How adverse experiences and trauma during childhood affect the brain

Homelessness one of most pressing issues in relation to childhood trauma, seminar hears

While brain health is often something associated with later life, trauma, neglect and adverse childhood experiences can have a significant impact on our lives. "Our beginning in life is very influential for our ends," Trevor Spratt, professor in childhood research and co-director of the Trinity Research in Childhood Centre, said during the Brain Health and Housing: Understanding the Past – Trauma and Adverse Childhood Experience seminar – a joint initiative from the Global Brain Health Institute and Respond.

The more adverse childhood experiences a person has had, the greater the impact on their adult life, Prof Spratt explained. This is evident even when it comes to physical health with an increased likelihood to develop diseases such as type 2 diabetes, respiratory disease and heart disease, along with a significantly reduced life expectancy. “If you’ve had a good childhood you will probably have good mental health through your life, but with each adversity of experience the odds of having poor mental health outcomes increase.

“Adverse experiences result in a neural development disruption. It starts to express itself in social, emotional and cognitive impairment – often picked up by school teachers. Then, by the time adolescence appears, you’ve got people involved in high-risk behaviours, smoking, drinking early – staying with it, taking drugs – not coming off and staying with those. The translation then in middle age and adulthood – disease, disability and social problems become expressed in that way. And then longevity of life is compromised.”

Adverse childhood experiences can also increase the risk of dementia, Prof Spratt explained. “What causes the damage really are problematic human relationships which damage the psyche of the individual growing up. But the healing is also in human relationships.”

Emergency accommodation

Homelessness is one of the "most pressing issues in relation to childhood trauma", Dr Niall Muldoon, Ombudsman for Children, told the seminar, recalling the findings of a report published by his office in 2019 which had highlighted the "negative impacts that living in family hubs had, including the lack of privacy, the struggle to get sleep, the difficulty to study, the lack of opportunity to play, and problems maintaining relationships with family and friends".

“Parents talked to us about children under two years of age having lack of space to crawl and being developmentally cramped because of it; the fear that children would have of loud voices and noises and violence that may occur at times within the settings of emergency accommodation.”

For teenagers, homelessness presented different difficulties: “The teenager trying to find a way, trying to be independent, is losing her opportunity to bond deeper with her friends and having to lie and suffer the stigma of homelessness.

“Homelessness results in multiple disruptions to family life and is rarely the manifestation of only one crisis for that family, but the accumulation of a series of crises,” Dr Muldoon continued. “The loss of a home and friends, unemployment, the disruption of education, poor physical and mental health, ultimately leads to the loss of the sense of safety and security that a home provides.”

In a post-pandemic world, Dr Muldoon said that Ireland should not return to the normal of old but seek a new normal for children that would look to eradicate child poverty and homelessness by 2026. These aims are set out in an initiative called "A Better Normal" which, Dr Muldoon explained, calls on all political parties to make sure these objectives are achieved. "It's doable and we can make it happen with the right level of commitment from Government.

“I’m not sure that the policies that have been pursued by various governments since the start of the economic crash have really had our citizens’, particularly our children’s, needs to the fore.

“Psychological studies have shown . . . that traumatic experiences in childhood have the potential to alter a child’s brain through the narrowing of neural pathways which may cause longer-term effects in areas such as attachment issues, physical health, emotional regulation, dissociation cognitive abilities, self-concept and behavioural control. Brain development in infancy and early childhood lays the foundation for all future development.”

Dr Muldoon said he’s been “pushing for therapeutic support and services to be available in all schools . . . from primary through to secondary so that we can reach it [trauma] early”.


Dr Cathal McCrory, associate professor of life course development and ageing, Trinity College, explained that "individuals growing up in more disadvantaged social backgrounds will get diseases earlier and they'll die earlier on average, compared to their more advantaged counterparts. They'll also live a larger proportion of their shorter lives living with illness and disability.

“Using data from the Growing Up in Ireland study, we’ve established that there’s a social gradient in obesity in very early life. Already by three years of age children whose parents have a primary level education are twice as likely to be obese compared with children of parents who have a third-level education.

“Essentially socio-economic disadvantage in life, or an adverse childhood exposure like physical abuse or sexual abuse, triggers or precipitates a whole chain of risk.”

The Irish Longitudal Study on Ageing has shown that “persistent poverty is more injurious to your health than transient poverty”, Dr McCrory continued. “Recent figures from the ERSI suggests that 16.6 per cent of children here in Ireland are growing up at risk of poverty”, which, Dr McCrory explained, “means their income and their resources are so inadequate it precludes them from having a standard of living which is acceptable by our society, resulting in isolation and social exclusion”.

The impact on the brain of adverse childhood experiences include “earlier pubertal maturation” and “more rapid development in areas of the brain that are associated with independence, emotional regulation in early life”, and it’s also associated with “age acceleration”, he continues, explaining that evolution suggests earlier development may be a response to a threatening environment. The trade-off for earlier maturation, however, is “essentially poor health on a shorter life span in later life”. “We found in the study that individuals who experienced poverty were two years biologically older when assessed at 50 years of age and older – and they’re also aging at a faster rate.”

‘Terrible year’

Dr McCrory said we “too often hear the refrain ‘children are resilient’. Generally it’s used to justify government or societal inaction on particular things. How else can it be acceptable that almost one in five children growing up in Ireland today are at risk of poverty in what is one of the wealthiest countries in the EU - unless we think, ‘it’s okay, children are resilient and we can always fix it at a later date’.

“2021 was a terrible year for children . . . you had schools and creches closed. You had children considered vectors for transmission – allowing some people to discriminate effectively against them. You had the normal rites of passage of childhood – peer group interaction, going to the playground, sports and activities all closed down for children . . . Essentially the rights of childhood were denied. We’ve heard a lot of focus recently about the economic recovery, but it seems to me we’ve been rather less focused on addressing the impacts of the pandemic on children who were disproportionately impacted. People tend to use the term ‘resilience’ like it’s an individual characteristic of the person, and this ignores the fact that resilience is something that actually needs to be fostered and developed at the societal level.

“What better way to build resilience than by, number one, eliminating childhood poverty and, secondly, by investing in early childhood programmes that mean every child gets a good start in life.”