This side-effect can have drastic results, considering over 1.1 billion users around the world are linked up on Facebook alone. 
The study monitored 82 participants’ feelings and well-being, compared to their social media use, over a long period of time. This kind of LONG TERM comparative research was the first of its kind to be conducted.
The main correlation result was: the more time spent on social media, the less happy you will be over time.
A separate study in 2010 conducted by Carnegie Mellon University discovered that when users are DIRECTLY interacting with social media friends, such as posting pictures and status updates, tagging photos, or liking things, their sociability and well-being increased.
However, the dangerous part of our social media use stems from the time we are passively consuming social media content, which represents a majority of user time spent on these platforms. This passive consumption of other peoples idealized vacations, days off, meals, boyfriends, family, etc. led users to feel lonely and unsatisfied with their own lives, despite how eschewed this perception of others lives ACTUALLY is.
Thus, social media has forced us to face a grave paradox: social media claims to be the platform that can connect users with their friends, family, community and the like within seconds, and this is true; however, never before have we experienced more isolation than we are now as a result. Our obsession with our digital social media lives is beginning to take precedence over our physical, here-and-now lives, resulting in our inability to interact with real people, and enjoy life’s current moments without being distracted by how this will be portrayed on social media.
Sources: Daily Mail