Oxytocin is a natural hormone involved in bonding behavior, such as the attachment a new mother feels toward a baby, that some researchers are testing in children with social deficits such as autism spectrum disorders.
But a study in an animal model of bonding behavior found giving it long term could have the opposite effect.
Dr. Karen L. Bales, the vice chairwoman of psychology at the University of California-Davis, has been studying human bonding behavior and the science behind it using close animal models, such as prairie voles, which are monogamous.
Studies have found that at some doses oxytocin increases trust and social behavior, such as recognition of emotions, among those with autism.
Some clinical trials are testing it in those with autism, but it took Bales only an hour to call around and find three providers who were giving it to patients off-label to help treat social disorders.
“So it is out there, and it’s an engaging idea because it certainly is involved in social bonding,” said Bales, a former Augusta resident who attended St. Mary on the Hill Catholic School and Aquinas High School. “And there are all of these human studies now that show that if you just give one dose it increases trust and emotion recognition and all of this good stuff. But the bad part is that until now we didn’t have any long-term studies to see if the chronic effects are the same as the short-term effects.”
She treated prairie voles with chronic doses of oxytocin over essentially the adolescent period of their development, the same age the human trials are targeting.
Instead of the normal bonding behavior, the male voles in particular reduced the amount of time they spent seeking partners and did not pair up with females as much as they would normally.
It is particularly troubling that males would be adversely affected because human social attachment disorders tend to be more heavily male, Bales said. It should also sound a note of caution because of the time period involved, she said.
“We just always have to be really careful about what we’re doing with a developing brain,” Bales said.
She still needs to study the brains to find out exactly what changes might have occurred biologically, but it could involve a similar hormone called vasopressin.
It is very closely related chemically to oxytocin, and the two hormones can activate cell receptors for the other, but not always with the same effect, Bales said.
“Vasopressin, sometimes it has similar effects to oxytocin; sometimes it has quite diametrically opposed effects,” she said. “It can, for instance, increase aggression.”
The problem might also be the dosing. In human studies, different doses of oxytocin in schizophrenics had opposite effects on increasing or decreasing recognition of emotion.
Emory University researchers are testing a drug that helps elicit natural oxytocin production, which might prove to be a better approach, Bales said.
Though her research could give parents pause about using oxytocin on autism patients, Bales said she could understand why they were willing to try it.
“Parents are desperate for something that will help their child,” she said. “But you don’t want to make it worse.”