Childhood trauma and adverse childhood experiences (ACEs)

Childhood trauma means frightening, harmful or neglectful experiences in the years when the brain and body are still developing. Researchers call them adverse childhood experiencesAdverse childhood experiencesPotentially traumatic events in the first 18 years of life, such as abuse, neglect or violence at home. They raise the risk of later health problems, but they do not decide a child's future.Read the full definition, or ACEs. On average, people who had more of them have more health problems as adults — both mental and physical. But averages are not destinies. Many people with difficult childhoods live healthy lives, and the single most powerful protection is a safe, caring relationship.

This page explains what the research actually found, what an 'ACE score' can and cannot tell you, why hitting children is no longer considered harmless, and what helps — for children now, and for adults carrying their childhood with them.

What the original ACE study found

The ACE study was a collaboration between the US Centers for Disease Control and Prevention and Kaiser Permanente, a large health organisation in California. In the 1990s, questionnaires were sent to 13,494 adults who had had a routine medical check-up; 9,508 replied. They were asked about seven kinds of childhood experience: psychological, physical or sexual abuse; violence against their mother; and living with someone who misused alcohol or drugs, was mentally ill or suicidal, or had been imprisoned. Later versions added neglect and parental separation.

What an ACE score does and does not mean

An ACE score is simply the number of categories a person ticks. It became famous, and online 'ACE tests' followed. In 2020, one of the original investigators co-wrote a paper warning that the score was designed for research on populations, not for screening or diagnosing individuals. It does not measure how severe something was, how long it lasted, how old you were, or whether someone kind was there to help — all of which matter enormously.

How early adversity can affect health

Harvard's Center on the Developing Child describes toxic stress: strong, frequent or prolonged activation of the body's stress systems without a supportive adult to buffer it. Short bursts of stress, handled with a caring adult's help, are a normal part of growing up. Toxic stress is different, and children exposed to it are at greater risk of heart disease, diabetes and depression later in life. Several pathways are involved:

• Stress biology — a stress system tuned to expect danger, with changes in cortisolCortisolA steroid hormone made by the adrenal glands that helps the body respond to stress and regulates blood sugar, metabolism and inflammation. Levels peak in the morning and fall at night.Read the full definition and inflammationInflammationInflammation is the body's response to injury or infection: blood flow increases, fluid and immune cells arrive, and the area becomes red, warm, swollen and painful. It is a repair process, and it becomes a problem only when it persists.Read the full definition
• Coping behaviours — smoking, overeating, alcohol or drugs often start as ways to manage feelings, and then cause their own harm
• Mental health — higher rates of depressionDepressionA medical condition in which low mood or loss of interest lasts most of the day, nearly every day, for at least two weeks, and affects sleep, energy and daily life.Read the full definition, anxiety, PTSDPost-traumatic stress disorderA condition that can follow a frightening or life-threatening event, in which the memory keeps intruding, reminders are avoided and the person stays constantly on guard.Read the full definition and complex PTSDComplex PTSDA form of PTSD that follows long-lasting or repeated trauma that was hard to escape, such as childhood abuse or ongoing domestic violence. It adds lasting problems with emotions, self-worth and relationships.Read the full definition
• Relationships and trust — difficulty trusting others, including doctors, which can make managing a long-term condition such as diabetes harder

Childhood adversity in Pakistan

Pakistani research is limited, but it points to high exposure. A 2025 study of 454 college students aged 18 to 25 in Rawalpindi found that 98% reported at least one ACE and 82% reported three or more. The commonest were witnessing violence in the community (88%), among peers (83%) and at home (73%); 60% reported emotional abuse and 47% physical abuse. Students with six or more ACEs had over three times the odds of poor mental wellbeing. It was a convenience sample, not a national survey, but it matches what many clinicians hear.

Some of this is bound up with ideas about discipline that many of us grew up with: that a child who is beaten will turn out straight, that shouting and shaming are how respect is taught. Parents who believe this usually love their children and are doing what was done to them. The evidence now says there is a better way.

