The Adverse Childhood Experiences (ACE) study

The Adverse Childhood Experiences (ACE) study (Felliti et al, 1998) was one of the largest investigations ever to assess the association between childhood maltreatment and later health and well-being. It began in the 1980’s, when Dr Vincent Felliti (from Kaiser Permanente’s Health Appraisal Clinic in San Diego) became exasperated by the high drop-out rates in his obesity clinic, despite evidence of significant weight loss. He stumbled upon a link between the development of obesity and childhood sexual abuse. He collaborated with Dr Robert Anda, a researcher from the Centres for Disease Control & Prevention to carry out a study to explore the association between childhood experiences and health throughout life. The study involved over 17,000 people. They were asked about their health history as well as their childhood experiences, specifically the following:

The results of this research was shocking in many ways:

1.    ACEs were found to be common:

2.   The more ACEs experienced by an individual in childhood, the greater the risk of developing a range of mental, social and physical health issues as an adult. Those who had experienced 4 or more ACEs were more likely to experience health problems or engage in health risk behaviours:

They were more likely to have experienced or perpetrated violence and to have been in prison:

The study also found that, on average, people with 6 or more ACEs die 20 years earlier than those with none. How does adversity lead to these outcomes? Exposure to persistently high levels of stress causes physiological changes to the brain and body and can lead to self-soothing behaviours, such as smoking and substance misuse, which compromise health and well-being.

Participants in the original ACE study were mostly white, middle class and college educated adults. Paediatrician Nadine Burke Harris (2011) carried out research with her patients in a socially deprived area of San Francisco. One of the findings was that children with 4 or more ACEs were more than 32 times more likely to have learning and behaviour problems in school than those who had none.

The original ACE study has been replicated internationally. National ACE studies have been carried out in England and Wales and in some local districts. The English study (Bellis et al, 2014) found that almost half (46%) of the adult population in England had at least 1 ACE, while 8% had 4 or more. As in the USA, there was a strong link between number of ACEs and health outcomes. Individuals with 4 or more ACEs were 3 times more likely to smoke, 7 times more likely to have been involved in violence in the past year and 11 times more likely to have ever been in prison.

The Welsh study (Bellis et al, 2015) found that almost half (47%) of the adult population in England had at least 1 ACE, while 14% had 4 or more. It found that individuals with 4 or more ACEs were 4 times more likely to be a high risk drinker, 6 times more likely to be a smoker, 16 times more likely to be a crack cocaine or heroin user, 15 times more likely to have been involved in violence in the past year and 20 times more likely to be in prison during their lives.

While there has been no Northern Ireland ACE study, an ACE prevalence study was carried out with Queens University students (Spratt and McGavock, 2014) to explore the link between prevalence of ACEs in the University population and contact with Social Services. More than half the study population (56%) reported at least 1 ACE, with 12% reporting an ACE score of 4 or more.


Bellis, M. A., Hughes, K., Leckenby, N., Perkins, C. and Lowey, H. (2014) ‘National Household Survey of adverse childhood experiences and their relationship with resilience to health-harming behaviours in England’. BMC Medicine. 12(72).

Bellis, M. A., Ashton, K., Hughes, K., Ford, K., Bishop, J., and Paranjothy, S. (2015) Adverse Childhood Experiences and their impact on health-harming behaviours in the Welsh adult population. Cardiff: Public Health Wales.

Burke, N. J., Hellman, J. L., Scott, B. J., Weems, C. F. and Carrion, V. C. (2011) “The Impact of Adverse Childhood Experiences on an Urban Paediatric Population,” Child Abuse and Neglect 35 (6).

Felitti, M. D., Anda, R. F., Nordenberg, M. D. et al (1998) ‘Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults: The Adverse Childhood Experiences (ACE) Study’ American Journal of Preventative Medicine. 14.

Spratt, T., McGavock, L. (2014) ‘Prevalence of Adverse Childhood Experiences in a University Population: Associations with Use of Social Services’. British Journal of Social Work. 44 (3).