Toxic Stress

By Nadine Burke Harris
Too Small to Fail Advisory Council member Nadine Burke Harris, MD, MPH, FAAP, is founder and CEO of Center for Youth Wellness. She also serves as advisor on Governor Jerry Brown's "Let's Get Healthy California" Task Force and as a committee member of the American Academy of Pediatrics' Medical Home for Children Exposed to Violence Committee.

April 16, 2014

Chances are, you know someone whose child has been diagnosed with Attention Deficit Hyperactivity Disorder. Perhaps your own child has received this diagnosis. In many cases, it’s a legitimate issue, and can require medication, therapy or both.

But in my experience, ADHD is one of the diagnoses that can be given – precipitously – to children whose behavior issues are not really about inattention. Their behavior is just one outward sign of a much larger public health problem that we are still working to fully understand: toxic stress.

I observe its effects every day in the clinic where I practice as a pediatrician in Bayview, one of San Francisco’s poorest neighborhoods.

Babies have emotions, too

When we think of the emotional life of a baby, we often reduce the child’s feelings to the way he behaves around a few daily activities. We hear an infant cry when he needs to eat, or sleep, or when he feels uncomfortable. And most caretakers tune in and attend to those needs.

But an infant’s well-being is not just about food, rest and diapers. There’s a lot more going on inside a baby’s brain and heart that we can nurture and foster.

Babies and toddlers have a complex emotional life, just like adults.

They are constantly observing their caregivers and the world around them to piece together their relationship to their environment.

During the critical developmental years, between birth and age four, some children experience high anxiety or fear because their home environment is unsafe. They’re subject or witness to physical or emotional abuse, or even extreme poverty. And this trauma can have a tremendous impact on their physical brain development, as well as their emotional development, at a stage when a child is forming the most important attachments in life.

“Toxic stress” is not typical stress

Every child experiences some stress growing up – and even some upsetting events. That’s normal. And learning to cope in those situations is actually necessary for the brain and the body, because it helps a child navigate a complex world and bounce back when trouble arises. Even in a crisis, when a caretaker is there to help a child cope in a healthy way, it strengthens the child’s ability to trust. Those kinds of experiences qualify as “positive” or “tolerable” stress.

But when a child endures something extremely stressful, especially if it is repeated or takes place over a long period of time– without adequate emotional support, this leads to prolonged activation of the body’s stress response system. That’s called “toxic” stress. And it can affect the way the brain and body grow and develop.

Some examples of those painful experiences, also called “ACEs,” or “adverse childhood experiences,” include physical and emotional abuse, neglect, having a caregiver who is mentally ill or substance-dependent, or being exposed to violence without enough support from a loving adult.

Pain in childhood can lead to illness in adulthood

Prolonged or extreme adversity in childhood can cause damage emotionally, socially and physically.

Caregivers, teachers and health providers often see the impact of toxic stress most clearly in a young child’s behavior. We’ll observe a child who is defiant, loses control a lot, has trouble paying attention or has developmental delays that we can’t attribute to an underlying physical problem.

And toxic stress affects more than outward behavior. Below the surface, it manifests itself in actual physical changes in the brain and the body.

Like several other researchers, I have studied the link between ACEs and health. The groundbreaking study in this area, published in 1998, found that a person with four or more adverse experiences in childhood had 2.6 times the risk of the lung disease COPD (chronic obstructive pulmonary disease) of someone with no adverse experiences.

ACEs can also heighten the chance of obesity, stroke, cancer, asthma and diabetes, as well as multiply the risk of hepatitis, depression and heart disease.

Stress sets off a chemical reaction

ACEs directly affect a child’s body by activating the same kind of “fight-or-flight” response you’d experience if, say, you came into contact with a bear. The heart pounds, and the body releases hormones that cause chemical reactions.

Chronic stress can mean frequent triggering of this chemical response, and that can be harmful to a child’s development long-term. It can lead to chronic inflammation, and affect the part of the brain that is implicated in addictive behavior.

The more adverse experiences a child has, the more likely s/he is to develop a host of risky behaviors and negative outcomes later in life, such as alcohol and drug abuse, teen pregnancy or even suicidal tendencies that can cause serious harm or greatly diminish the prospects of a healthy and successful adulthood.

A caregiver is a child’s best buffer

Even in an atmosphere where stress is frequent and not controllable, a young child’s parent or caregiver is the number one shield against the effects of toxic stress. Babies and toddlers are sponges. They absorb many emotions – and tensions – in the atmosphere and people around them. But when there’s a caregiver who can help the child manage these difficult feelings and develop resilience, it can prevent the development of toxic stress.

The quality of a caregiver’s interaction with a child is a key building block for healthy emotional, social and even physical development. Research has shown that something as subtle as a parent’s facial expression and tone of voice will affect even a young infant.

Some of the best ways to support a child’s health and development involve simple things like smiling and laughing, taking time to play with a child one-on-one, and just slowing down to spend time together.

A caregiver’s mental health affects a child

Probably the most important way to create stability and safety for children is for caregivers to tune in to their own emotional well-being, and take steps to improve both physical and mental health.

Parents want to do what’s best for their children. And a lot of parents are very hard on themselves. Really, they’re doing the best they can under very trying circumstances. But many caregivers suffer from the effects of stress themselves, consciously or unconsciously. In fact, most parents cite the task of raising a family itself as a significant source of stress.

Depression in parents affects children physically and psychologically. It can lead to problems with behavior and school performance in the early years, and still have an impact well into adulthood. Even when children don’t acknowledge a caretaker’s mental illness or emotional instability, they pick up on it, and are deeply affected. In my practice, I work closely with caretakers to make sure they are connected with whatever resources they need to be healthy. It’s so critical in an environment where that caretaker is literally a child’s lifeline.

Therapy can also help limit the impact of toxic stress

Even beyond being a healthy and stable caregiver, it’s important to consult a doctor about how best to treat a child who has experienced significant adversity. Some children need therapy to manage the after-effects of trauma.

In my practice, many children show dramatic improvements when they are given, or taught how to use, various coping mechanisms, from mindfulness and meditation to biofeedback.

Often, the best way to help a child handle chronic adversity is for both the caregiver(s) and child to get counseling. Consulting a therapist can help a caregiver address his or her own possible childhood trauma, and can empower the caregiver to act as a strong buffer for a child. By addressing a caregiver’s own barriers to attachment, we can promote attachment with a child, and give the child the best possible chance for healthy development.