Hitting children: what the evidence says

WHO estimates that around 1.2 billion children are physically punished at home each year. Its 2026 fact sheet is clear: the evidence shows corporal punishment harms children's physical and mental health, increases behaviour problems over time, and has no positive outcomes. Even light smacking carries a built-in risk of escalating, and parents who use it are at higher risk of going on to severe maltreatment. Punishments that humiliate, threaten or ridicule a child often travel alongside it and cause similar harm.

This is not a judgement of any faith or culture. It is the same finding across countries and cultures, and it is why WHO supports parenting programmes that teach non-violent discipline.

What protects children

A 2019 study of over 6,000 adults measured positive childhood experiences — being able to talk to family about feelings, feeling that family stood by you in hard times, enjoying community traditions, belonging at school, feeling supported by friends, having at least two non-parent adults who genuinely cared, and feeling safe at home. Adults who recalled six or seven of these had 72% lower odds of depression or poor mental health than those who recalled two or fewer, and the benefit held whatever their number of ACEs.

In a Pakistani family, that caring adult may be a grandmother, a chacha or khala, a teacher, or an imam. Joint-family life can be a source of stress, but it also means more adults who can notice a child and stand by them. Harvard's Center on the Developing Child notes that safe, stable environments and responsive relationships can prevent or even reverse the damaging effects of toxic stress — the basis of resilienceResilienceThe ability to adapt and recover after hardship, loss or stress. It is not a fixed trait you either have or lack; it grows from relationships, habits and support.Read the full definition.

Parenting to break the cycle

1. Notice and praise the behaviour you want, specifically and often — it works better than punishing what you do not want.
2. Keep routines predictable: meals, sleep, homework, prayer. Children feel safer when they know what comes next.
3. Use calm consequences — losing screen time, a short time-out, fixing what was broken — instead of hitting or humiliation.
4. Repair after you lose your temper: 'I shouted, that was wrong, I am sorry.' This teaches more than never making mistakes.
5. Look after yourself. A parent's untreated depression, anger or exhaustion is one of the biggest risks to a child, and getting help for it is an act of care for the child.
6. Protect children from violence between adults in the home; witnessing it harms them even when they are not hit.

What helps adults

Adults who had difficult childhoods do not need to relive every memory to feel better. What helps depends on what you are struggling with now:

• If you have flashbacks, nightmares or constant fear, trauma-focused therapy such as trauma-focused CBTCognitive behavioural therapyA structured, time-limited talking therapy that helps you notice and change the thoughts and behaviours that keep a problem going. It is a first-line treatment for depression and most anxiety problems.Read the full definition or EMDREMDREye movement desensitisation and reprocessing: a structured trauma therapy in which you recall distressing memories while doing side-to-side eye movements, so the memories become less intense.Read the full definition is effective, even decades later.
• If low mood, anxiety or anger are the problem, talking therapy and, where appropriate, medication help regardless of their roots.
• Understanding that what happened was not your fault — children are never responsible for how adults treat them — is often a turning point.
• Building one or two trusting relationships, and learning to calm the body when it goes into alarm, helps rewire patterns set early in life.
• Look after your physical health: have your blood pressure, blood sugar and weight checked, and tell your doctor if smoking, eating or drinking are how you cope.

When to get help

• Memories from childhood keep intruding, or you have nightmares and feel constantly on guard
• You are harming yourself, or using alcohol, drugs or tablets to numb feelings
• You find yourself hitting or screaming at your own children and cannot stop
• Relationships repeatedly break down because trust feels impossible
• A child is being abused or neglected now

If a child tells you about abuse

1. Stay calm and listen. Your reaction decides whether they ever tell anyone again.
2. Tell them you believe them and that it is not their fault.
3. Do not promise to keep it secret — explain that you need to get help to keep them safe.
4. Do not confront the person accused in front of the child.
5. Get help the same day: 1121, 15, or a doctor you trust. Family honour must never outweigh a child's safety.