What are the early‑childhood adverse childhood experiences (ACEs) that occur before age 5?

Early Childhood Adverse Childhood Experiences (ACEs)

Early childhood ACEs are potentially traumatic events occurring before age 5 that fall into three main categories: abuse (physical, emotional, sexual), neglect (physical, emotional), and household dysfunction (caregiver substance abuse, mental illness, divorce/separation, incarceration, domestic violence). 1

Core Categories of Early Childhood ACEs

Abuse-Related ACEs

• Physical abuse: Bodily harm inflicted by a caregiver 1
• Emotional abuse: Psychological maltreatment including verbal aggression, humiliation, or threats 1
• Sexual abuse: Any sexual contact or exploitation by an adult or older child 1

Neglect-Related ACEs

• Physical neglect: Failure to provide basic needs such as food, shelter, clothing, or medical care 1
• Emotional neglect: Failure to provide emotional support, love, or attention 1

Household Dysfunction ACEs

• Intimate partner violence: Witnessing violence between caregivers in the home 1
• Parental substance abuse: Living with a caregiver who has alcohol or drug problems 1
• Parental mental illness: Living with a caregiver who has depression, anxiety, or other mental health conditions 1
• Caregiver death or separation: Loss of a parent through death, divorce, or abandonment 1
• Caregiver incarceration: Having a parent or guardian who is detained or imprisoned 1

Additional Traumatic Experiences in Early Childhood

Community and External Traumas

• Community violence: Exposure to neighborhood violence, shootings, or gang activity 1
• Natural disasters: Experiencing hurricanes, floods, fires, or other catastrophic events 1
• Unintentional injuries: Serious accidents requiring medical intervention 1
• Terrorism exposure: Direct or indirect exposure to terrorist acts 1
• Immigrant or refugee traumas: Including detention, discrimination, or forced displacement 1
• Racism and discrimination: Systemic and interpersonal experiences of racial bias 1

Medical Traumas

• Invasive medical procedures: Surgeries, repeated hospitalizations, or painful treatments 1
• Serious injuries: Trauma requiring emergency or intensive medical care 1

Prevalence in Early Childhood

Approximately 27% of children aged 0-5 experience one ACE, 17% experience two ACEs, 11% experience three ACEs, and 11% experience four or more ACEs. 2

Critical Developmental Considerations

Why Early Childhood Matters

• Brain vulnerability: The developing brain from birth to age 5 is particularly susceptible to toxic stress from ACEs, with effects at the molecular, cellular, and organ level 1
• Foundational period: Early childhood represents the most critical window for establishing healthy stress-response systems and attachment relationships 1
• Cumulative impact: ACEs occurring before age 5 set the stage for lifelong health trajectories affecting physical, emotional, developmental, and behavioral outcomes 1

Screening Considerations for Children Under 5

The standard 10-item ACE questionnaire was designed for retrospective adult reporting and is not validated for direct use with young children; instead, screening should assess current exposures through parent report or home observation. 2

Practical Screening Approach

• Use proxy measures: Screen for current risk factors that predict ACE development rather than explicit abuse or neglect 2
• Home environment assessment: Evaluate safety hazards, secondhand smoke exposure, and household stressors 2
• Preventive care utilization: Monitor patterns of missed well-child visits or overuse of emergency services as red flags 2
• Developmental screening: Children with four or more ACEs show increased risk for developmental delays and chronic health conditions even before age 5 2

Important Caveats

The original 10-item ACE framework underestimates total adversity because it omits poverty-related stressors, bullying, community violence, and systemic racism—all of which can be traumatic for young children. 3

Almost one-half of American children (34 million under age 18) have experienced at least one potentially traumatic early childhood experience, making ACEs a public health emergency requiring universal trauma-informed approaches. 1