Childhood trauma alters genes and can be passed onto future generations, new research has found. A study examining the offspring of children displaced during the Second World War revealed they were up to four times more likely to suffer from serious mental health conditions compared to those whose parents stayed at home.
In the largest investigation ever of its kind, researchers examined the health records of 3,000 children of Finnish people evacuated to Sweden during the 1941-45 conflict with Soviet Russia.
The evacuees, many of whom were at a pre-school age, were placed with foster families in Sweden and were forced to learn Swedish, later returning to Sweden.
The study found that the children of these girls had an increased risk of being hospitalised for conditions such as depression and bipolar disorder, however this was not replicated among children of boys displaced during the war.
Its authors say the effect may be partially explained by poor parenting by the evacuees, but they believe it is more probably due to epigenetic alterations – changes to the way genes are expressed – which are then inherited.
A previous smaller study found that Holocaust survivors had higher levels of methyl groups associated with a gene that influences the production of the stress hormone cortisol.
However, the new research, published in the journal JAMA Psychiatry, shows a widescale link between childhood trauma in women and the mental health of the next generation.
“The Finnish evacuation was intended to protect children from the many harms associated with the country’s wars with the Soviet Union,” said study co-author Dr Torsten Santavirta, from Uppsala University.
“Our observation of long-term psychiatric risk that reached into the next generation is concerning and underscores the need to weigh benefits as well as potential risks when designing policies for child protection.”
