Adverse Childhood Experiences (ACEs) and Toxic Stress

The first California Surgeon General, Dr. Nadine Burke Harris, set a bold goal to reduce ACEs and toxic stress by half in one generation. Under the leadership of Gov. Newsom, and in partnership with California Health and Human Services Secretary Dr. Mark Ghaly and statewide health and community leaders, the Office of the California Surgeon General is advancing systemic reforms that recognize, and respond to, the effects of ACEs on lifelong health.

About ACEs and Toxic Stress

An overwhelming scientific consensus demonstrates that cumulative adversity, particularly during critical and sensitive developmental periods, is a root cause to some of the most harmful, persistent and expensive health challenges facing our nation.

The term Adverse Childhood Experiences or “ACEs” comes from the landmark study of the same name published by the CDC and Kaiser Permanente over two decades ago and specifically refers to the ten categories of stressful or traumatic events assessed in the study. These include physical, emotional or sexual abuse, physical or emotional neglect or “household dysfunction” including parental incarceration, mental illness, substance dependence, parental separation or divorce, or intimate partner violence.


Childhood trauma isn’t something you just get over as you grow up. Pediatrician Nadine Burke Harris explains that the repeated stress of abuse, neglect and parents struggling with mental health or substance abuse issues has real, tangible effects on the development of the brain. This unfolds across a lifetime, to the point where those who’ve experienced high levels of trauma are at triple the risk for heart disease and lung cancer. An impassioned plea for pediatric medicine to confront the prevention and treatment of trauma, head-on.


A robust body of literature demonstrates that ACEs are highly prevalent, strongly associated with poor childhood and adult health, mental health, behavioral and social outcomes and demonstrate a pattern of high rates of intergenerational transmission.

When any one of us experiences something scary or threatening, our brains and bodies activate our stress response which leads to the production of high levels of stress hormones including adrenaline and cortisol and is responsible for many of the feelings we associate with being terrified. The amygdala, the brain’s fear center, is activated and the prefrontal cortex, which is responsible for executive functioning including attention, judgement and impulse control, is inhibited.  Stress hormones stimulate our hearts to beat stronger and faster, raise blood pressure and blood sugar, and activate our immune system, among many other effects.  The stress response is a normal and, in fact, essential part of our biological evolution, and allows us to respond and adapt to challenging circumstances. 

However, severe, intense or prolonged adversity may lead to overactivity of a child’s stress response.  In addition, children require the nurturing care of a trusted adult and safe environments to shut off the stress response and restore normal functioning. Without these buffers, the biological stress response becomes overactive.  Children are uniquely vulnerable to the effects an overactive stress response because their brains and bodies are just developing. High levels of adversity, without the buffering protections of trusted caregivers and safe, stable environments, lead to changes in brain structure and function, how genes are read, functioning of the immune and inflammatory systems, and growth and development. These changes comprise what is now known as the toxic stress response.

ACEs and toxic stress represent an urgent public health crisis with wide-reaching health and societal impacts, from heart disease to homelessness.1-5 According to recent data, 62.3% of California adults have experienced at least one ACE, and 16.3% have experienced four or more ACEs (2011–2017 data).6

ACEs are strongly associated, in a dose–response fashion, with some of the most common and serious health and social conditions facing our society, including nine of the 10 leading causes of death in the United States, and with earlier mortality.1,7-11

In addition, ACEs are associated with our most pressing social problems, including learning, developmental, and behavior problems, high school noncompletion, unemployment, poverty, homelessness, and felony charges—1,8,9,12-18

A recent estimate based on 2013 expenditures revealed that ACEs cost California $112.5 billion overall annually ($10.5 billion in personal healthcare spending and $102 billion in years of productive life lost), and will cost over $1.2 trillion in the next 10 years. 3-5,19,20

The high prevalence of ACEs in California, along with the intergenerational accumulation of impacts for individuals, families, and communities, have resulted in a public health crisis, with the greatest impacts on already disadvantaged individuals and communities. The time to act on this crisis is now.

