What if there are some children who need extra help, though, to boost them up to the same level of development as their more resilient peers? We still know very little about the mechanisms involved in resilience and how we can help them to be more effective. If we think of it as an adaptive process, how do our brains, our thought processes and our behaviours change to help us to cope with adverse early circumstances? Eamon McCrory, Professor of Developmental Neuroscience and Psychopathology at University College London, is investigating just this.

McCrory and his team are collecting a combination of brain images, cognitive assessments, DNA and perceptual data, from children who have been maltreated and allocated a social worker, and also from a control group who have not. The two groups have been painstakingly matched by age, pubertal development, IQ, socioeconomic status, ethnicity and sex. The researchers aim to follow their cohort for as long as funding allows, trying to unpick what would predict which of the children who have been maltreated will go on to develop difficulties and which will be resilient.

McCrory used to work clinically for the National Society for the Prevention of Cruelty to Children and he understands the clinical challenges that are involved with this population: “Resources are very limited,” he explains, “so if you have a hundred children referred to social services who experienced maltreatment, we know that the majority of them actually won’t develop a mental health problem. But then a minority are at significantly elevated risk… At the moment, we have no reliable way of knowing which kid is which. So it seems sensible to try and move the focus back from the disorder to a much earlier stage in the process and characterise the risk profile… Only longitudinal designs can give us this information.”

McCrory’s research is searching for reliable clues that a child will go on to develop difficulties, so that we can begin to know who to target to help. So far, McCrory has identified three main areas where there are likely to be differences: threat processing, brain structure, and autobiographical memory.

Studies of war veterans as well as maltreated children reveal that areas of the brain involved in processing threats, such as the amygdala, are more responsive both in the soldiers coming back from war and in children who have experienced early abuse. It makes sense that if you have been in danger a lot, then your brain may have adapted to be very sensitive to threat. “Our main theoretical proposal at the moment is around a concept of latent vulnerability,” McCrory says, “which is the idea that maltreatment… leads a number of biological and neurocognitive systems to adapt to a context characterised by early stress, threat and unpredictability, and adaptations to those systems may be adaptive and helpful in that context, but embed vulnerability in the longer term.”

The team are also scanning the children’s brains to try to see whether difference in brain structure in maltreated children are stable over time or changeable. “We know very little about malleability of brain structure over time,” explains McCrory. “We know there are structural differences in the orbitofrontal cortex and the mediotemporal lobe, for example, which are quite robust, but we’ve no idea whether they are static or whether they may shift over time, at least in certain children.”

The third area the team think is important is autobiographical memory. The brain system involved in thinking about and processing memories of personal history might also be shaped by early traumatic experiences in a way that is adaptive in the short term but unhelpful in the longer term.

“Autobiographical memory is the process whereby you record and encode your own experiences and make sense of [them],” explains McCrory. “We know that individuals who have depression and PTSD [post-traumatic stress disorder] have… an over-general autobiographical memory pattern, where they lack specificity in their recall of past experience… We also know that kids who have experienced maltreatment can show higher levels of this over-general memory pattern. And longitudinal studies have shown that a pattern of over-general memory can act as a risk factor for future disorder.

“One hypothesis is that the over-general memory limits an individual’s ability to effectively assimilate and negotiate future experiences, because we draw on our past experiences to be able to predict the contingencies and likelihood of events in the future, and use that knowledge to negotiate those experiences well. So… over-general memory might limit one’s ability to negotiate future stressors.”

It makes sense that if horrible things have happened to you in the past, you will want to avoid thinking about and remembering them, which might lead to a tendency to have a memory that’s light on detail. McCrory’s team are finding reliable associations between over-general memory patterns and childhood maltreatment.

Back to Mirena in Hawaii, and she finds it hard to know whether her memory has been affected by her early experiences: “from a personal perspective I wouldn’t know,” she says. “We don’t know what we don’t remember.” The memories she does have of her family growing up are mixed. In our conversations, she often describes them fondly: her father as “a brilliant man” who “read all the time” and was “just kind of ordinary except when he was drunk”, and her mother as “a beautiful Hawaiian woman who had a beautiful voice, who did her best”. Alongside these descriptions are darker memories, of coming home to arguments in the kitchen, or worse: “I saw my mother try to kill my father on several occasions, cos daddy was drunk and mom was mad. And I was usually the one that would try to stop them.” While we talk, Mirena sometimes becomes tearful, remembering difficult times, and other times speaks with passion about the importance of protecting other children.