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.
The ACEs study participants were asked to report whether they had experienced physical/sexual/emotional abuse, physical/emotional neglect, exposure to domestic violence, household substance abuse, household mental illness, parental separation/divorce, and incarcerated household members. Two-thirds of participants reported at least one ACE, and more than 1 in 5 reported ≥3 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
- 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
- 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.
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 related stress can also cause epigenetic changes that alter how genes are expressed, and these changes can also be passed to fetuses.
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.
You can find more details on the CDC’s Adverse Childhood Experiences study page.