According to the research, the longer the time the Romanian adoptees spent in the institutions, the smaller the total brain volume, with each additional month of deprivation associated with a 0.27% reduction in total brain volume. Deprivation related changes in brain volume were associated with lower IQ and more symptoms of attention deficit hyperactivity disorder (ADHD). Published in Proceedings of the National Academy of Sciences (PNAS), the study analysed the MRI brain scans of 67 young adults, aged 23-28 years, who were exposed to severely depriving conditions in Romanian institutions under the Communist regime and subsequently adopted into nurturing families in the UK. They were compared to the MRI brain scans of 21 English adoptees aged 23-26 years who had not suffered this institutional deprivation. MRI scans were conducted at the Centre for Neuroimaging Sciences at King’s College London, as part of the Medical Research Council (MRC) funded English and Romanian Adoptees Brain Imaging Study (ERABIS). This is part of the larger ERA project that has collected information from Romanian and English adoptees over time including measures of mental health and cognitive performance.

The English and Romanian Adoptees (ERA) study addresses one of the most fundamental questions in developmental psychology and psychiatry – how does early experience shape individual development? – Principal investigator, Professor Edmund Sonuga-Barke from the Institute of Psychiatry, Psychology & Neuroscience

Statistical analysis showed that, in this group of young Romanian adults, those changes in brain volume that were related to deprivation were also associated with lower IQ and more ADHD symptoms. This implies that changes in brain structure could play a mediating role between the experience of deprivation and levels of cognitive performance and mental health. The research investigated other possible factors that could have influenced the results but found the results were unaffected by level of nutrition, physical growth and genetic predisposition for smaller brains. The principal investigator of the study, Professor Edmund Sonuga-Barke from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King’s College London said: ‘The English and Romanian Adoptees (ERA) study addresses one of the most fundamental questions in developmental psychology and psychiatry – how does early experience shape individual development? It’s essential to recognise that these young people have nearly always received great care in loving adoptive families since they left the institutions. However, despite a lot of positive experiences and achievements there remain some deep-seated effects of deprivation on these young adults.’

Showing these very profound effects of early deprivation on brain size and then showing that this difference is associated with low IQ and greater ADHD symptoms provides some of the most compelling evidence of the neuro-biological basis of these problems following deprivation – First author, Dr Nuria Mackes from the Institute of Psychiatry, Psychology & Neuroscience

First author, Dr Nuria Mackes from the IoPPN said: ‘Previous research on the English and Romanian Adoptees (ERA) study has suggested that the emergence and persistence of low IQ and a high level of ADHD symptoms involves structural changes in the brain but, until now, we have not been able to provide direct evidence of this. Showing these very profound effects of early deprivation on brain size and then showing that this difference is associated with low IQ and greater ADHD symptoms provides some of the most compelling evidence of the neuro-biological basis of these problems following deprivation.’ The study also investigated where these changes were occurring in the brain and what localised features contributed to the differences. In comparison to the UK adoptees, the young Romanian adults who had suffered deprivation as children had markedly smaller right inferior frontal regions of the brain both in terms of volume and surface area. In contrast the right inferior temporal lobe was larger in volume and surface area and thickness for the Romanian young adults and this was associated with lower levels of ADHD symptoms. This implies that this increase in volume and surface area in this region may play a compensatory role in preventing development of ADHD symptoms. In the right medial prefrontal region, the longer the duration of deprivation, the larger the volume and surface area.

Local differences in adult brain structure associated with early deprivation

The neuroimaging lead for the study, Professor Mitul Mehta from the IoPPN said: ‘We found structural differences between the two groups in three regions of the brain. These regions are linked to functions such as organisation, motivation, integration of information and memory. It’s interesting to see the right inferior temporal lobe is in fact larger in the Romanian young adults and that this was related to fewer ADHD symptoms, suggesting that the brain can adapt to reduce the negative effects of deprivation. This may explain why some individuals appear less affected than others by deprivation. We believe this is the first time that research has shown such compelling evidence of compensatory effects around deprivation.’

It’s interesting to see the right inferior temporal lobe is in fact larger in the Romanian young adults and that this was related to fewer ADHD symptoms, suggesting that the brain can adapt to reduce the negative effects of deprivation. This may explain why some individuals appear less affected than others by deprivation – Neuroimaging lead for the study, Professor Mitul Mehta from the Institute of Psychiatry, Psychology & Neuroscience