A new study has found that oxytocin improves peoples' ability to evaluate character. Researchers say that the discovery might pave the way for new treatments of mental disorders and addictions.

Oxytocin is also called as a bliss hormone. Animal studies have shown that this hormone plays an important role in keeping mating pairs together. This hormone helps establish lasting relationships and reduces fear.

For the study, Dr. Siri Leknes, a research fellow at the Department of Psychology at the University of Oslo, administered nasal sprays to 40 healthy students. One set of students received nasal spray that had salt-water while the other received oxytocin.

They were then showed pictures of angry, happy and sad expressions. There were some pictures among them that had "hidden expressions" which required attention from the subconscious mind.

Leknes found that when people who were given oxytocin saw these pictures, they saw more intense expressions in them than the control group. The oxytocin-group saw angry faces as angrier and happy faces as happier.

“We found that oxytocin intensified test subjects’ awareness of the emotions present in the photos. Faces expressing anger stood out as angrier and less happy, and correspondingly, faces expressing happiness were happier,” said Leknes.

All participants were tested twice without them knowing if they were receiving salt-water or oxytocin nasal spray to ensure that there is no bias in the study.

“It turns out that those with the lowest aptitude for judging emotional expression properly – that is, those with the poorest scores during the saltwater round – were the ones who showed the greatest improvement using oxytocin. This is really fascinating; the people who need it the most are thus the ones who get the most out of using the hormone,” Leknes said in a statement.

In many mental disorders and addictions, people lose the sense of judging other peoples' emotions. Leknes says that oxytocin could be used as a supplementary treatment for people who lack the ability to distinguish emotions.

“Oxytocin will not be a cure-all for mental illness or drug addiction, but it may be of use as a supplementary treatment. It may make individuals better equipped to interpret the signals of others around them, which may improve how they function in social settings,” Leknes explained.

Earlier studies have linked oxytocin to improvement in social information processing ability in autistic children including a study published in Biological Psychiatry and research from Yale University.

“If it turns out that our assumptions are correct, then we may be able to come up with a simple treatment that would mean a great deal for people who find it difficult to pick up on the social cues of their peers,” said Leknes.

The study was published in the journal Social Cognitive and Affective Neuroscience