For decades, Martin Teicher, MD, PhD, has investigated the impact of trauma on the developing brain. He is currently an associate professor of psychiatry at Harvard Medical School, where he investigates the effects of Adverse Childhood Experiences (ACEs) on brain development and identifies windows of time when brain regions are most vulnerable to early life stressors and at greatest risk for future mental challenges. Since 1988, he has directed the Developmental Biopsychiatry Research Program at McLean Hospital.

ACEs are potentially traumatic events that occur before age 18 but can undermine mental and physical health across the lifespan. They include physical and emotional abuse or neglect, sexual trauma, and challenges that occur within a home environment, such as substance abuse, mental illness, or separation from a parent or caregiver. In recent decades, ACE assessments have expanded to include the harms of poverty, racism, discrimination, exposure to war and environmental disasters, and the devastating impacts of family separation. An accumulation of ACEs during childhood are implicated in a range of mental health challenges, chronic diseases, and leading causes of death that include cancer, diabetes, and heart disease.

Dr. Teicher wrote the 2018 commentary “Childhood trauma and the enduring consequences of forcibly separating children from parents at the United States border.“ He has also contributed a chapter to the forthcoming book “Developmental Trauma and Resilience, published by the American Academy of Pediatrics, that asserts ACEs can shrink key regions involved in memory and emotional control and rewire sensory responses. MindSite News contributor Simran Sethi, media fellow at the Nova Institute for Health, connected with him to discuss how current immigration policies and other traumatic events are affecting brain development and the potentially devastating impacts they might hold for these children’s futures. 

The interview has been edited for length and clarity.

---

SIMRAN SETHI: Immigration isn’t broadly identified as an ACE or set of ACEs but the arc of immigration holds a lot of potentially adverse experiences like pre-migration stressors—violence or poverty—that may force someone to leave their home plus the stress of migration and the impacts of having to separate from one’s culture and community and resettle in a new place. And now we see the rise of immigration policies that has escalated the detainment of both adults and children, sometimes in really violent ways, to unprecedented levels. This isn’t only breaking up families, but contributing to an environment of justifiable anxiety and fear.

MARTIN TEICHER: Immigration can be a terribly adverse experience. There are two major factors that go into what we consider childhood adversity. It’s having your threat system overly activated—leaving your home, being exposed to violence, seeing things that are frightening, things that you need to learn to avoid or protect yourself from. And it’s also being deprived of things that would normally occur if you weren’t forced to migrate, like going to school or having enough to eat. If you don’t have those things, in some ways, you’re deprived of the usual inputs that are very important for brain development. If you’re forced to migrate, you can lose many of these things.

In your 2018 commentary in BMC Medicine, you write: “Forcibly removing a child from their parents is one of the most profound traumas a child can experience, since it undermines a pivotal foundation they require for self-regulation and resilience.” Why aren’t the long-term harms being considered? 

That’s a tough question. We should be paying a great deal of attention to this, but I don’t think many places around the world care very much about the suffering of immigrants. I don’t think they want to recognize it. And if they do recognize it, I don’t think it’s that impactful for them.

It’s difficult to try to reconcile that. In your forthcoming book chapter, you and your colleagues write, “Child and adolescent brains are highly plastic organs whose development is guided by genetic factors but sculpted by experience,” and go on to describe ACEs as “toxic stressors” that impact brain development. How so?

Your brain is designed, in some ways, to adapt to the situation that you’re in. So when you’re in a setting that’s abnormal, stressful, or terrifying, the brain is going to adapt in ways that are useful for your immediate survival. But those changes may have long-term consequences that are not particularly healthy. 

For instance, if you’re in a situation where you’ve experienced a great deal of conflict or your survival has been at risk and then you’re sent or resettled somewhere where everything is new, the parts of your brain that are involved in detecting and responding to threat get activated. That includes sensory systems that have a direct pathway, even below the level of consciousness, to a portion of the brain called the amygdala.  

The amygdala helps us discern threats and control fear. 

Yes, and it can lead to the production of stress hormones like adrenaline and cortisol. It will also change your thinking and lead you to have fight-or-flight kind of responses. 

Our brains are modified [by stressors]. How they’re modified depends a lot on the age of the child. If you’re an older child, the amygdala becomes hyper-responsive to threat so you can respond appropriately with a fight-or-flight response. But if you are a young kid—5 or 6 years-old—you don’t have the capacity to mount an effective fight-or-flight response. So instead of getting a hyperreactive amygdala response to threat, you get a blunted response and become hypersensitive to neutral stimuli. 

What are the long-term consequences?

You wind up with abnormalities on both ends. The adolescent who’s been exposed to threat will, in a more healthy environment, start to perceive things as threatening that may not be threatening. That puts them at considerable risk for developing depression, anxiety disorders, PTSD, and just over-responding in general. The younger child, conversely, may fail to recognize threats. They will often wind up in situations where they are inadvertently or repeatedly exposing themselves to threatening things because they fail to recognize them as threats. But they’re also very uncertain in situations that seem more neutral or nuanced. 

