TUESDAY, June 20 (HealthDay News) -- A nasal spray containing a "love hormone" may actually help defuse marital squabbles, scientists reported Tuesday.

The hormone, oxytocin, which has been linked with the ability to maintain healthy interpersonal relationships and healthy psychological boundaries with other people, appears to cut stress during tense social situations or conflict, the researchers told a news conference.

To determine that, the researchers used a nasal spray of oxytocin on couples who were put in a stressful situation. They found that levels of cortisol -- a hormone normally elevated in stressful situations -- could be significantly reduced in those given oxytocin.

The findings were presented Tuesday at the International Congress of Neuroendocrinology, in Pittsburgh.

"We were wondering which hormone or neural transmitter would mediate the positive effect of social bonding," said lead researcher Beate Ditzen, a postdoctoral fellow in the department of psychiatry and behavioral sciences at Emory University, in Atlanta. "This led us to research on oxytocin."

In their study, Ditzen and colleagues from the University of Fribourg and the University of Zurich, both in Switzerland, had 50 couples engage in mock arguments about unresolved situations in their relationship.

Before the couples began arguing, half were given a nasal spray containing oxytocin, while the other couples were given a placebo. Using saliva samples, Ditzen's team monitored levels of the so-called stress hormone cortisol. The couples also completed questionnaires that evaluated the quality and social support of their relationships.

"Preliminary analysis indicates that there was no increase in cortisol increase in either group," Ditzen said. "But we had a significant cortisol decrease in the oxytocin group. This decrease was significantly different from the placebo group."

In addition, couples who received oxytocin were able to express their emotions, both negative and positive, more openly than those who received a placebo, Ditzen said. "From a psychological standpoint, this is what we are trying to do in resolving conflicts," Ditzen added.

These finding suggest that oxytocin has a positive effect, Ditzen said, but noted, "We have to be cautious, and wait until all the data is analyzed before we can draw a final conclusion."

Oxytocin, which is produced in the brain and released by the pituitary gland, has been linked in prior research to the ability of people to trust others and take care of each other. A joint Japanese-American study last fall found that female mice bred without the hormone forgot to take care of their young.

One expert thinks oxytocin may be useful in treating some psychiatric problems.

"This is quite interesting and suggests a potentially important role for oxytocin in social interactions," said Elliott Albers, director of the Center for Behavioral Neuroscience at Georgia State University. "There is vast animal data that suggests that oxytocin may be linked to pair bonding."

Oxytocin "may be useful for autism," he added. "It could be useful in treating some disorders, but we will have to see what kind of disorders it might be effective in,"

Another study presented at the meeting suggests that hormones such as testosterone and cortisol may contribute to the "home-field advantage" in sports. The need to defend one's territory and perform well in front of hometown fans may account for that advantage, researchers report.

In this study, Justin Carre, a doctoral candidate in the department of psychology at Brock University in Ontario, Canada, and colleagues monitored testosterone and cortisol levels in members of a Canadian ice hockey team. Hormone levels were checked before and after games.

The researchers found that when the home team won, testosterone levels were higher both before and after the game. Moreover, testosterone levels were particularly high before a home game, the researchers noted. This suggests the hormone surge may relate to defending one's territory, the scientists said.

In addition, the "increase [in cortisol levels] after the loss was significantly greater after the loss than after the win," Carre said. "One can speculate that loss of status is more stressful."

Levels of cortisol were also higher when playing at home. This may mean that playing in front of family and friends increased stress not felt on the road. However, pre-game self-confidence was also higher when the team played at home. And there was a strong correlation between pre-game self-confidence and performance, Carre's team found.

More information

For more on the impact of stress on health, visit the National Mental Health Association.