Adverse Childhood Experiences: Understanding Their Lasting Impact

Dr Laura Allen
Oct 31
9 min read

An image showing the possible impact of adverse childhood experiences.

This site contains product affiliate links. We may receive a small commission if you make a purchase after clicking on one of these links.

Adverse childhood experiences (ACEs) are one of the most important concepts in psychology, psychotherapy and public health. Originally identified in the 1990s, ACEs refer to traumatic events before the age of 18. Such events can include physical, psychological and sexual abuse, neglect and/or household dysfunction (Felitti et al., 1998).

Since then, the ACEs framework has shaped how clinicians, educators and policymakers approach early adversity. For example, under national safeguarding legislation, educational establishments are expected to have awareness of ACEs and know how to support effected children. In the UK, studies by Public Health Wales and NHS Scotland show ACEs are significant predictors of health inequality and poor life outcomes (Bellis et al., 2014; Public Health Wales, 2015).

Moreover, contemporary research in neuroscience and behavioural psychology consistently show a strong correlation between scoring high on the ACE test and an increased risk of developing a mental health disorder later in life.

Furthermore, in the works of renowned Stanford Professor of Evolutionary Biology, Robert M. Sapolsky, most notably Behave and Determined, evidence of ACE is consistent with low socio-economic status and high stress and anxiety. The consensus across all major public health organisations is clear: this is a near perfect recipe for an increased susceptibility of disease, disability and – ultimately – premature mortality.

It's for these reasons, and those enumerated below, why the many adverse impacts of ACE need to be better understood.

What are Adverse Childhood Experiences (ACEs)?

Young Mind (2018) define Adverse Childhood Experiences (ACEs) as “highly stressful, and potentially traumatic, events or situations that occur during childhood and/or adolescence.” They go on to inform us that an ACE can be caused by a “single event, or prolonged threats to, and breaches of, the young person’s safety, security, trust or bodily integrity.”

The term adverse childhood experiences was popularised by the Adverse Childhood Experiences Study conducted by the US Centres for Disease Control and Kaiser Permanente (Felitti et al., 1998). The study measured 10 categories of adversity, including physical, emotional and sexual abuse; emotional and physical neglect; and household challenges such as parental separation, substance misuse, domestic violence, or incarceration of a household member.

One of its most striking findings was the dose–response relationship: the more ACEs someone experienced, the higher their risk of mental health challenges, chronic illness and even premature death (Anda et al., 2006).

Research has highlighted that physically abused infants show higher levels of negative affect, while neglected infants display flattened affect (Gaensbauer & Hiatt, 1994).

If you would like to learn more about the way relationships shape wellbeing, you might find my article on attachment theory and anxious attachment helpful.

Beyond the original 10 ACEs

Since the first study, researchers have suggested expanding the ACEs framework. Contemporary research considers poverty, racism, bullying, community violence and even living in foster care as equally significant contributors to toxic stress (Finkelhor et al., 2013).

Moreover, based on the outcomes of a series of studies conducted in the early 2000s, it was discovered that ‘peer victimization,’ ‘peer isolation/rejection’ and ‘low socioeconomic status’ added ‘significantly to the prediction of physical health outcomes.’ Consequently, these contributors to toxic stress have been added to the ACEs framework.

Examples of adverse childhood experiences

abuse (physical, sexual, and emotional)
neglect (physical and emotional)
household dysfunction such as exposure to domestic violence, substance misuse, or mental illness in an adult
parental separation or divorce
household member being imprisoned
parental death or abandonment
bullying
homelessness

Prevalence of adverse childhood experiences

In England, around half of adults report at least one ACE, and 10% report four or more (Bellis et al., 2014). This shows how widespread and systemic adversity can be. And while those who report ACEs may not experience directly related symptoms, such as post-traumatic stress disorder, mounting evidence suggests that the effects can be expressed in seemingly unrelated health outcomes.

For example, in an NHS online article, ACEs are associated with:

A heightened likelihood of developing certain health conditions in adulthood, including cancer and heart disease, along with an increased vulnerability to mental health challenges, violence and victimisation.
A greater risk of experiencing mental health difficulties such as anxiety, depression and post-traumatic stress disorder (PTSD). Research indicates that one in three diagnosed mental health conditions in adulthood are directly linked to ACEs.
The longer an individual is exposed to an ACE, and the greater the number of ACEs experienced, the more significant the impact on their overall development and health.

Some additional areas that exposure to ACEs can affect include:

The ability to identify and regulate a range of emotions.
The capacity to form and maintain healthy friendships and relationships.
The ability to manage behaviour effectively within school environments.

