Adverse childhood experiences (ACEs) are potentially traumatic events that occur before a child reaches the age of 18. Such experiences can interfere with a person’s health, opportunities and stability throughout his or her lifetime—and can even affect future generations. Some policymakers are interested in preventing adverse experiences, mitigating their effects and reducing the associated costs to state health care, education, child welfare and correctional systems. This webpage presents research and resources, as well as state strategies aimed at preventing and reducing the occurrence and negative consequences of ACEs.
Read the NCSL brief | Preventing and Mitigating the Effects of Adverse Childhood Experiences
What Are ACEs?
Adverse childhood experiences (ACEs) are potentially traumatic events that occur during childhood. The Centers for Disease Control and Prevention (CDC) and Kaiser Permanente conducted the first ACE study from 1995 to 1997 and asked more than 17,000 adults about childhood experiences including emotional, physical and sexual abuse; neglect; and household challenges of parental separation, substance abuse, incarceration, violence and mental illness. Nearly two-thirds of participants noted at least one ACE and more than 1 in 5 noted three or more. Researchers identified a link between ACE exposure and a higher likelihood of negative health and behavioral outcomes later in life, such as heart disease, diabetes and premature death.
Moreover, ACEs can follow an intergenerational pattern. For example, research suggests that children who experience physical abuse may be more likely to commit violence, including abusing or neglecting their own children, and to be revictimized in the future. ACEs align with a shifting public health focus to upstream thinking and the prevention of negative behaviors and outcomes before they occur.
Since the original study, the list of ACEs in various measures has expanded with the goal of capturing diverse population data, particularly from children of color and those living in poverty. For instance, since 2011, ACEs questions on the National Survey of Children’s Health (NSCH) have incorporated familial death, neighborhood violence, economic hardship and unfair treatment based on race or ethnicity.
What Are the Consequences of ACEs?
To the Individual
The original ACE study and decades of research since have linked ACEs to an increased risk of developing chronic diseases and behavioral challenges, including obesity, autoimmune disease, depression and alcoholism. The greater the number of ACEs, the greater the risk for negative outcomes. Individuals with multiple ACEs may be more likely to perform poorly in school, be unemployed and develop high-risk health behaviors, such as smoking and drug use. These high-risk behaviors account for nearly 50 percent of the increased risk of negative consequences associated with ACEs. In 2019, the CDC found that at least five of the top 10 leading causes of death, including respiratory and heart disease, cancer and suicide, are associated with ACEs.
The underlying mechanisms by which ACEs exert their effects on health are through the development of toxic stress, a prolonged or excessive activation of the stress response system. Nearly all people experience stress, such as the stress felt before an important test or job interview. However, chronic stress sustained over time can be damaging to the body and the brain, particularly for children, because the earliest years are a critical time for development. The accumulation of excessive stress in the body interferes with the development of healthy neural, immune and hormonal systems and can alter the expression of our DNA. Multiple ACEs over time—especially without adequate adult support—can affect the nervous, endocrine and immune systems, and have lasting effects on attention, behavior, decision-making and response to stress throughout a lifetime.
Fortunately, researchers have identified strategies to avoid negative outcomes by preventing ACEs, some of which are identified in policy implications. The CDC estimates ACEs prevention could reduce chronic conditions, risk behaviors, socioeconomic challenges and leading causes of death in the United States.
Potential Reduction of Negative Outcomes in Adulthood
There are also certain factors that can help mitigate long-term negative impacts after ACEs have already occurred and strengthen the ability to overcome adversity, often referred to as resilience. Protective factors, such as strong family bonds, cultivate greater resilience that can help protect children from the detrimental effects of adverse experiences. Safe, stable and nurturing relationships and communities help to build resilience, prevent violence, improve mental health and support health across one’s lifespan.
To State Budgets
The prevalence of ACEs and their association with various negative outcomes can create high costs. For example, one study estimates that the lifetime economic burden of substantiated child abuse and neglect, which account for half of the original 10 ACEs, is approximately $401 billion. This amount reflects productivity losses for employers and health care, education, child welfare and corrections systems costs for states.
How Common Are ACEs?
The latest National Survey of Children’s Health data shows in 2017-18, excluding economic hardship, approximately 30 percent of children experienced one ACE, and about 14 percent experienced two or more. According to a 2018 Child Trends brief, including a measure of economic hardship, about 45 percent of children have experienced at least one ACE. Parental separation and economic hardship are the most common ACEs regardless of race and ethnicity, though children of different races and ethnicities do not experience ACEs equally.
National percentages of children experiencing at least one ACE include:
61 percent non-Hispanic Black children
51 percent Hispanic children
40 percent non-Hispanic white children
23 percent non-Hispanic Asian children
In 2019, CDC scientists analyzed data from more than 144,000 adults in 25 states and found that 61 percent of them experienced at least one ACE. Nearly 16 percent of adults have experienced four or more ACEs, and women and several racial and ethnic minority groups are at greater risk for experiencing a higher number of ACEs.
