Stress is considered to be a predisposing factor to psychiatric disorders and has been associated with decreased neurogenesis and reduced hippocampal volume especially in depression. In white blood cells, chronic psychological stress has been associated with telomere shortening. The authors hypothesized that in psychiatric disorders, stress-driven accelerated cellular aging may be observed in brain regions particularly sensitive to stress. Telomere length was measured by quantitative-PCR in five brain regions (dorsolateral prefrontal cortex, hippocampus, amygdala, nucleus accumbens and substantia nigra) in major depressive disorder, bipolar disorder, schizophrenia and normal controls.
The study found significant differences in telomere length across brain regions suggesting variable levels of cell aging, with substantia nigra and hippocampus having the longest telomeres and the dorsolateral prefrontal cortex the shortest. A significant decrease in telomere length was observed specifically in the hippocampus of major depressive disorder subjects; several genes involved in neuroprotection and in stress response (FKBP5, CRH) also showed altered levels of mRNA in the hippocampus of these individuals. The authors suggest the presence of hippocampal stress-mediated accelerated cellular aging in depression.
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Mamdani F, Rollins B, Morgan L, Myers RM, Barchas JD, Schatzberg AF, Watson SJ, Akil H, Potkin SG, Bunney WE, Vawter MP and Sequeira PA: Variable telomere length across post-mortem human brain regions and specific reduction in the hippocampus of major depressive disorder. Transl. Psychiatry 5:e636. doi: 10.1038/tp.2015.134 (2015).
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http://www.ncbi.nlm.nih.gov/pubmed/26371764