Childhood neglect may trigger permanent changes to the size and structure of a victim’s brain, research suggests.
Scientists from King's College London analysed the scans of 67 orphans who endured malnutrition and had little social contact.
They found the children’s brains were around 8.6% smaller than their nurtured counterparts when they reached adulthood.
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“We found structural differences between the two groups in three regions of the brain,” lead author Professor Mitul Mehta said.
“These regions are linked to functions such as organisation, motivation, integration of information and memory.”
Childhood depravation has previously been linked to mental-health issues, low IQ and a greater risk of attention deficit hyperactivity disorder (ADHD).
To better understand how it effects the brain, the scientists looked at data from the English and Romanian Adoptees study, which is made up of adopted children from the two countries.
The Romanian youngsters were subject to neglect before being taken in by loving families in the UK.
When aged 23-to-28, the victims underwent brain scans. These were compared against scans of 21 English adoptees of a similar age.
Results - published in journal Proceedings Of The National Academy of Sciences - show the longer the Romanian participants spent in orphanages, the smaller their total brain volume.
Each additional month in these institutions reduced the volume by 0.27%.
Compared to the English participants, the Romanians had “markedly smaller right inferior frontal regions of the brain both in terms of volume and surface area”.
In contrast, the Romanian’s right inferior temporal lobe was larger in volume, surface area and thickness, which is associated with fewer ADHD symptoms.
“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,” Professor Mehta said.
How neglect affects brain health is unclear.
The average adult human brain weighs between 1,300g (2lb 13oz) and 1,400g (3lb 1oz), and measures around 15cm (5.9 inches) long, according to Very Well Mind.
Men tend to have bigger brains than women, but are not necessarily more intelligent.
Sudden and disproportionate brain growth in babies has been linked to autism, suggesting rapid development prevents a child from making the connections that guide normal behaviour, How Stuff Works reported.