In the two decades since the original ACE study, many publications have added to the body of research on childhood trauma, including effective strategies to prevent and manage negative consequences. For example, many of the recommendations for achieving strong physical health—adequate sleep, good nutrition and regular exercise—are also useful for protecting children from the harms of ACEs. Efforts that focus on building healthy families early in life are cited as significant means to prevent ACEs and reduce their damaging effects. Social support and stress reduction strategies, such as mindfulness and psychotherapy, are also well supported.
The CDC developed a resource tool focused on preventing ACEs that highlights evidence-based approaches. These approaches include strengthening economic supports for families; promoting social norms that protect against violence and adversity; ensuring a strong start for children; teaching skills; connecting youth to caring adults and activities; and intervening to lessen immediate and long-term harms. Many of these strategies are explored below. State policies may include strategies to help parents reduce stress, build resilience in children and families, and increase screening and treatment for ACEs.
Know the Data
The Behavioral Risk Factor Surveillance System (BRFSS), an annual phone survey administered by the CDC, collects state data on health-related risk behaviors, chronic health conditions and the use of preventive services. Each year, residents in 50 states, the District of Columbia and three U.S. territories complete the survey. Since 2009, 42 states and the District of Columbia. have included ACEs questions in their BRFSS survey for at least one year, making it a tool for identifying state-specific trends in ACEs.
Support Parental Stress Reduction
Nearly a quarter of U.S. children live below the federal poverty level, and in almost every U.S. state, economic hardship is one of the most common ACEs. Economic hardship affects children because it can cause high parental stress and increase the likelihood of kids experiencing abuse or neglect. Efforts to strengthen families’ economic security may help reduce parental stress, establish greater household stability and protect children. Policies such as earned income tax credits, minimum wage increases and full pass-through child support payments, according to research, are some mechanisms for reducing ACEs.
Some strategies may include:
Earned Income Tax Credit (EITC)
The EITC is a policy the federal government, some states, the District of Columbia and some municipalities have implemented to support the economic security of low-income working families, especially those with children. Learn more about the EITC and state examples on NCSL’s webpage Tax Credits for Working Families: Earned Income Tax Credit.
NCSL tracks state minimum wages and legislation here.
Child support is the payment by a parent to support a child or children of whom he or she does not have full custody. All states and territories operate a child support enforcement program. NCSL provides comprehensive information on child support policy issues on the Child Support Overview webpage.
Two-generation strategies simultaneously address the needs of parents and children to improve outcomes for the whole family. States approach two-generation strategies through programs focused on children, on parents and on supporting family economic success (for example, New England's Whole Family Approach to Jobs initiative). Learn more from NCSL’s Two-Generation Strategies Toolkit.
Federal Nutrition Programs
The U.S. Department of Agriculture administers various programs and services that increase food security and reduce hunger through access to nutrition education and affordable, healthy food, such as:
Paid Family or Sick Leave
Paid family leave provides compensation for extended time away from work for specified family and medical reasons, such as the birth of a child or to care for a family member with a serious health condition. Paid sick leave provides compensation for time off related to personal medical care.
The Center on the Developing Child at Harvard University offers three principles for policymakers to consider in helping families with young children thrive: enhancing responsive relationships, strengthening core life skills and reducing sources of stress. These principles target characteristics of the individual, family and community that are associated with physical health. Strategies that expand access to quality early child care and education, and that increase positive parenting skills and safe, stable and nurturing relationships, can strengthen protective factors and improve lifelong health.
Home visiting programs employ nurses, social workers, early childhood educators and other trained professionals to visit families in their homes during pregnancy and early childhood. These programs teach positive parenting skills (including best practices for coping with stress), provide health education and connect families to supportive services.
Home visiting is linked to improved school readiness, higher quality parenting, more positive child-parent interactions and improvements in parents’ mental health as they develop more responsive connections to their children. Home visiting reduces the likelihood of abuse and neglect.
The Maternal, Infant and Early Childhood Home Visiting (MIECHV) program, a federal initiative, provides states with substantial resources for home visiting. For more information, read NCSL’s brief on early childhood home visiting.
In 2019, Oregon enacted SB 526
to direct the state Health Authority to design, implement and maintain a voluntary statewide program to provide universal newborn nurse home-visiting services to all families to support healthy child development and strengthen families.
Utah passed the Nurse Home Visiting Pay-for-Success Program (SB 161
) in 2018 to create an evidence-based nurse home-visiting program.
Quality Early Child Care and Education
In addition to building secure attachments with caring adults, access to early childhood education is a promising pathway to resilience. Early learning opportunities allow children to think, play and explore, which exercise critical executive functions such as “working memory” and self-regulation. Early childhood education supports social and emotional development, which includes building self-confidence and positive relationships. It also instills in children the motivation, persistence and other life skills necessary to be inventive, flexible and functional adults, and to be resilient in the face of life’s challenges.
