Researchers cast light on science behind trauma of domestic violence

There has been a growing awareness in recent years that traumatic events can rewire minds and bodies in all sorts of ways that corrode health and shorten life spans.

While much of the journalistic coverage of these themes over the past decade has focused on early childhood, two speakers at the Center for Health Journalism’s 2021 Domestic Violence Symposium recently walked reporters through some of the science of the trauma caused by domestic violence, with the goal of spurring deeper coverage of how such abuse can leave lasting devastation.

Karestan C. Koenen, a professor of epidemiology at the Harvard T.H. Chan School of Public Health, researches the ways in which trauma harms women’s mental and physical health over the course of their lives.

She says that interpersonal violence — a broad category that includes domestic violence, sexual assault, and child abuse — disproportionately harms younger people. “Most people who are going to be exposed to those events have experienced them by the time they’re 18,” she said.

One of the more common responses to such trauma is post-traumatic stress disorder, Koenen explained, a situation in which the body’s system of self-preservation gets stuck on high alert, with the state of fear persisting long after the immediate danger passes. Trauma recovery tends to be slower for those who suffer from it. And interpersonal violence is a major driver of this form of trauma.

“The majority of PTSD burden in the U.S. is due to physical and sexual violence,” Koenen said.

The scale of the problem becomes even starker when you consider how prevalent domestic and sexual violence is for women in the United States. In one large well-known cohort study of women who have been followed since 1989, more than 43% reported experiencing interpersonal or sexual violence in their lifetimes, according to data Koenen presented. The average age at the time was 15.

The cumulative effects of such violence on women’s health falls into two broad categories: changes in behaviors that in turn impact health, and more direct changes to the body’s stress-response system, which can trigger inflammation and a host of chronic diseases.  Koenen said that women who develop PTSD tend to reduce their physical activity, increase TV viewing and change their diets. “We find that women who develop PTSD develop higher body mass index and that they have increased weight trajectories over time,” she said.

Women with PTSD are more likely to suffer from chronic diseases such as diabetes, heart disease and ovarian cancer. “Sexual violence in particular is associated with increased risk of hypertension,” Koenen said.

In Koenen’s own research, PTSD is associated with a higher risk of cognitive decline and early mortality, and she is now looking at whether PTSD can lead to accelerated aging. (Women who suffer from it also tend to have shorter chromosomal telomeres, one biological measure of aging.)

Unpublished data from Koenen’s work also suggest that women with PTSD are more likely to have reported a head injury. “Head injury may be an under-recognized contributor to the adverse effects of trauma in these women,” she said.

That’s certainly not news to Eve Valera, an associate professor of psychiatry at Harvard Medical School, who has spent years trying to raise awareness of how common and devastating traumatic brain injuries are among victims of partner violence.

Traumatic brain injuries “are far more common in intimate partner violence than any one has ever thought of or wanted to believe,” Valera said, urging journalists to cover the issue. “Most people are not talking about it. Most people do not think about it. There are very few stories that ever address this in the lay literature.”

When she first started researching the issue early in her career, she struggled to find a single article in the medical literature about brain injuries stemming from partner violence. While awareness of brain injuries among football players and the armed forces has grown in recent years, women have been overlooked.

In a 2003 study, Valera and a colleague conducted extensive interviews of 99 victims of domestic violence. They found nearly three-quarters had suffered at least one brain injury, and half had multiple brain injuries from their partners.

“One of the really unfortunate facts about intimate partner violence is that 80% to 90% of the injuries are to the head or to the neck,” she told journalists. “When I have done interviews with the women that I have had in my studies, I have heard women tell me about how they were stomped on the head with work boots, beat repeatedly on the head with fists, smashed in the head with hammers, and batted in the head with a baseball hat.”

Such brain injuries are associated with poorer outcomes on memory and learning tests, depression and anxiety, and other mental health problems. Valera said there is also emerging evidence that just injuries are tied to reduced brain connectivity. “The more recent and greater number of TBIs a woman had, the less positively these two brain regions communicated with one another,” she said.

The pandemic lockdowns have only added to the urgency of the crisis. “Intimate partner violence-related traumatic brain injuries have probably escalated during COVID, but we don't even talk about it.”

But the unsettling fact remains that there aren’t reliable numbers on how many people have sustained potentially life-altering brain injuries from partner violence.

“The bottom line is we need to do more research,” Valera said. “We need to have really good epidemiological data, which we just don’t have.”

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