When kids witness a death, suicide or violence close to home, the potential psychological damage is obvious. But could there be genetic or physical consequences as well?
A new Tulane University study suggests that there are; it adds to a growing body of evidence showing that traumatic events can leave a lasting impact on children, both psychologically and physically.
According to the study, published in the journal Pediatrics, kids who experienced one or more traumatic events in their home life – incarceration of a parent, suicide of someone in the family or violence in the home — also carry the genetic markers that indicate future health problems such as obesity, heart disease and diabetes.
The study's lead author, Tulane professor Stacy Drury, took a closer look at a genetic marker that's been linked with negative health outcomes later in life: the length of a person's telomeres.
Telomeres are DNA elements that cap the ends of chromosomes, and they become shorter when cells divide and age. But shorter telomere lengths have also been associated with stress-related diseases such as obesity, cardiovascular disease and diabetes.
The study surveyed and tested the DNA of 80 kids between the ages of 5 and 15 in New Orleans; those who had experienced more family-related violence at home were found to have shorter telomeres.
"The more adverse childhood events you have when you're little, the greater the risk of pretty much any health condition when you get older," Drury said in an interview. "That's a biological type of scar that happens when you're a kid.”
Researchers aren't sure exactly why there has been an association with telomere length and disease. It could be that they are a genetic harbinger of future health problems.
But Drury said that a crucial finding was that the relationship between stresses at home due to violence and disruption showed up even when they controlled for socioeconomic status.
"The impact of these negative life events ... it's different than poverty; it's not just about socioeconomic status," Drury said. "Traumatic events, if people are exposed to them early in life, can have a biological impact no matter where you are."
There were, however, differences between genders.
There were indications that girls were more affected by family instability than boys. And the higher the child's mother's level of education, the more boys were protected from the negative consequences of family instability, which Drury said might indicate that for some children, the consequences of negative events can be buffered by parent-child interactions.
Of course, more research is needed to determine why these differences appear.
According to Drury, the findings of this study and others that show a relationship between telomere length and "community disorder" (as well as telomere length and early injury to the child, such as prenatal exposure to tobacco) suggests that children may carry the consequences of childhood trauma well into their adulthood.
"We see that the more events that you're exposed to of those three [community, family and direct violence] the greater the impact," she said.