Genetic factors have substantial roles in neuropsychiatric disorders, but the mechanisms by which environmental factors affect the genome and contribute to depression or other mental disorders in adulthood is not well understood. A study published online in Nature Neuroscience this week helps shed some light on this process, by showing that early childhood abuse in humans can change the expression of a gene that is important for responding to stress.
Michael Meaney and colleagues found that the brains of suicide victims with a history of childhood abuse have lower levels of mRNA for the glucocorticoid receptor, which is critical for the stress response pathway, than suicide victims without a history of childhood abuse. They also found that in these patients, the glucocorticoid receptor gene had been modified to limit the amount of mRNA, and therefore functional protein that could be made. Early childhood experience has been shown to cause long-term genetic changes in the stress response pathway in rats, but this is the first evidence that the same thing happens in humans.
This study suggests one way in which childhood abuse could have long term effects on victims' responses to stress in adulthood.
Michael Meaney (Douglas Mental Health University Institute, McGill University, Canada)
Abstract available online.
(C) Nature Neuroscience press release.
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