Association of ACEs with Leading Causes Deaths in the US

Leading causes of deaths in the U.S. (2017) Odds ratios for ≥ 4 ACEs (relative to no ACEs)
1. Heart Disease2.1
2. Cancer2.3
3. Accidents (unintentional injuries)2.6
4. Chronic lower respiratory disease3.1
5. Stroke2.0
6. Alzheimer's disease or dementia11.2
7. Diabetes1.4
8. Influenza and pneumoniaunknown
9. Kidney disease1.7
10. Suicide (attempts)37.5

The extensive body of literature on the impacts of ACEs meets the Bradford Hill criteria for establishing likely causality (cause-and-effect) from observational data.12,13

roadmap resilence pdf.

Roadmap for Resilience: The California Surgeon General’s Report on Adverse Childhood Experiences, Toxic Stress and Health

Roadmap for Resilience: The California Surgeon General’s Report on Adverse Childhood Experiences, Toxic Stress and Health serves as a blueprint for how communities, states, and nations can recognize and effectively address Adverse Childhood Experiences (ACEs) and toxic stress as a root cause to some of the most harmful, persistent, and expensive societal and health challenges facing our world today. The report provides clear cross-sector and equitable response solutions, models, and best practices to be replicated or tailored to serve community needs. This comprehensive report brings together ​insights from global experts across sectors, specialties, and disciplines to promote science-based approaches to primary, secondary, and tertiary prevention strategies for ACEs and toxic stress. The report further specifies a sector-specific and cross-sector roadmap for addressing ACEs and toxic stress at the state level, prioritizing prevention, ​early detection, evidence-based interventions and equity in outcomes, ​highlighting the need for enhanced coordination across the following sectors: Healthcare; Public health; Social services; Early childhood; Education; and Justice.

About ACEs Aware initiative

The Office of the California Surgeon General and the California Department of Health Care Services (DHCS) are leading a first-in-the-nation statewide effort to screen children and adults for Adverse Childhood Experiences (ACEs) in primary care, and to treat the impacts of toxic stress with trauma-informed care. The ACEs Aware initiative is built on the consensus of scientific evidence demonstrating that early detection and evidence-based intervention improve outcomes. The bold goal of this initiative is to reduce ACEs and toxic stress by half in one generation, and to launch a national movement to ensure everyone is ACEs Aware.

All providers are encouraged to receive training to screen patients for ACEs. By screening for ACEs, providers can better determine the likelihood a patient is at increased health risk due to a toxic stress response, which can inform patient treatment and encourage the use of trauma-informed care. Detecting ACEs early and connecting patients to interventions, resources, and other supports can improve the health and well-being of individuals and families.

Beginning on January 1, 2020, DHCS began paying Medi-Cal providers $29 per trauma screening for children and adults with Medi-Cal coverage. Providers must self-attest that the training has been completed to be eligible to continue receiving Medi-Cal payment for conducting ACEs screenings. Additional details about the healthcare provider training and ACEs Aware Initiative are available at

ACEs Aware

  • ACEs Aware Resources for COVID-19 & Stress: ACEs Aware supports health care providers, their teams, and all those on the front lines of administering care and interventions as California addresses stress and anxiety related to COVID-19.
  • The newly launched ACEs Aware Provider Directory offers patients a way to find and connect with trained ACEs Aware providers throughout California.

The term Adverse Childhood Experiences (ACEs) comes from the landmark 1998 study by the Centers for Disease Control and Prevention (CDC) and Kaiser Permanente. (1) (2) It describes 10 categories of adversities in three domains experienced by age 18 years:

  • Abuse: physical, emotional, or sexual
  • Neglect: physical or emotional
  • Household dysfunction: growing up with household incarceration, mental illness, substance dependence, parental separation or divorce, or intimate partner violence

Data show that 62% of California residents have experienced at least one ACE and 16% have experienced four or more ACEs, using 2011-2017 Behavioral Risk Factor Surveillance System (BRFSS) data from a random-digit-dialed telephone survey. (3)

Key findings of the ACE Study and subsequent body of research include:

