To me, your question is vague. I'm not exactly understanding what you are looking for, but I'll make another guess: you want to know what I believe is the "mechanics"?
Okay this is what I believe (and no I dont have any 'training'") to be some of the mechanics:
1. Social media increases the exposure of your "wants". People show off their new stuff, the nicest pictures from travels, their new clothes etc. By constantly feeding yourself with the "success" of others, satisfaction with what you already got decreases, and trying to get where your "successful" friends are increase stress & anxiety.
2. Social media share all of the great skills of the world. Back in the days you could compare i.e. your guitar skills with your closest friends, and of course you'd see Hendrix as your inspiration, but you wouldnt compare yourself to him. Today you watch some four year old kid singing the greatest opera of all time and you think: I'll never be as good as her and she is just a random kid. By comparing yourself to the rest of the world, you get self-defeatist in your views meaning what used to be your passions and interests become burdens, since you know you'll never be as good as the dude in the Youtube video or whatever.
3. The concept of participating in or just looking at constant communication create feelings of loneliness. What you pericieve is that the whole world is always communicating but that you are no popular enough, since you dont feel popular. You ignore the fact that lots are feeling the exact same way: they are communicating, yet lonely. Because that chat message can never replicate that face to face communication, even though some parts of the brain react similar to both stimulations.
I could go on endlessly: how "likes" are transforming previously genuine interaction to be social transactions. How feeding yourself with "news" 24/7 creates immense anxiety over future, and how equally constantly feeding yourself with nostalgia creates depressive thoughts of what have been lost.
It goes on, but I think you get my point - whether you agree or not with these examples - that I'm not just pulling numbers & graphs out of my ass. I have read a lot on this topic and I have been thinking about this subject since I got Internet at the age of ten and immediatly thought "damn, everything that was is seriously endangered by this shit".
Great answer. Thank you for taking the time to write that.