And these challenges carry over into adulthood? 

They are enduring changes in how the brain is wired that carry over unless treated. We see them in the MRI scanner in the volume of the brain. We can also see them using fMRI in terms of how the brain functions and respond to threats.

And your work shows that even children who appear resilient still carry these neurobiological scars. So, later in life, they can find ways to compensate for that trauma but don’t escape unscathed.

Yes, exactly.

More than one in five children in the United States is foreign-born or has a parent who is foreign-born and could be impacted by expanded immigration policies. When we look at Latino children, that number rises to roughly one out of two children and with Asian kids it’s three out of four. What happens to a child’s brain when they are separated from their parents?

Separating a child from their parent is an incredibly severe trauma, particularly for a younger child. A younger child can tolerate a lot in terms of exposure to stressors if they have parents with them and if those parents are supportive. The parents actually act as buffers; they modify how the brain responds in a younger child and make their amygdala a lot less reactive to threat. Without this, the child is battered by threats. It has a terribly strong impact. 

And when not having our parents there, one of the other things that we’re very sensitive to is betrayal. You feel very betrayed and very deprived by the situation. This is extraordinarily problematic as a traumatic stressor and, as far as we can tell, is also going to have lasting impact.

Let me make sure I understand this idea of betrayal. Say a child is traveling with their parent and the parent gets detained, or a child sees a parent removed from their home or they are forcibly removed from their parent and abandoned on the street. Does the child understand their parent didn’t have a choice in separating? Who do they feel betrayed by?

It’s multifaceted. They may feel betrayed by the parent, like, “Why did you do this? Why did you take us here? Why did you leave home?” Or they may feel betrayed by the system.

And “the system” could mean any number of things: law enforcement, a school, a country …

Very much so. What the child winds up focusing on is that something that they were really counting on—that was, to them, sacrosanct—has just been ripped apart. They’re feeling this grievous wound that can lead to a great deal of anger.

You write that one of the most consistent challenges in people who have experienced ACEs is emotional dysregulation. Why?

What we often see with individuals who experience trauma in their youth is a modified form of PTSD that we would call developmental trauma disorder. It’s PTSD that started in childhood, not from a single event but compounded because of a series of large events. 

A key feature of these individuals is emotional dysregulation, [meaning] it’s very, very hard to control their emotions. That’s because the circuits involved in integrating the prefrontal cortex with the amygdala to allow for top-down regulatory control have not adequately developed. 

The amygdala plays a key role in emotional regulation and hasn’t synched up with the prefrontal cortex that’s responsible for decision making and self-control?

You know when you are going to do something and part of your brain is telling you, “Wait a second, wait a second, don’t do that yet”? When you’re faced with trauma, the development of these executive functions can lag seriously behind. And then you see problems with being unable to inhibit responses that can manifest in high levels of impulsive behavior. People act in ways that can be dangerous because they are not thinking through the consequences. 

They also have a terrible time controlling their emotions. That can make it very hard to have sustained relationships. It can be addressed with treatment, but it’s a real wound that these individuals are likely to suffer. 

And they can also be highly distractible and have a difficult time focusing. And, in terms of IQ, we found that really early exposure [to adverse experiences] can be associated long-term with about a 10-point reduction in IQ. That’s huge.

That is huge. And ACEs don’t just cause harm, they also blunt joy.

One of the brain regions that’s very involved in reward processing is called the nucleus accumbens. When you anticipate a rewarding stimulus—it doesn’t matter if it’s food, sex, money, drugs, video games—it seems to release dopamine into this region. In a number of individuals who have had early adversities, things that normally would feel pleasurable don’t feel pleasurable. That’s a big risk factor for developing major depression. 

What also occurs is that, because so many things aren’t producing pleasure, if they find something that does—say, a very powerful drug—they may be at markedly increased risk for becoming addicted to that drug.

In the context of immigration, something that really stood out to me in your forthcoming book chapter is that “poor impulse control coupled with poor decision-making can lead to engaging in risky behaviors, increasing the likelihood of accidents or legal issues​.” Those potential legal issues could set the stage for eventual detainment or deportation. 

We absolutely set the stage for these things repeating. We do that with immigration. We do that when we engage in hostilities like war. When you set it up in children, you’re affecting their brain development and [problems] that are going to come back 20 years from now. 

So we could say that trauma from the immigration experience itself—like trying to get out of poverty or a hostile situation—could reshape brains and possibly wire people to engage in riskier behaviors that could potentially send them right back to the place they fled?

Yes, exactly. It’s a vicious cycle.

Simran Sethi is a Media Fellow at the Nova Institute for Health, which provided financial support for this series. If you or your loved ones are impacted by current immigration policies, these guides on family preparedness and ICE encounters may help.

This story is reported and produced by MindSite News and co-published by The Xylom, a nonprofit news outlet covering global health and environmental disparities. Subscribe to their newsletter here.