The Lasting Impact of Adverse Childhood Experiences

Adverse childhood experiences pyramid of effects on health and well-being throughout lifespan

The Adverse Childhood Experiences (ACEs) study was a landmark research trial conducted by Kaiser Permanente and the U.S. Center for Disease Control. The study examined the correlation between adverse experiences in childhood and health outcomes in adulthood, and it clearly showed just how profound that connection is.

What are adverse childhood experiences?

Adverse childhood experiences that can negatively affect health outcomes include:

  • Physical abuse
  • Sexual abuse
  • Emotional abuse
  • Physical neglect
  • Emotional neglect
  • Exposure to domestic violence
  • Household substance abuse
  • Household mental illness
  • Parental separation/divorce
  • Incarcerated household members

Over 60% of participants in the ACEs study reported at least one ACE, and more than 1 in 5 reported ≥3 ACEs.

ACEs Aware has an ACE screener here. Scoring is based on the number of different types of ACEs an individual has experienced rather than the number of instances of exposure to each kind of ACE. They identify the following risk categories:

  • Low risk: score of 0 in children / score of 0-3 without associated health conditions in adults
  • Intermediate risk: score of 1-3 without associated health conditions in children / score of 1-3 with associated health conditions in adults
  • High risk: score of 1-3 with associated health conditions or a score of 4+ in children / score of 4+ in adults

Impact of ACEs

The results of the ACEs study showed a dose-response curve between the number of ACEs and the risk of adult health problems (i.e. a higher number of ACEs was associated with a higher number of health complications). ACEs were associated with the following negative outcomes and high-risk activities associated with negative health outcomes:

  • Alcoholism and alcohol abuse
  • Chronic obstructive pulmonary disease
  • Depression
  • Fetal death
  • Health-related quality of life
  • Illicit drug use
  • Ischemic heart disease
  • Liver disease
  • Poor work performance
  • Financial stress
  • Risk for intimate partner violence
  • Multiple sexual partners
  • Sexually transmitted diseases
  • Smoking
  • Suicide attempts
  • Unintended pregnancies
  • Early initiation of smoking
  • Early initiation of sexual activity
  • Adolescent pregnancy
  • Risk for sexual violence
  • Poor academic achievement

Not only are there a large number of negative effects, but also the magnitude of these effects is extremely disturbing. An ACEs score above six was associated with a 3000% increase in suicide and a life expectancy 20 years less than the population average. I think that one of the particularly important findings of the study was that the negative outcomes were not a simple cause-and-effect relationship with high-risk behaviours. The wide-ranging negative outcomes still occur with or without high-risk behaviours.

How these effects occur

ACEs are thought to affect the structural development of neural networks in the brain as well as biochemistry, including chemical messengers like cortisol and adrenaline.

The term “toxic stress” refers to the effects of excessive and long-lasting stress as a result of chronic over-activation of the body’s stress response systems. This stress can cause epigenetic changes that alter how genes are expressed, and these changes can also be passed to fetuses.

The ACEs pyramid at the top of the page shows how disrupted neurodevelopment due to ACEs can lead to social, emotional, and cognitive impairment, which can then lead to the adoption of high-risk health behaviours. This can result in disease, disability, social problems, and even early death.

Risk and protective factors

According to the CDC, these are some of the factors that make it more likely that someone will experience ACES:

  • families with caregiving challenges related to special needs children
  • caregivers experienced childhood abuse or neglect
  • low income
  • families with adults who have a low level of education
  • use of corporal punishment
  • inconsistent discipline or low levels of parental supervision
  • communities with high rates of violence, crime, poverty, or unemployment

Protective factors that reduce the risk of ACEs occurring include:

  • safe, stable, nurturing relationships at home
  • children with caring adults outside of the family
  • children’s basic food, shelter, and health service needs are met
  • caregivers with steady employment
  • communities with access to safe, stable housing
  • communities with access to nurturing and safe childcare, high-quality preschool, and after school programs


The CDC describes these systemic strategies to reduce ACEs:

  • Economic supports for families, including improved financial security (e.g. child support payments, tax credits, subsidized child care) and family-friendly work policies (e.g. livable wages, paid parental and sick leave, flexible and consistent schedules)
  • Supporting healthy social norms around parenting through education and approaches to reduce corporal punishment
  • High quality early childhood education
  • Enhance parenting skills through interventions like skills training and early childhood home visitation
  • Interventions to decrease harms and prevent further risk

I first heard about this study way back when I was in nursing school, and I remember wondering at the time why I hadn’t heard of something that important before then. I still think it’s something that more people need to be aware of, because it sheds so much light on the experiences of those who have lived through childhood trauma.

Lasting impacts of adverse childhood experiences: TBI, depression, unintended pregnancy, HIV, cancer, substance abuse
Centers for Disease Control

This TED Talk from pediatrician Dr. Nadine Burke Harris emphasizes the importance of preventing and treating early life trauma.

You can find more details on the CDC’s Adverse Childhood Experiences study page.

8 thoughts on “The Lasting Impact of Adverse Childhood Experiences”

  1. Learning about the ACE study is such an “aha!” moment for so many people! It’s such an important study, and its findings continue to be relevant for a wide range of services. Thank you for introducing your readers to this important piece of research.

  2. I wish there was more attention paid to these studies and help for people who have suffered an extraordinary amount of ACEs. I myself have a ton of them when I have gone through their list and counted. There should be more help for people who go through such things.

  3. Great summary. My boys are adopted and many of their difficulties are because of traumatic life experiences. One thing that stuck with me in adoption training was an image of a typical brain compared to a trauma brain, the trauma brain had huge gaps in it. Early life trauma can affect so much developmentally.

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