Research conducted at the University of Wisconsin-Madison found that girls who grow up in stressful environments are more likely to experience physical and emotional problems, including anxiety, depression and mood disorders.
The research was conducted by Leslie Seltzer, a researcher at UW-Madison’s Waisman Center; Ligia Papale, neuroepigenetics researcher; Reid Alisch, neurosurgery professor at UW-Madison; Seth Pollak, psychology professor at UW-Madison and Andy Madrid, Ph.D student at UW-Madison.
“We found that early childhood environments are related to physical and emotional conditions of kids,” Seltzer said.
The researchers compared the whole genomes of children with very high-stress early lives to those of kids whose childhoods were relatively calm. They found differences in how their genes function. These differences may point out better ways to diagnosis and treat stress-related disorders.
“Our hope is that we can use molecular approaches and maybe some of the genes defined here to sort of refine our diagnosis at the individual level,” Alisch said. “That could make diagnosis and treatment more precise for each individual.”
They were looking for a molecular modification called methylation. In methylation, environmental factors spur changes in a particular molecule.
The researchers found 122 genes where methylation of the high-stressed kids’ DNA differed from their low-stress counterparts. The team also looked at how genes were expressed. In all, more than 1,400 genes showed a difference in expression connected to the amount of stress the girls had experienced.
According to Seltzer, the group of high-stressed children’s genes was not producing proteins.
“That part of their gene was turned off,” she said.
There were also differences in serotonin levels between the two groups.
The experiment involved breaking the girls into two groups. One group had girls who lived tranquil lives and the other had girls who lived very stressful lives. The researchers took saliva from 22 girls from ages 9 to 12, and analyzed samples to see which genes worked at managing biological processes.
“We deliberately choose children who grew up in the highest level of stress and the highest level of tranquility, and broke them up into two groups,” Seltzer said.
This research might allow researchers to see how childhood stress can cause mental and physical disorders, but more research still needs to be done.
“Our analysis identified differences in genes that help regulate mood and attachment, such as those for oxytocin and serotonin receptors. Those are exciting because we may be seeing the mechanism via which childhood stress can cause social or behavioral problems,” Seltzer said. “But we’ve also flagged a lot of genes whose jobs still aren’t clear. Now we know that they may deserve more study for playing a part in stress-related psychiatric disorders, or in the stress response itself.”
Something else future research needs to do is test boys along with girls, according to Seltzer.