A study conducted by Santavirta et al., (Uppsala University) and published in the journal of JAMA Psychiatry.sought to answer the question as to whether the adverse effects of childhood trauma could alter a person’s genes and, if so, whether these genetic changes could be passed on to the next generation in a damaging way.
The study involved examing the medical records of 3000 children of Finnish people who, as children, were evacuated during World War 2 to Sweden. Many were under the age of 5 years and were required to learn Swedish; all were placed with Swedish foster families. The medical records of these 3000 children of former evacuees were compared with the medical records of children of parents who were NOT evacuated as children.
FINDINGS FROM THE STUDY:
Children of parents who were evacuated during WW2 were found to have quadruple the risk of developing serious mental health conditions compared to children of the non-evacuated.
Children of mothers who were, as children, evacuated during WW2 were found to be at an elevated risk of being hospitalized for a mental health condition. However, no such elevated risk was found to be associated with children of fathers.
INTERPRETATION OF THESE FINDINGS:
The researchers who conducted the study suggested that it was probable that these findings were due to the childhood trauma experienced by those who had been evacuated as young individuals altering their gene expression (technically known as epigenetic alterations) which were subsequently inherited by their offspring, making them more susceptible to developing problems with their mental health.
However, the researchers also conceded that children of parents who were evacuated during WW2 may also have been at greater risk of developing poor mental health because the childhood trauma experienced by their parents impaired there ability to parent effectively.
Furthermore, more research will be needed in the future to help cast light upon the finding that children of formerly evacuated mothers were at greater risk of being hospitalized with a mental health condition whilst this was not found to be the case in relation to children of formerly evacuated fathers.
EVIDENCE FROM ANIMAL STUDY:
In an animal study (Franklin et al., 2010) investigating if high levels of stress in early life experienced by animals can adversely affect future generations, mice were subjected to chronic and unpredictable stress (by being separated from their mothers) for the first fortnight of their lives). As adults, these ‘traumatized’ mice, as would be expected, were found to have developed depressive symptoms.
However, it was also found that the offspring of the male, ‘traumatized’ mice also developed depressive symptoms, despite the fact that they were raised in a normal manner. The conclusion drawn by the researchers was that the third generation mice must, therefore, have inherited their depressive symptoms via the process of epigenetic transmission.
CONCLUSION:
Such research suggests that the effects of trauma can be passed on to future generations via epigenetic transmission both in animals and humans; however, research in this sphere of study is in the early stages, and more will be needed in the future.
A DEFINITION OF EPIGENETICS: the study of how alterations in how genes express themselves (e.g., as a result of early life trauma) can be inherited by the next generation. However, it should be noted that the underlying DNA structure of these affected genes is not changed (i.e., there is a change in phenotype, not genotype).
David Hosier BSc Hons; MSc; PGDE(FAHE).
