Psychology and Epigenetics

Abstract

The Human Genome Project mapped the complete DNA sequence that exists in each human cell, but questions remain about how genes are expressed. Epigenetics is defined as mechanisms of gene expression that can be maintained across cell divisions, and thus the life of the organism, without changing the DNA sequence. Recent research has identified important epigenetic mechanisms that play essential roles in normal and abnormal development. Of special significance for psychology are the findings that environmental and psychosocial factors can change the epigenome. Research also suggests that some experiences and epigenetic changes of an individual can be passed down to more than one generation of descendants. Linkages between epigenetics and psychopathology are emerging that point to new possibilities for conceptualizing, preventing, and treating disorders.

Transgenerational Effects of Childhood Conditions on Third Generation Health and Education Outcomes

“…Due to its pathbreaking nature, the sequence of studies based on theÖverkalix data has evoked great interest in the biological literature (see e.g. Zeisel, 2007, Gräff and Mansuy, 2008, Masterpasqua, 2009, Francis, 2011, Low et al, 2012, and Grossniklaus et al, 2013. The authors find that low paternal grandfather's food supply in the years just before adolescence is associated with a lower mortality risk of grandsons, while low paternal grandmother's food supply is linked to a lower mortality risk of their granddaughters.…”

“…In this context, the possibility of transgenerational transmission is particularly interesting (see e.g. Harper, 2005, Gräff and Mansuy, 2008, Masterpasqua, 2009, Grossniklaus et al, 2013, Bohacek and Mansuy, 2015. Epigenetic imprinting is the phenomenon that shortly after conception, when stem cells are formed, some of the methyl tags from previous generations remain, causing heritable changes in gene functioning that are not driven by changes in the DNA sequence.…”

“…If epigenetic modifications take place on the part of the genome that is genetically imprinted, this could explain sex-specific epigenetic inheritance. "Imprinted genes" keep their methyl tags (about 1% of genes), which function as a biological marker to flag up their maternal or paternal origin (Masterpasqua, 2009). Epigenetic inheritance may thus be a biological means for humans to adapt to changing environments and to transmit environmental information to the next generation.…”

“…2 Epigenetic inheritance is the most plausible explanation for why nutritional shocks may persist across generations and one which has become a focal point in biological and epidemiological research on the long run effects of nutrition, stress and other early life circumstances (see Gräff and Mansuy, 2008, Masterpasqua, 2009, Lundborg and Stenberg, 2010, Hochberg et al, 2011, Kuzawa and Thayer, 2011, and Low et al, 2012.…”

Percussions of Epigenetics on Mood Disorders; is it really A Charm or Just A Propaganda

“…Poor care during infancy whether in human or animal studies was associated with epigenetic changes which resulted in long term impairments of neglect [19][20][21]. Interestingly; frequent liking in rats resulted in a long term decrease in stress response assessed both behaviorally and biochemically by measuring elements of the Hypothalamic Pituitary Adrenal Axis (HPA).…”