  1. ACEs are highly prevalent. Two thirds of respondents in the ACE Study reported at least one ACE and one in eight reported four or more ACEs. Subsequent studies have shown a rate of four or more ACEs that is closer to one in six. (4) (5)
  2. ACEs are strongly associated, in a dose-response fashion, with some of the most common and serious health conditions facing our society today, including at least nine of the 10 leading causes of death in the U.S. (6) (7)
  3. ACEs affect all communities. The original ACE Study was conducted among a population that was mostly Caucasian, middle class, employed, college educated, and privately insured. Subsequent studies have found higher prevalence rates of ACEs in people who are low-income, of color, justice-involved, and/or part of the lesbian, gay, bisexual, transgender, and queer (LGBTQ+) community. (8) (9) (10) (11) (12)

Several decades of scientific research have identified the biological mechanisms by which early adversity leads to increased risk of negative health and social outcomes through the life course. Repeated or prolonged activation of a child’s stress response, without the buffering protections of trusted, nurturing caregivers and safe, stable environments, leads to long-term changes in the structure and functioning of the developing brain, metabolic, immune, and neuroendocrine responses, and even the way DNA is read and transcribed. This is known as the toxic stress response. (13) (14) (15) (16)

These biological changes play an important role in the clinical progression from ACE exposure to negative short- and long-term health and social outcomes. Further, both the disrupted biology and the associated negative outcomes demonstrate a pattern of high rates of intergenerational transmission. Development of the toxic stress response is influenced by a combination of cumulative adversity, buffering or protective factors, and predisposing vulnerability.

In addition to ACEs, social determinants of health (SDOH), such as poverty, discrimination, and housing and food insecurity, are associated with health risks and may also be risk factors for toxic stress. While validated odds ratios are available in large, population-based studies utilizing the 10 standardized ACE criteria, the strengths of associations between SDOH and health outcomes have not been similarly standardized.

ACEs are associated with increased risk of a wide range of health conditions in both pediatric and adult populations. The life expectancy of individuals with six or more ACEs is 19 years shorter than that of individuals with none. (17)

These ACE-Associated Health Conditions include:

  • Pediatric Health: The effects of toxic stress are detectable as early as infancy. In babies, high doses of adversity are associated with failure to thrive, growth delay, sleep disruption and developmental delay. School-aged children may have increased risk of viral infections, pneumonia, asthma and other atopic diseases, as well as difficulties with learning and behavior. Among adolescents with high ACEs, somatic complaints – including headache and abdominal pain, increased engagement in high-risk behaviors, teen pregnancy, teen paternity, sexually transmitted infections (STIs), mental health disorders, and substance use – are common.
  • Adult Health: ACEs are associated with some of the most common and serious health conditions facing our communities. (18) People with 4 or more ACEs are:
    • 37.5 x as likely to attempt suicide (19)  
    • 3.2 x as likely to have chronic lower respiratory disease (20)
    • 2 to 2.3 x as likely to have a stroke, (21)  cancer, (22) or heart disease (23)
    • 1.4 as likely to have diabetes (24)

The higher the ACE score, the greater the risk for ACE-Associated Health Conditions.

  • Mental and Behavioral Health: The higher the ACE score, the greater the likelihood an individual may experience mental health disorders such as depression, post-traumatic stress disorder, anxiety, and sleep disorders, and to engage in risky behaviors such as early and high-risk sexual behaviors and substance use. (25) (26) High doses of childhood adversity are associated with increased risk of engaging in high-risk behaviors that can lead to negative health outcomes.

However, even in the absence of health-damaging behavior, strong associations between cumulative childhood adversity and increased risk of serious health conditions persist. Evidence suggests that the toxic stress response likely plays a role in mediating both behavior-related and non-behavior-related pathways.

