When Dr. Nadine Burke Harris set up the Bayview Child Health Center in 2007, she immediately noticed an association between traumatic experiences and health outcomes in the children she treated.
“Day after day I saw infants who were listless and had strange rashes,” she writes in her new book, The Deepest Well: Healing the Long-Term Effects of Childhood Adversity. “Kids just entering middle school had depression. And in unique cases…kids weren’t even growing.”
Often, she discovered, these children had suffered “heart-wrenching trauma,” such sexual abuse, violence, or parental mental illness and incarceration. These are what researchers call “adverse childhood experiences”—or ACEs, for short. To understand what she was seeing in her clinic, Dr. Harris searched the scientific literature for evidence about the connection between experience and health—and discovered that the impact of an ACE went well beyond childhood, leading to more physical and mental illness in adulthood.
We spoke with Dr. Harris about her new book and what we can do to mitigate the impact of adverse childhood experiences.
Jeremy Adam Smith: What is the origin of the term “adverse childhood experience”?
Nadine Burke Harris: That refers to the 10 categories identified in the landmark 1998 study by Kaiser Permanente and the Centers for Disease Control and Prevention, which include physical, emotional, and sexual abuse; physical and emotional neglect; growing up in a household where a parent was mentally ill, substance-dependent, incarcerated; where there was parental separation or divorce, or domestic violence.
Many of us are familiar with the idea that exposure to adversity in childhood might affect your risk of being depressed or being an alcoholic, and that it might affect your behavior. However, this was the first large epidemiological study to document the association between adverse childhood experiences and heart disease, cancer, chronic lung disease, Alzheimer’s. This is the thing that’s so powerful about the adverse childhood experiences study—it really revealed this connection between childhood adversity and health problems.
JAS: How would an experience affect our health? What’s the mechanism?
NBH: In the two decades since the ACE study was published, we now understand much more about how ACEs affect health.
When the original study was published, many folks assumed that, “Oh, okay, if you have a rough childhood you’re more likely to drink and smoke and do all the things that are going to ruin your health, so this, of course, makes a lot of sense… but it’s not really anything new. We already know that health-damaging behaviors are bad for your health.”
It turns out that that’s not completely right. When they did the logistic regression analysis—removing the effect of health-damaging behavior—it turns out that behavior only accounts for about half of the risk. The good news is that if you don’t do any health-damaging behaviors, that does reduce your risk—but the bad news is that you still have an increased risk.
We know that the fundamental mechanism is this activation of our body’s fight-or-flight response. When we experience something scary or traumatic, it releases stress hormones in our body like adrenaline and cortisol. These things have really important functions in our body. They raise our blood pressure, they raise our heart rate, they raise our blood sugar.
All of these things are really important and necessary if you are facing a mortal threat, like if you are in a forest and there’s a bear. These changes affect how our brains function. They activate the amygdala, which is the brain’s alarm to tell us when something scary is happening. And that turns down the effectiveness of the part of the brain that’s responsible for impulse control and judgment and executive functioning, which is the prefrontal cortex. When we activate our stress response, it also activates our immune system, because if you are in a forest and there’s bear, you want your immune system to be primed to bring inflammation to stabilize the wound This all was designed to protect our lives and protect our health.
What happens when that bear comes home every night? When this system is activated over and over and over again? Well, it goes from being adaptive and life-saving to being maladaptive and health-damaging. Children are especially sensitive to high doses of adversity because their brains and bodies are just developing. So adverse childhood experiences are associated with changes in the structure and function of children’s developing brains, in their developing hormonal systems, and even in the way their DNA is read and transcribed.
JAS: Why would this affect adult health? You start the book by telling the story of Evan, who wakes up one morning and suffers a stroke. How could a bad childhood experience lead directly to Evan’s stroke?
NBH: The chronic inflammation piece is really important. That leads to the wear and tear on the lining on the inside of our arteries, which is part of the reason for why we see increased risk of cardiovascular disease. Adverse childhood experiences studies show that the more of these experiences you have, the greater the health risk. So, folks who have had four or more categories of adverse childhood experiences show two-and-a-half times the risk of stroke.
When our stress response becomes over-activated in childhood, it changes the functioning of the stress response. Without intervention, these changes to levels of stress hormones will be lifelong—and those are the things that lead to increased inflammation and the changes to our cardiovascular system. For example, there are changes to hormones and proteins that our cardiovascular system uses to signal the health and to repair the lining of the inside of our arteries.
