The number of friends a teen has on Facebook can adversely affect a teens stress levels, according to a recent study.

Researchers from the University of Montreal and the Montreal Mental Health University Institute found that having more than 300 Facebook friends increased teens' levels of the stress hormone cortisol, Fusion reported.

"We were able to show that beyond 300 Facebook friends, adolescents showed higher cortisol levels; we can therefore imagine that those who have 1,000 or 2,000 friends on Facebook may be subjected to even greater stress," Sonia Lupien, who led the study, told Reuters Health.

On the other hand, teens who act in ways that support their Facebook friends -- for example, by liking what they posted or sending them words of encouragement -- decreased their levels of cortisol.

"While other important external factors are also responsible, we estimated that the isolated effect of Facebook on cortisol was around eight percent," Lupien said in a statement. "We were able to show that beyond 300 Facebook friends, adolescents showed higher cortisol levels; we can therefore imagine that those who have 1,000 or 2,000 friends on Facebook may be subjected to even greater stress."

For the study, researchers recruited 88 participants between the ages 12 and 17 years old, CBS News reported. The study participants were asked about their frequency of use of Facebook, their number of friends on the social media site, their self-promoting behavior, and finally, the supporting behavior they displayed toward their friends. Along with these four measures, the team collected cortisol samples of the participating adolescents. The samples were taken four times a day for three days.

"We did not observe depression in our participants. However, adolescents who present high stress hormone levels do not become depressed immediately; it can occur later on," Lupien said. "Some studies have shown that it may take 11 years before the onset of severe depression in children who consistently had high cortisol levels."

The study, detailed in the journal Psychoneuroendocrinology, is one of the first in the emerging field of cyberpsychology to focus on the effects of Facebook on well-being.