment of Brain Monoaminergic Signaling Through Mathematical Modeling of Skin Conductance Response

“…The search for biological correlates (biomarkers) of neurochemical processes associated with mental disorders has not yet resulted in convincing and applicable findings (Bartova et al, 2010;Mössner et al, 2007). A reason that may account for the fail could be that attempts that have been made had been focused on a single neurotransmitter activity (Mössner et al, 2007).…”

“…A reason that may account for the fail could be that attempts that have been made had been focused on a single neurotransmitter activity (Mössner et al, 2007). On the other hand, "Models which postulate too little or too much of a single neurotransmitter are not consistent with the complex regulation of neurotransmitter systems… There are major functional interactions among different neurotransmitter and neuropeptide systems which make single neurotransmitter theories simplisti A task for future investigations… is to develop clinically applicable biological tests that can assess the functional interactions among different neurotransmitter and neuropeptide systems and specific brain structures.…”

Increased Cortisol Levels in Depression: A Comparative Study Evaluating the Correlation of Hypercortisolemia with Prosocial Coping Mechanisms

“…Among proposed markers for depression we can mention: hypercholesterolemia and impaired suppression of the dexamethasone suppression test, decreased 5-HT1A receptor expression, increase of soluble interleukin-2 receptor and interleukin-6 in serum, decreased brain-derived neurotrophic factor (BDNF) in serum and low blood folate levels [14].…”