JAS: Not everybody who has an ACE will ultimately suffer a stroke. What do we know about people who seem more resistant to the impact of ACEs?
NBH: I hear it all the time: “I know someone who experienced a childhood adversity, and they’re fine.” That’s wonderful. We all know the one dude who smoked two packs of cigarettes a day for years who lived to be a hundred, right? People think of these anecdotal, individual stories and they’re like, “Well, that belies the whole premise.”
That’s why we like science. That’s why it’s really important that they did this study of 17,500 people and that the study has now been repeated globally. We’ve got data from more than 20 countries around the world, and they all show the same thing: The higher your ACE score, the greater your health risk. Now, does that mean that someone could have a high ACE score and not have heart disease or a stroke or something along those lines? Sure. Does that mean that childhood adversity doesn’t put your health at risk? No.
Some people who smoke will get emphysema and other people will get cancer. Two different people will get two different types of cancer. But we know smoking dramatically increases your risk for all of these different health problems. That gives us really important information about how we can prevent those health problems by reducing the prevalence of smoking.
JAS: What can physicians and health organizations do to address the impact of ACEs on both kids and adults? What needs to change from what’s currently being done?
NBH: This is a place where I think there’s a lot of good news, because there’s a tremendous amount of low-hanging fruit. Right now, there isn’t that much that we actually are doing, frankly. This is especially true for physicians. One of the most important things that we can do is routine screening, to do early detection and early intervention. All of the science tells us that early intervention improves outcomes.
There is a randomized controlled trial, published in 2015, of kids in institutionalized care—who had been removed from their home—and kids who were placed in homes with high-quality caregiving. They had MRIs at age two and then MRIs at age eight. And at age eight, those kids who had been randomized into high-quality nurturing caregiving, their brain’s structure was different than the kids who remained in institutionalized care. High-quality nurturing caregiving—safe, stable, nurturing relationships—can actually change the structure of children’s brains, and that is why early detection is really important.
At the Center for Youth Wellness, we have set a goal to get every pediatrician in America to screen for adverse childhood experiences. Despite the fact that this research was published now two decades ago, still, today, only four percent of pediatricians are screening. There’s a lot of room for improvement there, so that we can get to a day when every doctor in America is screening for adverse childhood experiences.
JAS: Let’s say you’re an adult and you have an ACE. What should you do?
NBH: There’s a tremendous amount. On this front, I find this science incredibly hopeful.
One of the most important things an adult can do is just recognize what is going on. So, getting your own ACE score—that is the first step in the right direction. Number two involves figuring out whether you have an overactive stress response—and then understanding what situations activate your stress response.
Next, you have to put into place some of the evidence-based interventions that we know make a difference in toxic stress. This is what I talk about in my book, The Deepest Well. Things like regular exercise, which helps reduce stress hormones, reduce inflammation, and enhance neuroplasticity. Things like having good sleep hygiene, which is really important for our immune system. Things like mindfulness meditation. One randomized controlled trial of meditation-as-intervention found that patients with chronic heart disease had better performance on an exercise treadmill test after the intervention. All of these kinds of interventions go a long way toward counteracting the biology of toxic stress.
“I don't think forgetting about adversity or blaming it is useful. The first step is taking its measure and looking clearly at the impact and risk as neither a tragedy nor a fairy tale but a meaningful reality in between. Once you understand how your body and brain are primed to react in certain situations, you can start to be proactive about how you approach things. You can identify triggers and know how to support yourself and those you love.”
JAS: What are the solutions for us as a society?
NBH: There’s an incredible amount that we can do. There are multiple levels where we can address the impacts of childhood trauma.
There are many schools across the country that are trying to be trauma-sensitive, understanding how to recognize the symptoms of toxic stress, how to differentiate a child having a fear response from one who is just being willful or difficult. There are a lot of kids right now who are being told that they are bad, who are being suspended or expelled, when really the underlying problem is a biological one, with the over-reactivity of their stress response.
If you’re an employer, you can explore workplace policies that support parents’ ability to support their kids, like predictable work hours. Or employers can create a space for workers to practice self-care, to manage their own stress response. For the most part, mental health treatment is not covered in parity with health care. Many folks may have access to health care through their employer, but many, many people still do not have access to mental health care.
Finally, we need to invest in this work. We don’t receive any public funding at the Center for Youth Wellness. We had to invest public funds in addressing public-health threats, like HIV/AIDS or lead poisoning or tobacco. With HIV, it was the Ryan White Act; that required political will. We need folks to come together to demand greater investment in solutions for this public-health problem.