Increase Screening and Treatment
Approximately 27 percent of U.S. children experience a diagnosable mental or behavioral disorder, such as depression, anxiety or attention-deficit/hyperactivity disorder (ADHD). For people with ACEs, the likelihood of developing one or more of these disorders is significantly greater. Frequent classroom interruptions, aggression, underperformance, truancy, poor attitude, bullying and social withdrawal are symptoms commonly expressed by children struggling to manage a learning or behavioral issue.
Schools and child care centers are uniquely positioned to detect these issues early and link children to supportive services and formal assessments. Early interventions may mitigate the direst consequences of childhood trauma and frequently demonstrate positive effects on long-term health. Specifically, efforts by schools and child care settings to consider a child’s history of trauma and subsequent coping strategies—an approach commonly called trauma-informed care—are likely to be highly valuable in mitigating some of the consequences of ACEs.
Children who grow up in households with family members with an untreated substance use disorder (SUD) or mental illness often witness significant dysfunction. Efforts to provide comprehensive health services may support better SUD treatment, mental health and child welfare outcomes.
- In 2019, Hawaii lawmakers implemented a task force to evaluate certain students experiencing challenges using an ACEs assessment protocol and to make recommendations regarding a statewide implementation of that protocol.
- In 2018, Missouri passed a law to establish the Trauma Informed Care Task Force to promote comprehensive trauma-informed support systems and interagency cooperation.
- In 2017, Indiana lawmakers established an opioid addiction recovery pilot program to assist expectant mothers with an opioid addiction. The program provides treatment in a residential care facility and home visitation services following discharge from the facility.
- Nineteen states have either created or funded drug treatment programs specifically for pregnant women, and 17 states and the District of Columbia provide pregnant women with priority access to state-funded drug treatment programs.
Since 2015, at least 30 states and the District of Columbia have enacted or adopted legislation related to ACEs, including laws that address childhood trauma, child adversity, toxic stress or ACEs specifically. Many of these bills create a new taskforce or work group, implement training for educators and others on ACEs or trauma-informed practices, or strengthen behavioral health supports for children. You can explore 50-state ACEs and child maltreatment legislation in NCSL’s Injury Prevention Database.
A study published in 2019 explored legislator perspectives on ACEs. Twenty-four South Carolina legislators identified several factors that can influence related policy, including:
- Increasing awareness of ACEs
- Filling gaps in understanding about what can be done about ACEs
- Using data and stories that contextualize the problem of ACEs
- Capitalizing on the bipartisanship of children's issues
- Linking to current ACEs-related issues on the policy agenda (e.g., school safety, violence prevention and the opioid epidemic).
This seminar includes four presentations that teach how toxic stress affects the developing brain and body. It discusses the latest discoveries on the changes that take place in a new parent’s brain to support positive parenting—and the implications when these changes are diminished due to a health condition or trauma. The speakers explore evidence-based policy options such as home visiting programs and efforts that address health screening and treatment, family economic security, parental stress and family protective factors.
This 2018 NCSL Legislative Summit presentation highlights information from Zero to Three, a nonprofit organization that educates the public and political leaders about the unique developmental needs of babies and toddlers, and Child Trends, a nonprofit research center focused on children, families, child well-being and factors affecting children’s lives.
Did you know that more than 1 million new neural connections are formed every second in the first few years of a child’s life? This 2017 webinar highlights brain research and the science behind the critical development taking place. Learn about policy opportunities to help mitigate the effects of toxic stress and support healthy development, which can result in better outcomes for our youngest children and their families. PowerPoint Presentation | PDF file, 56 pages
Adverse childhood experiences are potentially traumatic events, such as abuse or neglect, that can have negative, lasting effects on health and well-being. This 2018 webinar explores the connection between ACEs and the opioid epidemic. Speakers discussed how ACEs can affect later substance misuse, including the intergenerational impacts on families. Experts and legislators highlight potential policy options and innovative state strategies. PowerPoint Presentation | PDF file, 35 pages
On this episode of “Our American States,” an NCSL podcast, we explore two critical components of a child’s development. First, we address adverse childhood experiences, which are stressful or traumatic events in childhood that can have long-term impacts on health and well-being. We talk to Nadine Burke Harris, a national policy expert, who walks through research on childhood trauma and provides policymakers with ideas to address families facing stresses that cause ACEs. We also discuss the importance of positive brain development, discover why the first three years are so critical for the nurturing of children, go over key research and find out what the policy implications are regarding early brain development.
Nadine Burke Harris is a pediatrician who in 2019 became the first surgeon general of California. She began noticing disturbing trends as she treated children in an underserved neighborhood in San Francisco: Many of the kids who came to see her had experienced childhood trauma. She began studying how childhood exposure to adverse events affects brain development and one’s health as an adult. Harris presented to NCSL’s Legislative Summit in 2017, along with state legislators from South Dakota and Tennessee who discussed their work on preventing and mitigating the effects of ACEs.