Transgenerational trauma is the subconscious transmission of traumatic experiences to subsequent generations and to society. People in the next generation find themselves showing the symptoms of trauma without having experienced the trauma themselves. Even 20 years ago that idea would’ve been laughed at by most people. But in the ever-intwining worlds of modern psychology and medical technology, humanity is discovering a whole new layer of understanding of mental health within our very genes.
Andrew Curry at Science.org points out, “In animals, exposure to stress, cold, or high-fat diets has been shown to trigger metabolic changes in later generations. And small studies in humans exposed to traumatic conditions—among them the children of Holocaust survivors—suggest subtle biological and health changes in their children.” This change is referred to as an epigenetic change. Epigenetics is the study of how your behaviors and environment can cause changes that affect the way your genes work. Unlike genetic changes, epigenetic changes are reversible and do not change your DNA sequence, but they can change how your body reads a DNA sequence. As Curry pointed out, this can be seen in all animals, in that the actual “tools” remain the same across the species, but how their body utilizes that tool is different.
As mentioned above, understanding epigenetics is key to understanding transgenerational trauma. Almost every cell in our body contains the same DNA sequences, yet it is immediately clear that all our cells do not look and behave alike. Heart cells look and act very differently than those in the lungs, even though both kinds of cells contain the same DNA. The reason for the variety of activities seen in different cells is explained by epigenetics. Epi- is the Greek prefix for “above”. Epigenetic changes provide a way for cells to control and regulate gene activity without changing the genes permanently. Instead, epigenetic control relies on small, reversible, changes to the DNA and proteins that make up chromosomes.
When someone experiences trauma, their brain sets into motion a series of psychological effects that are supposed to protect us from future harm. In this way, the person builds up a toolbox of coping mechanisms that are supposed to spring into action when we sense danger; palms sweating, heart racing, uncontrollable leg movements, and so on. These are the epigenetic changes that are guiding and directing our body and thoughts.
In 2016, Dr. Rachel Yehuda, a neuroscientist at the James J. Peters Veterans Affairs Medical Center in the Bronx, New York, did a research study on Holocaust survivors and their children. Many Holocaust survivors have PTSD and other emotional disorders, and it’s well-known that children of traumatized people are at increased risk for PTSD, but she wanted to see how this represented itself genetically. She and her colleagues showed for the first time in humans that epigenetic changes caused by exposure to trauma can be passed on to children born after the event—in this case Holocaust survivors and their adult children. Epigenetic processes alter the expression of a gene without producing changes in the DNA sequence and can be transmitted to the next generation (Click here to read the full study).
Her team tested blood samples of 32 Holocaust survivors and 22 of their adult children for methylation of intron 7, an area in the FKBP5 gene. For a control group, they analyzed Jewish parents who lived outside of Europe during World War II—most were U.S.- or Canadian-born—and their offspring. Interestingly, Holocaust survivors and their children showed epigenetic changes at the same site of FKBP5 intron 7 but in the opposite direction. Survivors had a 10 percent higher methylation than the control parents, while the Holocaust children had a 7.7 percent lower methylation than the control children.
“The observation that the changes in parent and child are in opposing directions suggests that children of traumatized parents are not simply born with a PTSD-like biology,” Dr. John Krystal, a research psychiatrist at the VA Connecticut Healthcare System and editor of Biological Psychiatry, said in a news release. “[The children] may inherit traits that promote resilience as well as vulnerability.”
The implications of this are astounding. Childhood trauma has been associated with posttraumatic stress disorder (PTSD), anxiety, depression, bipolar disorder, diabetes, and cardiovascular disease, amongst other issues. And it makes sense within the individual experiencing the trauma to develop these problems, but when one considers the idea that a descendent of a Holocaust survivor, or the grandchild of a slave, could still be prone to these reactions, it becomes even more serious of an issue.
It's important to note, however, that the results of these studies on transgenerational trauma don’t point to the idea that someone will automatically be born with mental health issues. It points to the idea that certain alterations within the epigenetics of a person can make them more prone to psychological problems, as a result of the trauma. According to a neural diathesis-stress model, genetic predisposition and environmental factors contribute synergistically to the development of mental disorders.
And why Is all of this important to know? Because when we’re armed with this knowledge that previous generations may have experienced trauma that is affecting ourselves, we can be proactive in our mental health treatment. We can seek out therapy, which can reveal unhealthy coping mechanisms and give us healthy ones to replace them. We can seek out others who can relate to our upbringings, which may reveal to us that we have unhealthy habits, behaviors, and thoughts, and maybe they can share their own methods for combating them. It’s great to know why we may think or act in certain ways, but that knowledge means nothing if we don’t use it to grow.