Childhood neglect produces smaller adult brains among Romanian orphans
Scientists have uncovered what they describe as the first “compelling evidence” of the effects of childhood neglect on brain development. The research tracks the long-term impacts among Romanian orphans who spent time in the country’s severely depriving institutions, with scans demonstrating a marked difference in brain size compared to a group of English adoptees.
The results are the latest to emerge from a three-decade research project observing the long-term effects of Romania’s orphanages under the communist regime, which fell in 1989.
The tens of thousands of children living in these institutions endured poor hygiene and malnourishment, and little social contact, personalized care and cognitive stimulation. Those participating in the research project, known as the "The English and Romanian Adoptees (ERA) study," were later adopted by nurturing families in the UK.
Scientists working on the project have previously teased out some useful insights, including a reduced amount of white matter in the brain among the Romanian orphans as teenagers, and a range of mental health problems as early adults.
For the latest study, neuroscientists at Kings College London analyzed MRI brain scans of 67 young adults who spent between three and 41 months in Romanian orphanages before adoption into UK families. The brain scans of these subjects, aged 23 to 28 years old, were then compared to MRI brain scans of 21 English adoptees aged 23 to 26, who had not endured early childhood deprivation.
The most striking finding was that the brains of the Romanian adoptees were around 8.6 percent smaller than the English adoptees. The team also says that longer periods of deprivation correlated with smaller and smaller volume, calculating that each additional month spent in the institutions was associated with a 0.27-percent reduction in total brain size.
These volume changes brought on by childhood deprivation were associated with lower IQ and more symptoms of ADHD (attention deficit hyperactivity disorder). The team zeroed in on three brain areas in particular that exhibited differences in volume – the right inferior frontal region, the right inferior temporal cortex and the right medial prefrontal cortex.
“These regions are linked to functions such as organization, motivation, integration of information and memory,” says neuroimaging lead for the study, Professor Mitul Mehta. “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.”
The scientists considered the possibility that other factors could have contributed to these differences in brain size, including nutrition, physical growth and a genetic predisposition to smaller brains, but ruled them out following investigations.
"The English and Romanian Adoptees study addresses one of the most fundamental questions in developmental psychology and psychiatry – how does early experience shape individual development?” says principle investigator, Professor Edmund Sonuga-Barke. “It’s essential to recognize 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.”
The research was published in the journal Proceedings of the National Academy of Sciences.
Source: Kings College London