Having a big friends list and expecting many likes from them on posts, can cause stress among adolescents says a study, conducted by the researchers at the University of Montreal and Institut universitaire de santé mentale de Montréal on teenagers aged 12-17 years. The study found that having more than 300 friends on their friends list increased the levels of the stress hormone, cortisol in them. On the contrary, if they showed their support towards their friends through likes and comments on their statuses, the cortisol levels reduced. The sample size were judged on their frequency of Facebook usage, their self-promoting behavior and the supporting behavior of theirs towards their friends.
Other studies have shown that high cortisol levels at 13 years of age increase the risk of suffering from depression at 16 years by 37%. Read the study here.