Theoretical Perspectives of adverse childhood experience

Attachment theory

Attachment theory, first developed by John Bowlby (1969) and later developed by Mary Ainsworth (1978), helps explain how ACEs disrupt early relationships. Bowlby’s and Ainsworth’s research underscored the importance of healthy early attachment. They showed that when children form a ‘secure attachment’ with their primary caregiver, that child will likely form healthier relationships for the rest of their lives.

In addition, secure attached children are also more likely to enjoy a better quality of life.

In contrast, ‘insecure attachment’ result in the opposite outcomes: impaired ability to form healthy relationships through life, mistrust in people and a reduced quality of life. Bowlby and Ainsworth discovered that insecure attachment is often associated with childhood neglect or abuse.

You can learn more about relational patterns in this article avoidant attachment. For those who aspire to develop a grounded and comprehensive insight into attachment theory, start my course: Understanding Attachment.

Trauma and the neurobiological perspective

ACEs are now recognised as a form of developmental trauma. Research shows early adversity alters the stress-regulating HPA axis, making emotional regulation more difficult (Shonkoff et al., 2012; van der Kolk, 2014).

Sapolsky, who we briefly met in the introduction, observes that developmental trauma results in higher levels of circulating glucocorticoids (GCs) – colloquially referred to as stress hormones. In his books Behave and Determined, Sapolsky argues that persistent elevated basal levels of GCs may contribute to a plethora of long-term negative health outcomes.

Furthermore, Sapolsky notes that childhood stress can result in cytoarchitectonic changes in the threat response system of the brain, such as the enlargement of the amygdala. In addition to increasing a person’s susceptibility to mental health challenges, hyperalert threat response system predisposes a person to heightened states of anxiety and stress.

To make matters worse, elevated basal levels of GCs can result in the impaired growth of prefrontal cortex (PFC) – also known as the executive, or command centre of the brain. It’s widely understood that the PFC is instrumental in self-soothing and rationalising perceived threats. Thus, a person with a ‘normal’ PFC and a ‘normal’ amygdala will be more adept at managing stress-inducing situations and life challenges. The same, unfortunately, may not be true of the person who has been dealt a handful of ACEs.

Resilience and positive psychology

Up to now this article has been a dull and dismal read. One could be forgiven for inferring that the impact of ACEs is both negative and deterministic. If you stopped reading now, you would likely walk away with the assumption that those who suffer ACEs will wind up with a mental health disorder or some other health challenge. Thankfully, this is not the full story.

The uplifting news is that not all children with ACEs experience long-term harm. Resilience research (Rutter, 2012) and positive psychology (Seligman, 2011) highlight protective factors like supportive relationships and personal strengths. Moreover, counselling and coaching professionals can support children and adults to mitigate the impact of ACES by cultivating psychological flexibility while establishing a repertoire of coping strategies.

In addition, due to the widening understanding of the various causes and disparate impacts of ACEs, more interventions are being implemented to improve early detection. Furthermore, governments at both a national and regional level are mobilising resources to provide effective support networks for affected children.

The impact of Adverse Childhood Experiences

Psychological effects

ACEs are linked to anxiety, depression, PTSD and difficulties with intimacy and trust (Herman, 1992).

Physical health

Chronic stress responses from ACEs increase inflammation and the risk of heart disease, diabetes and autoimmune conditions (Danese & McEwen, 2012).

Social and occupational consequences

People with high ACE scores may face struggles in education, work, and relationships. At a societal level, ACEs contribute to cycles of inequality, crime, and homelessness (Bellis et al., 2014).

Assessment of ACEs

The ACE Questionnaire remains widely used, but it has limitations. Critics argue it oversimplifies experiences and ignores protective factors (McEwen & Gregerson, 2019). Professionals stress that ACE scores show risk, not destiny.

Trauma-informed practice

A trauma-informed approach prioritises safety, empowerment and choice in therapeutic relationships (SAMHSA, 2014).

Psychotherapy and counselling

Several therapies support people affected by ACEs:

Attachment-based therapies help repair relational wounds (Crittenden, 2008).
Cognitive behavioural therapy (CBT) targets unhelpful thought patterns (Beck, 2011).
Eye Movement Desensitisation and Reprocessing (EMDR) reduces trauma symptoms (Shapiro, 2017).
Somatic approaches address trauma in the body, such as somatic practices for anxiety (Ogden & Fisher, 2015).

Systemic and preventive approaches

The ACEs framework has also informed public health strategies. Parenting support, early education and trauma-informed schools reduce the impact of ACEs (Asmussen et al., 2020).

