Bonding, brain chemistry linked
Children adopted from abroad often have difficulties adjusting to their new families and to life in this country, exhibiting poor social skills, problems bonding with new family members and reticence in dealing with strangers.
Those difficulties are generally traced back to emotional deprivation in large orphanages, where infants often outnumber staff by 40 to 1, and caregivers do little more than feed and change the infants.
Now Wisconsin researchers have found that such deprivation can produce relatively permanent changes in a child’s brain chemistry, impairing production of hormones, such as oxytocin, that are crucial to bonding and social interaction.
“This work makes a link between complex emotional behaviors and the developing brain,” said lead author Seth D. Pollak, a psychologist at the University of Wisconsin.
But, he said, “It’s extremely important that people don’t think that this work implies that these children are somehow permanently delayed.” Pollak and his colleagues reported their findings last week in the Proceedings of the National Academy of Sciences.
Many children adopted from abroad grow up to be perfectly normal, he noted.
“All we are saying is that in the case of some social problems, here is a window into understanding the biological basis ... and how we might design treatments,” Pollak said.
Oxytocin, sometimes known as “the peptide of love,” plays a crucial role in many social situations. Studies in animals have shown that increased levels are stimulated by pleasing sensory experiences, such as comforting touches and smells. As levels rise, animals -- and presumably humans -- form social bonds, display parent-child attachments and form memories of the experiences.
Another recent study in humans showed that spraying oxytocin into the nose can increase trust among strangers.
Children raised in orphanages where they don’t receive contact with adults beyond the bare necessities aren’t able to produce the hormone in such situations, interfering with their ability to develop normally, Pollak said.
The findings are important because about 200,000 children adopted abroad are now living in the United States and an additional 20,000 are brought in each year, a third of them from Eastern Europe.
A key to the studies was a technique developed by University of Wisconsin endocrinologist Toni Ziegler to measure levels of oxytocin and vasopressin in urine and correlate them to levels in the brain.
For the new study, researchers led by doctoral student Alison Wismer Fries in Pollak’s lab studied 18 children who had spent, on average, the first 18 months of their lives in orphanages in Romania and Russia before being adopted into upper- middle-class U.S. families. They compared them with 21 children born into similar families.
Their primary tool was a 30-minute video game that promoted interaction between the child and the mother or another adult woman. With the child sitting on the adult’s lap, the computer would give commands to promote interactions, such as whispering or tickling each other or patting heads.
The researchers measured hormone levels before and after the session. The children who had not been adopted showed a distinct increase in oxytocin levels while playing with their mothers, but not while playing with the strangers. The adopted children did not show an increase in either case, indicating that they did not respond normally to a bonding experience -- even though they had been with their U.S. families for an average of nearly three years.
The adopted children had significantly lower overall levels of vasopressin, but the levels did not change in either group when they played the game.
Pollak said the research eventually could lead to treatments for such children. “Given what some [adopted] children struggle with, wouldn’t it be great if there was a medicine that could make them feel safe?”
