A woman's risk of anxiety and other psychiatric disorders may depend on how stressed out her father was when he was young, scientists claim.
Findings from a new study suggests that the stress a man experiences when he is young can contribute to epigenetic changes in his sperm cells that can result in mental problems in female offspring.
What's even more frightening is that these genetic mutations caused by stress experienced during a man's youth can also be passed down through multiple generations, from daughters to granddaughters and so forth, according to the study published in Biological Psychiatry.
Scientists from the Tufts University School of Medicine tested their theory by subjecting young male mice to a range of environmental stresses like frequently changing the arrangement of their cages.
While the stresses led the mice, particularly female mice, to become significantly more anxious and socially dysfunctional than mice that had not been exposed to stress, female offspring, but not male offspring, of these previous-stressed mice exhibited elevated anxiety and poor social interactions.
Researchers emphasized that while the stressed male mice did not express any changes in their behavior, they passed on these behaviors to their female offspring, even after being mated to non-stressed females.
Furthermore, the team found that male offspring of previously stressed mice passed on these behaviors to yet another generation of female offspring.
"The long-term effects of stress can be pernicious. We first found that adolescent mice exposed to chronic social instability, where the cage composition of mice is constantly changing, exhibited anxious behavior and poor social interactions through adulthood. These changes were especially prominent in female mice," study author Lorena Saavedra-Rodríguez said in a statement.
Researchers are now looking for any biochemical changes in the sperm of stressed fathers that could account for this type of inheritance.
"Hopefully, this work will stimulate efforts to determine whether similar phenomena occur in humans," Co-author Larry Feig, professor of biochemistry at Tufts, said in a statement.