Adverse Childhood Experiences, often referred to as ACEs, are stressful or traumatic events that occur during childhood and adolescence, from birth through age 18. These experiences can include exposure to abuse, neglect, and various forms of family or household dysfunction. At their core, ACEs disrupt a child’s sense of safety, stability, and belonging. They interfere with healthy bonding and can quietly shape how a child grows, learns, and moves through the world.
While ACEs are experiences that happen early in life, their impact does not stay there.
Research consistently shows that exposure to ACEs is strongly associated with increased risk for both mental and physical health conditions later in life. These include anxiety, depression, substance use disorders, cardiovascular disease, chronic lung and kidney disease, and even premature death. What makes ACEs especially concerning is not only what happens to children, but how those experiences become embedded in the body over time.
How Adversity Gets “Under the Skin”
There are two primary pathways researchers use to explain how ACEs influence long-term health. One pathway is indirect. Children exposed to chronic stress are more likely, over time, to adopt coping behaviors that increase health risks, such as poor nutrition, physical inactivity, smoking, or substance use.
The second pathway is more direct and biological. Chronic exposure to stress during sensitive developmental periods can disrupt the body’s stress-response systems. This includes changes in brain structure and function, epigenetic modifications that affect how genes are expressed, and prolonged activation of neurobiological systems such as the hypothalamic-pituitary-adrenal (HPA) axis and the sympathetic nervous system. When these systems are repeatedly activated, the body remains in a heightened state of alert. Over time, this constant “wear and tear” can alter immune function, hormone regulation, and organ systems in ways that increase vulnerability to disease.
Emerging evidence suggests that this biological embedding can occur very early in life, sometimes well before adulthood, and independently of later behaviors. Stressful experiences from conception through adolescence can set off cascading physiological responses that permanently shape how the body responds to stress.
The Visible and Invisible Scars of ACEs
The impact of ACEs often shows up in both visible and invisible ways. Children may experience internalizing challenges such as anxiety, depression, and withdrawal, or externalizing behaviors such as aggression and difficulty regulating emotions. Learning challenges and attention difficulties are also common. These are not character flaws. They are adaptive responses to environments where safety was uncertain.
Researchers, including Soares and colleagues, have sought to understand which adverse experiences are most closely linked to measurable biological changes and which physiological systems are most affected. Their work highlights that ACEs do not simply affect emotional wellbeing. They disrupt the normal functioning of multiple bodily systems, reinforcing the connection between early adversity and later disease.
The Original ACE Framework
The foundational research on ACEs comes from the CDC-Kaiser ACE Study, which identified ten core categories of adversity:
Abuse
Emotional abuse includes being regularly insulted, humiliated, or threatened by a parent or adult in the home.
Physical abuse involves being pushed, grabbed, slapped, hit, or physically harmed.
Sexual abuse includes unwanted sexual touching, coercion, or assault by an older person or family member.
Neglect
Emotional neglect occurs when a child feels unloved, unsupported, or emotionally unsafe.
Physical neglect involves unmet basic needs such as food, clean clothing, medical care, or appropriate supervision.
Household Challenges
These include witnessing violence toward a caregiver, living with a household member who struggles with substance use or mental illness, experiencing parental separation or divorce, or having a household member who is incarcerated.
This framework was groundbreaking, but it was not complete.
What the Data Left Out
The original ACE study did not fully capture the lived realities of children growing up under the weight of racism, colonization, community violence, poverty, and structural inequality. These experiences are real, measurable, and deeply impactful, particularly in Black, Brown, Indigenous, and historically marginalized communities. Their exclusion from early ACE frameworks has limited how we understand adversity and healing at a population level.
What Comes Next
In Part Two of this series, we will explore Expanded ACEs, also known as a culturally grounded view of childhood adversity, as defined by Dr. Mariel Buque. This framework acknowledges the broader social and historical forces that shape childhood experiences and helps us move closer to a more honest, inclusive understanding of trauma, resilience, and healing.
Because healing does not begin with what is measured.
It begins with what is finally named.
References
Centers for Disease Control and Prevention. (2023). About adverse childhood experiences (ACEs). https://www.cdc.gov/aces/about/index.html
Centers for Disease Control and Prevention. (2023). Preventing adverse childhood experiences (ACEs). https://www.cdc.gov/aces/prevention/index.html
Felitti, V. J., Anda, R. F., Nordenberg, D., Williamson, D. F., Spitz, A. M., Edwards, V., Koss, M. P., & Marks, J. S. (1998). Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults: The Adverse Childhood Experiences (ACE) Study. American Journal of Preventive Medicine, 14(4), 245–258. https://doi.org/10.1016/S0749-3797(98)00017-8
Shonkoff, J. P., Boyce, W. T., & McEwen, B. S. (2009). Neuroscience, molecular biology, and the childhood roots of health disparities: Building a new framework for health promotion and disease prevention. JAMA, 301(21), 2252–2259. https://doi.org/10.1001/jama.2009.754
Soares, A. L. G., Hammerton, G., Howe, L. D., Rich-Edwards, J., Halligan, S., Fraser, A., & Howe, L. D. (2016). Adverse childhood experiences: A systematic review of their impact on later health outcomes. American Journal of Preventive Medicine, 50(6), 745–756. https://doi.org/10.1016/j.amepre.2015.12.016
Buqué, M. (2022). Break the cycle: A guide to healing intergenerational trauma. Penguin Life.