A mix of genes and toxic childhood stress often lead to depression, anxiety and other mood disorders, according to a University of Texas at Austin researcher. With that knowledge, doctors may someday be able to predict who is at risk for mood disorders and offer a plan for prevention.
Dr. Charles Nemeroff chairs the Department of Psychiatry at the University of Texas at Austin. He told those who attended the UT Health San Antonio Brain Health Symposium on Mood Disorders that all people are born with a genetic blueprint that includes gene variants that put them at risk for certain health problems if the environment is right.
For example, if someone has a gene variant that puts them at risk for cancer, they may remain cancer-free unless — or until — they are exposed to something in the environment that activates that risk, like cigarette smoke.
Nemeroff said toxic stress and maltreatment during childhood — like cigarette smoke — can also influence what your genes do.
"It turns out that there are certain gene variants that interact with childhood maltreatment to regulate your relative vulnerability for depression, post-traumatic stress disorder and other disorders," Nemeroff said.
Furthermore, he said, his research has found people with gene variants that might predispose them to developing a mood disorder don’t develop if they never experience child maltreatment.
"In our studies there was no effect of the gene variants of having the vulnerability gene if you were never exposed to childhood maltreatment, but if you were, there it is," Nemeroff said.
Nemeroff said all of a person's gene variants add up to a polygenic risk score. A polygenic risk score looks at all gene variants that may put a patient at risk for a certain disease or disorder, and calculates the risk that the patient will develop it.
"We will in the future be able to look at individuals and say your polygenic risk factor score suggests that you're vulnerable to bipolar disorder or depression or diabetes or asthma," Nemeroff said.
Armed with that knowledge, a patient — or their parents — could avoid things that would trigger their genetic vulnerabilities, decreasing the chance that they’ll develop the associated disease or disorder.
Nemeroff said, however, the environment that can trigger mood disorders — child maltreatment — shouldn’t happen to any child, ever. He said the focus now should be less on risky gene variants and more on ending what he calls an epidemic of child abuse in the United States. He suggested organizations like the National Institutes of Health focus on preventing child maltreatment.
"You know, we put — appropriately — tons of money into AIDS research, and look what happened? We developed treatments. We reduced all the misery that resulted in,” Nemeroff said. “Why can't we do that with child abuse?”
Nemeroff added that genes don’t have to be destiny, and child abuse is 100% preventable.