Do early interactions shape smarts?

Deprivation experienced during childhood may affect brain size, which may be associated with lower IQ and attention-deficit hyperactivity disorder. (For Spectrum Health Beat)

Severe deprivation in childhood can lead to a smaller-than-normal brain, lower IQ and attention deficits in early adulthood, a new study suggests.

Researchers analyzed MRI brain scans of 67 young adults, ages 23 to 28, who were institutionalized as children in Romania during the Communist regime.

They had spent between 3 and 41 months in institutions, where they were often malnourished and had little social contact or stimulation.

All were later adopted by families in the U.K.

Their brain scans were compared to those of 21 English adoptees, ages 23 to 26, who didn’t experience institutional deprivation during childhood.

The brains of young adult Romanian adoptees were 8.6% smaller than the brains of English adoptees.

The more time that the Romanian adoptees spent in the institutions, the smaller their brain. Each additional month of deprivation was associated with a 0.27% decrease in total brain volume, the scans revealed.

The deprivation-related brain changes were associated with lower IQ and more symptoms of attention-deficit hyperactivity disorder.

The study—recently published in the Proceedings of the National Academy of Sciences—is the first to examine how severe deprivation in childhood affects a young adult’s brain structure.

“Previous research on the English and Romanian Adoptees 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,” said first study author Nuria Mackes.

“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,” Mackes said.

She’s a postdoctoral researcher in the Institute of Psychiatry, Psychology and Neuroscience at King’s College London.

Principal investigator Edmund Sonuga-Barke, a professor at IoPPN, said the study addresses one of the most basic questions in developmental psychology: How does early experience shape individual development?

“It’s essential to recognize that these young people have nearly always received great care in loving adoptive families since they left the institutions,” he said in a college news release. “However, despite a lot of positive experiences and achievements there remain some deep-seated effects of deprivation on these young adults.”

from Spectrum Health Beat https://ift.tt/31aC3LM