Childhood trauma burns into the genome
Traumatic experiences in childhood, such as violence, abuse or tragic deaths, result in a significantly increased risk of mental illness later in life. An international team of researchers led by Elisabeth Binder from the Max Planck Institute for Psychiatry in Munich has now been able to decipher a molecular effect that causes this increased susceptibility to mental illness.
According to the researchers, the traumas in childhood and the associated high stress lead to permanent changes in the regulation of genes. "Some variants of the FKBP5 gene are epigenetically changed by early trauma", which "causes permanent malregulation of the stress hormone system in people with this genetic predisposition," reports the Max Planck Institute for Psychiatry in a current press release. The scientists have published the results of their investigations in the journal "Nature Neuroscience".
Life-long impairments due to traumatic childhood experiences The abuse and experiences of violence in childhood that can affect those affected for a lifetime has long been known. The increased susceptibility to mental illnesses such as depression or phobias has also been widely discussed in this context. However, possible molecular relationships have so far been left out. The international research team led by Elisabeth Binder therefore examined the genetic material of almost 2,000 African-Americans in a comprehensive study, "who were traumatized several times as adults or as children," reports the Max Planck Institute. Around a third of the subjects were mentally ill and showed post-traumatic stress disorder as a result of the events they had lived through, while the other study participants were apparently able to process their traumatic experiences better. The scientists compared the genetic sequences of diseased and unaffected trauma victims in order to elucidate “the mechanism of this gene-environmental interaction” and to find out which genetic effect is behind the increased risk of illness.
Special gene variant causes an increased risk of mental illnesses In fact, the "risk of developing post-traumatic stress disorder with increasing severity of the abuse could only be observed in the carriers of a special genetic variant in the FKBP5 gene", according to the Max Planck report Institute of Psychiatry. Only subjects with a corresponding genetic predisposition showed a significantly increased risk of illness after traumatic events in childhood. The variant of the FKBP5 gene is therefore the key to the increasing number of mental illnesses after childhood trauma experiences. The gene “determines how effectively the organism can react to stress hormones and thus regulates the entire stress hormone system,” the Max Planck Institute explained the function of FKBP5.
Genetic changes due to childhood trauma The scientists demonstrated in experiments on nerve cells that "extreme stress and thus high concentrations of stress hormone cause a so-called epigenetic change" of the FKBP5 gene. For example, “a methyl group is split off at this point, which significantly increases the activity of FKBP5,” explains the Max Planck Institute for Psychiatry. The effect is mainly due to trauma in childhood. Study participants who were traumatized only in adulthood showed “no disease-associated demethylation in the FKBP5 gene.” The scientist from the Max Planck Institute for Psychiatry, also involved in the study, explained that trauma in childhood depends on the genetic predisposition leave permanent traces on the DNA. The epigenetic changes in the FKBP5 gene caused “a persistent malfunction of the stress hormone axis in the person concerned”, which in the worst case “can end in a psychiatric illness.” According to the expert, one of the key findings of the current study is “that the stress -induced epigenetic changes can only occur if this special DNA sequence is also available.
New treatment strategies for mental illnesses after childhood trauma The results of the researchers are on the one hand an important contribution to the "understanding of psychiatric illnesses as a result of the interaction of environmental and genetic factors", but on the other hand they can also help "treat people in an individualized manner, in which one person in particular Traumatization in early adolescence has significantly increased the risk of illness, ”reports the Max Planck Institute for Psychiatry. "This identification of molecular mechanisms of genotype-related long-term environmental reactivity will be useful for designing effective treatment strategies for stress-related disorders," the researchers write in the "Nature Neuroscience" article.
However, the current results also raise the question of whether the epigenetic changes caused by child trauma may also be passed on to the children of the victims of the trauma. This must now be examined in further studies. The researchers also hope that the underlying processes can be reversed with drugs in the future, which should also be checked in future studies. (fp)
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