gene was found to be decreased in whole blood samples collected six decades after stress exposure relative to their non-exposed siblings (Heijmans et al., 2008). This effect was specific to individuals that were exposed to the famine during periconception (Heijmans et al., 2008; Tobi et al., 2009). It is important to note that all of the studies examining the effects of stress on methylation in humans utilized peripheral samples, so it is unclear the extent to which the changes discussed here reflect methylation levels in the brain. However, there is evidence of abuse during childhood changing GR methylation in the brains of suicide completers (Labonte et al., 2012; McGowan et al., 2009).
