Psychological stress can increase the risk of a wide range of negative health outcomes. Studies have been completed to determine if DNA methylation changes occur in the human brain because of stress and are associated with long-term effects and disease, but results have been inconsistent. Human candidate gene studies (150) and epigenome-wide association studies (67) were systematically evaluated to assess how DNA methylation is impacted by stress during the prenatal period, early childhood and adulthood. The association between DNA methylation of NR3C1 exon 1F and child maltreatment and early life adversity was well demonstrated, but other genes did not exhibit a clear association. The reproducibility of individual CpG sites in epigenome-wide association studies was also poor. However, biological pathways, including stress response, brain development and immunity, have been consistently identified across different stressors throughout the life span. Future studies would benefit from the increased sample size, longitudinal design, standardized methodology, optimal quality control, and improved statistical procedures.
Keywords: DNA methylation; adulthood; chronic; early life; prenatal; psychological stress; reproducibility; specificity.
Mental stress can increase the risk of a wide range of negative health results. Previous studies have been carried out to explore the epigenetic (related to changes in genes) effect of different types of mental stress. The authors reviewed the literature to look at consistencies in the results of these studies. With the exception of the first exon of NR3C1, the authors found few consistent findings in epigenetic changes related to stress with regard to DNA methylation at individual CpG islands but identified some important biological systems (stress response, brain development and immunity) related to psychological stress. Bioinformatics analysis showed that different types of psychological stress affect different biological systems. The epigenetic mechanism of these systems may control the effects of mental stress on health.