The ACE Study: How Childhood Trauma Impacts Lifelong Health

The Adverse Childhood Experiences Study (ACE Study) is one of the most influential public health studies ever conducted. It was the product of a collaboration between Vincent J. Felitti, MD, founder of the Preventive Medicine Department at Kaiser Permanente in San Diego, and Robert F. Anda, MD, MS of the National Centers for Disease Control and Prevention (CDC).

Together, they designed, analyzed, and published groundbreaking research showing the long-term health impacts of childhood abuse, neglect, and household dysfunction.

The Power of Listening to People’s Stories

Dr. Anda reflected:

“The most important thing that contributes to the information of the ACE Study is simply the powerful nature of when people tell you the truth about their lives, and you listen, you understand their life course.”

This realization changed how physicians, therapists, and policymakers understand adult health:

• Many of the problems seen in adult medicine are rooted in unseen issues from childhood.
• The ACE Study revealed just how widespread—and costly—the effects of trauma really are.

ACE and Public Health

The ACE Study changed the landscape because it showed that childhood trauma is not just a “social work” or “psychology” issue. It is a public health crisis.

The pervasiveness of ACEs has been linked to:

• Depression
• Substance abuse
• Sexually transmitted infections
• Cancer
• Heart disease
• Chronic lung disease
• Diabetes

As ACE scores increase, so does the risk of these major health issues.

The Numbers Are Staggering

• If an individual scores four or higher on the ACE test, the likelihood of chronic depression rises to about 60% in women and 35% in men.
• Smoking patterns were almost identical whether measured in the Kaiser health plan or in the general population, showing that ACE findings apply across communities.
• The ACE Study even helps explain how people with no conventional risk factors can still end up with coronary disease—trauma leaves a lasting imprint on the body and mind.

The ACE Study and Intergenerational Trauma

Over an eight-year period, ACE research was used with 440,000 adult patients. The findings revealed something critical:

“This is the most important thing you can ever do—begin to deal with the intergenerational transmission of adversity that causes so many problems in our society.” — Dr. Felitti

The ACE Study shows that unhealed trauma is passed down, shaping not just individual health but entire communities and future generations.

Why the ACE Study Matters Today

The ACE Study reframed how we understand trauma. It connected childhood experiences with adult physical and mental health outcomes, proving that what happens in childhood doesn’t just “go away.” It stays in the body, the mind, and sometimes gets carried forward into the next generation.

Understanding ACEs gives us the tools to:

• Break cycles of trauma
• Prevent lifelong health problems
• Support resilience and healing

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