Research & Science
Jun 20
· Written By
Ted Handler, MD

Adverse Childhood Experiences (ACEs) 101

At Oath, our model of care is grounded in fundamental research on childhood stress physiology. Stress response can have cascading effects on how children see the world and their actual longterm health. How? Let’s start with the basics.

What’s Stress Got to Do With It?

At Oath, our model of care is grounded in fundamental research on childhood stress physiology. Oath’s co-founder and Chief Nursing Officer, Dr. Michelle Stephens, has done extensive research in the ways that stress in childhood can shape the way we live our lives, going deep, really deep, into stress physiology. She learned about the ways in which a child’s own nervous system can predispose them to process stress in highly divergent ways. This stress processing response can have cascading effects on how children see the world, how they interpret events, and how they learn from those experiences.

Clearly, there is a lot to unpack here. To understand why anybody chose to learn about stress in the first place, it can be helpful to start with the basics…

ACEs 101

Understanding stress is not a new phenomenon. The term “fight or flight” was first described by Dr. Walter Bradford Cannon, a medical doctor and physiologist, in 1915. Dr. Cannon observed that adrenaline is released into the bloodstreams of animals in response to not only physical threat, such as a physical injury, but also from frightening interactions with members of the same species, such as being yelled at by a good friend.

And yet, while our understanding of the stress response has evolved greatly over the decades, it was a collaboration between Kaiser Permanente and the CDC in 1995 that laid the groundwork for one of the most significant pieces of research to date. Their study examined thousands of adults in Southern California and discovered that the experience of adversity in childhood, after a certain threshold, is actually predictive of alcoholism, drug abuse, depression, and suicide attempts.

Shocking? Perhaps not… it’s not surprising that mentally stressful events lead to mental health illness later in life.

What shocked researchers, and eventually lit the fire under the collective rears of policymakers, was the finding that ACEs can actually predict all kinds of facets of physical health. The study found that the amount of childhood adversity one faces is correlated with the amount of heart disease, cancer, chronic lung disease, skeletal fractures, and liver disease that one has as an adult.

No single clinician has summarized these findings as eloquently as Dr. Nadine Burke Harris in her widely shared TED Talk on this topic. Now, as the Surgeon General of California since 2019, Dr. Burke Harris has made ACEs her top priority, and has launched initiatives to train pediatricians statewide in screening for and recognizing the importance of ACEs in patient health.


The current working hypothesis is that chronic and severe stress reactions, or “toxic stress,” cause persistent exposure to stress hormones such as cortisol. This chronic exposure causes the body to react in maladaptive ways, like aging the arteries to cause high blood pressure, or impacting metabolism to lead to diabetes.

Toxic stress can affect people of all backgrounds. This is not a problem that only afflicts those from a lower socioeconomic class. The important thing to remember, however, is that toxic stress describes a special response to severe, repeated stressful situations. It does not describe the 4 hours of crying you suffered through for sleep training. It does not describe every tear that is shed over a scraped knee. Life has tears and suffering, and those are normal components of raising a child. Oath will not help you to raise a tear-free child. Oath will help you to navigate life with a deep understanding of the role of stress.

Next Steps

Oath believes that a thorough understanding of childhood stress can shape child health for generations. Now that we’ve illustrated the basic importance of stress in child health, you might be asking yourself, “great, so what can do for myself and my child?”

We hope to share more with you about this in the coming weeks. We’ll do a deeper dive into stress physiology in our next post, talk about the ways that toxic stress can manifest outside of just the original ACEs described in this study, and finally focus on some researched treatment and prevention strategies.

If you can’t wait for the punchline, you can read ahead! There are some incredible studies being done in vulnerable populations at the Harvard Center for the Developing Child. You can also check out the work by Dr. Burke Harris as the California Surgeon General. We can’t wait to see you next time for our deeper dive!

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Original ACEs Categories (American Journal of Preventative Medicine)
Risk and Protective Factors (Centers of Disease Control and Prevention)

Ted Handler, MD
Ted Handler, MD

Founding Pediatrician at Oath Care and general pediatrician in the San Francisco Bay Area.