Having more than 300 friends on Facebook could be causing your teen unwanted stress, say researchers at the University of Montreal and the Institut universitaire de santé mentale de Montréal. According to their recent study, which measured each subject’s cortisol levels while they interacted with online friends, those with more than 300 connections had higher readings of this stress hormone than those with fewer contacts. It’s not all bad, though; those who interacted with their friends in a positive way (i.e. liking friends’ pictures, leaving positive comments and having healthy conversations) were able to decrease stress. Taking a week off from Facebook is another way to cut down on tension, found researchers at the Happiness Research Institute in Denmark. Those who took time away from Facebook felt happier and more satisfied with their lives, said researchers.