The past is never dead. It’s not even past.
— William Faulkner, Requiem for a Nun
A well-documented feature of trauma, one familiar to many, is our inability to articulate what happens to us. We not only lose our words, but something happens with our memory as well. During a traumatic incident, our thought processes become scattered and disorganized in such a way that we no longer recognize the memories as belonging to the original event. Instead, fragments of memory, dispersed as images, body sensations, and words, are stored in our unconscious and can become activated later by anything even remotely reminiscent of the original experience. Once they are triggered, it is as if an invisible rewind button has been pressed, causing us to reenact aspects of the original trauma in our dayto-day lives. Unconsciously, we could find ourselves reacting to certain people, events, or situations in old, familiar ways that echo the past.
I listened closely as Jesse spoke. What stood out for me was one unusual detail—he’d been extremely cold, “freezing” he said, just prior to the first episode. I began to explore this with Jesse, and asked him if anyone on either side of the family suffered a trauma that involved being “cold,” or being “asleep,” or being “nineteen.”
Jesse revealed that his mother had only recently told him about the tragic death of his father’s older brother—an uncle he never knew he had. Uncle Colin was only nineteen when he froze to death checking power lines in a storm just north of Yellowknife in the Northwest Territories of Canada. Tracks in the snow revealed that he had been struggling to hang on. Eventually, he was found facedown in a blizzard, having lost consciousness from hypothermia. His death was such a tragic loss that the family never spoke his name again. Now, three decades later, Jesse was unconsciously reliving aspects of Colin’s death—specifically, the terror of letting go into unconsciousness. For Colin, letting go meant death. For Jesse, falling asleep must have felt the same.
In an attempt to explain stories such as Jesse’s, scientists are now able to identify biological markers— evidence that traumas can and do pass down from one generation to the next. Rachel Yehuda, professor of psychiatry and neuroscience at Mount Sinai School of Medicine in New York, is one of the world’s leading experts in posttraumatic stress, a true pioneer in this field. In numerous studies, Yehuda has examined the neurobiology of PTSD in Holocaust survivors and their children. Her research on cortisol in particular (the stress hormone that helps our body return to normal after we experience a trauma) and its effects on brain function has revolutionized the understanding and treatment of PTSD worldwide. (People with PTSD relive feelings and sensations associated with a trauma despite the fact that the trauma occurred in the past. Symptoms include depression, anxiety, numbness, insomnia, nightmares, frightening thoughts, and being easily startled or “on edge.”)
Yehuda and her team found that children of Holocaust survivors who had PTSD were born with low cortisol levels similar to their parents, predisposing them to relive the PTSD symptoms of the previous generation. Her discovery of low cortisol levels in people who experience an acute traumatic event has been controversial, going against the long-held notion that stress is associated with high cortisol levels. Specifically, in cases of chronic PTSD, cortisol production can become suppressed, contributing to the low levels measured in both survivors and their children.
Yehuda discovered similar low cortisol levels in war veterans, as well as in pregnant mothers who developed PTSD after being exposed to the World Trade Center attacks, and in their children. Not only did she find that the survivors in her study produced less cortisol, a characteristic they can pass on to their children, she notes that several stress-related psychiatric disorders, including PTSD, chronic pain syndrome, and chronic fatigue syndrome, are associated with low blood levels of cortisol. Interestingly, 50 to 70 percent of PTSD patients also meet the diagnostic criteria for major depression or another mood or anxiety disorder.