Building resilience after ACEs

Healing from ACEs is possible. Helpful interventions include:

Safe relationships with therapists, mentors, or peers.
Mind–body practices like mindfulness meditation, yoga and grounding exercises (van der Kolk, 2014).
Strengths-based coaching to build resilience and psychological flexibility (Seligman, 2011).

For a related discussion, see my article on complex trauma.

Conclusion

Adverse childhood experiences are a major public health challenge. They affect physical and psychological wellbeing, as well as exerting adverse social outcomes.

Yet ACEs are not destiny. With trauma-informed practice, therapy and resilience-building approaches, individuals and communities can break the cycle of adversity and foster healing.

References

Ainsworth, M. D. S. (1978). Patterns of Attachment. Hillsdale, NJ: Erlbaum.
Anda, R. F., Felitti, V. J., Bremner, J. D., et al. (2006). The enduring effects of abuse and related adverse experiences in childhood. European Archives of Psychiatry and Clinical Neuroscience, 256(3), 174–186.
Asmussen, K., Fischer, F., Drayton, E., & McBride, T. (2020). Adverse Childhood Experiences: What We Know, What We Don’t Know, and What Should Happen Next. Early Intervention Foundation.
Beck, J. S. (2011). Cognitive Behaviour Therapy: Basics and Beyond (2nd ed.). New York: Guilford.
Bellis, M. A., Lowey, H., Leckenby, N., et al. (2014). Adverse childhood experiences: Retrospective study to determine their impact on adult health behaviours and health outcomes in a UK population. Journal of Public Health, 36(1), 81–91.
Bowlby, J. (1969). Attachment and Loss: Vol. 1. Attachment. London: Hogarth Press.
Crittenden, P. (2008). Raising Parents: Attachment, Parenting and Child Safety. Cullompton: Willan.
Danese, A., & McEwen, B. S. (2012). Adverse childhood experiences, allostasis, allostatic load, and age-related disease. Physiology & Behavior, 106(1), 29–39.
Felitti, V. J., Anda, R. F., Nordenberg, D., et al. (1998). Relationship of childhood abuse and household dysfunction to many of the leading causes of death in adults. American Journal of Preventive Medicine, 14(4), 245–258.
Finkelhor, D., Shattuck, A., Turner, H., & Hamby, S. (2013). Improving the adverse childhood experiences study scale. JAMA Pediatrics, 167(1), 70–75.
Finkelhor D, Shattuck A, Turner H, Hamby S. A revised inventory of Adverse Childhood Experiences. Child Abuse Negl. 2015 Oct;48:13-21. doi: 10.1016/j.chiabu.2015.07.011. Epub 2015 Aug 7. PMID: 26259971.
Herman, J. L. (1992). Trauma and Recovery. New York: Basic Books.
McEwen, C. A., & Gregerson, S. F. (2019). A critical assessment of the ACEs framework in public health. Social Science & Medicine, 228, 48–60.
NHS Manchester University online article Adverse Childhood Experiences (ACEs) and Attachment: https://mft.nhs.uk/rmch/services/camhs/young-people/adverse-childhood-experiences-aces-and-attachment/ (cited: 30/10/2025).
Ogden, P., & Fisher, J. (2015). Sensorimotor Psychotherapy: Interventions for Trauma and Attachment. New York: Norton.
Public Health Wales (2015). Adverse Childhood Experiences and Their Impact on Health-Harming Behaviours in the Welsh Adult Population. Cardiff: Public Health Wales.
Rutter, M. (2012). Resilience as a dynamic concept. Development and Psychopathology, 24(2), 335–344.
SAMHSA (2014). Trauma-Informed Care in Behavioral Health Services. Rockville, MD: Substance Abuse and Mental Health Services Administration.
Seligman, M. E. P. (2011). Flourish. London: Nicholas Brealey.
Shapiro, F. (2017). Eye Movement Desensitisation and Reprocessing (EMDR) Therapy. New York: Guilford.
Shonkoff, J. P., Garner, A. S., et al. (2012). The lifelong effects of early childhood adversity and toxic stress. Pediatrics, 129(1), e232–e246.
Tedeschi, R. G., & Calhoun, L. G. (2004). Posttraumatic growth: Conceptual foundations and empirical evidence. Psychological Inquiry, 15(1), 1–18.
van der Kolk, B. (2014). The Body Keeps the Score. New York: Viking.

About Dr Laura Allen –

A Chartered Psychologist & Integrative Therapist, Dr. Allen specialises in a broad range of therapeutic methods. She is a published author of numerous research papers and Interactive Courses in the field of Psychology. Dr. Allen works one-to-one with clients and supervises other practitioners. She is also a proud member of the British Psychological Society assessment team supporting psychologists in training.