Facebook ultimately encourages you to carry out social interactions online with people who aren't physically present. It's very easy and convenient and next thing you know your eyes are glued to your phone so often that it starts to replace physical interactions. You go out and spend half your time texting instead of talking to the people you're with, or maybe you stop going out at all.
But we are animals after all, not buckets of bits, and physical presence matters. It directs attention, priorities, investment, it gives people unique opportunities to bond. Anyone who's had a long distance relationship can tell you that they're fraught with challenges because you just don't get to spend a lot of time together. So maybe socializing in cyberspace, while it has advantages, simply doesn't have all the benefits it has in meatspace.
For my part I now put meatspace connections first, and aside from work, my calendar revolves around meeting other actual humans in person. Even if we don't share all the same interests, maybe even if they get on my nerves a little, I lived most of my social life online for a long time, and I like meatspace better. My Facebook usage waxes and wanes and I don't feel it makes me depressed--but if Facebook relationships were all I had, I'd be practically suicidal.
I think that FB is a crutch and a mild vice. And like all vices, the solution is to replace them with something positive.
Sometimes I've thought about what could replace this. Maybe some updated version of the Rotary Club/Lions Club/etc?
This raises the question of why antidepressant use rised this way. Could it be that heavily medicated people are easier to manage and keep under control to prevent them from rebelling against the lives they're forced into by the societal system ? Could it be related to huge profits from pharmaceutical corporations ?
Then again Facebook and the computer as a machine middleman in human interaction is destroying social interaction and society fabric by replacing actual meaningful interaction that builds human ability to be human. Not the single cause but a recent and efficient accelerator of a trend that push us further apart from each other.
I recommend watching the following BBC documentaries by Adam Curtis:
The Century of the Self[1]
The Trap: What Happened to Our Dream of Freedom[2]
All Watched Over by Machines of Loving Grace[3]
[1]: https://en.wikipedia.org/wiki/The_Century_of_the_Self
[2]: https://en.wikipedia.org/wiki/The_Trap_(TV_series)
[3]: https://en.wikipedia.org/wiki/All_Watched_Over_by_Machines_of_Loving_Grace_(TV_series)Except for antibiotics and simple surgeries, which are basically miracles on demand, most medical treatments don't offer great odds. Antidepressants do work, just not very well or reliably. We won't leave people to wallow or die though and have a need to do something for them. This is something.
However, it does indicate that people were battling depression before social media and its rates were increasing rather quickly.
That needs a great big giant source. Because there are so many peer reviewed studies and meta-studies that show that they are effective.
It does look associated with alienation, so does travelling alone, but social media use is probably a result of loneliness, an attempt to connect however feeble, not its cause.