  1. Hughes K, Bellis MA, Hardcastle KA, et al. The effect of multiple Adverse Childhood Experiences on health: A systematic review and meta-analysis. The Lancet Public Health 2017; 2(8): e356–e66.
  2. Roos LE, Mota N, Afifi TO, Katz LY, Distasio J, Sareen JJAJoPH. Relationship between Adverse Childhood Experiences and homelessness and the impact of axis I and II disorders. 2013; 103(S2): S275-S81.
  3. Miller TR, Waehrer GM, Oh DL, et al. Adult health burden and costs in California during 2013 associated with prior Adverse Childhood Experiences. PloS One 2020; 15(1): e0228019.
  4. Waehrer GM, Miller TR, Silverio Marques SC, Oh DL, Burke Harris N. Disease burden of Adverse Childhood Experiences across 14 states. PloS One 2020; 15(1): e0226134.
  5. Bellis MA, Hughes K, Ford K, Ramos Rodriguez G, Sethi D, Passmore J. Life course health consequences and associated annual costs of Adverse Childhood Experiences across Europe and North America: A systematic review and meta-analysis. The Lancet Public Health 2019; 4(10): e517–e28.
  6. California Department of Public Health, Injury and Violence Prevention Branch (CDPH/IVPB), California Department of Social Services, Office of Child Abuse Prevention, California Essentials for Childhood Initiative, University of California Davis, Violence Prevention Research Program, Firearm Violence Research Center. Adverse Childhood Experiences data report: Behavioral Risk Factor Surveillance System (BRFSS), 2011-2017: An overview of Adverse Childhood Experiences in California. California: California Department of Public Health and the California Department of Social Services, 2020.
  7. Centers for Disease Control and Prevention. Ten leading causes of death and injury, United States, 2017. 2017.
  8. Merrick MT, Ford DC, Ports KA, et al. Vital signs: Estimated proportion of adult health problems attributable to Adverse Childhood Experiences and implications for prevention—25 states, 2015–2017. Morbidity and Mortality Weekly Report 2019; 68(44).
  9. Center for Youth Wellness. A hidden crisis: Findings on Adverse Childhood Experiences in California: Center for Youth Wellness, 2014.
  10. Brown DW, Anda RF, Tiemeier H, et al. Adverse Childhood Experiences and the risk of premature mortality. American Journal of Preventive Medicine 2009; 37(5): 389-96.
  11. Petruccelli K, Davis J, Berman T. Adverse Childhood Experiences and associated health outcomes: A systematic review and meta-analysis. Child Abuse & Neglect 2019; 97: 104127.
  12. Jäggi LJ, Mezuk B, Watkins DC, Jackson JS. The relationship between trauma, arrest, and incarceration history among Black Americans: Findings from the National Survey of American Life. Society and Mental Health 2016; 6(3): 187-206.
  13. Giovanelli A, Reynolds AJ, Mondi CF, Ou S-R. Adverse Childhood Experiences and adult well-being in a low-income, urban cohort. Pediatrics 2016; 137(4): e20154016.
  14. Cheng TL, Johnson SB, Goodman E. Breaking the intergenerational cycle of disadvantage: The three generation approach. Pediatrics 2016; 137(6).
  15. Burke NJ, Hellman JL, Scott BG, Weems CF, Carrion VG. The impact of Adverse Childhood Experiences on an urban pediatric population. Child Abuse & Neglect 2011; 35(6): 408-13.
  16. Metzler M, Merrick MT, Klevens J, Ports KA, Ford DC. Adverse Childhood Experiences and life opportunities: Shifting the narrative. Children and Youth Services Review 2017; 72: 141-9.
  17. Danese A, Moffitt TE, Harrington H, et al. Adverse Childhood Experiences and adult risk factors for age-related disease: Depression, inflammation, and clustering of metabolic risk markers. Archives of Pediatrics & Adolescent Medicine 2009; 163(12): 1135–43.
  18. Poulton R, Moffitt TE, Silva PA. The Dunedin Multidisciplinary Health and Development Study: Overview of the first 40 years, with an eye to the future. Social Psychiatry and Psychiatric Epidemiology 2015; 50(5): 679-93.
  19. Fang X, Brown DS, Florence CS, Mercy JA. The economic burden of child maltreatment in the United States and implications for prevention. Child Abuse & Neglect 2012; 36(2): 156-65.
  20. Safe & Sound. The economics of child abuse: A study of California: Safe & Sound, 2019.