That being said I do think you're right. It's just that there's two underlying trends here of "mental illness". The one your addressing has been longer term and more pervasive while the recent trend is, as stated, a new trend and seemingly caused by social media.
Social media is definitely a factor. I was still in the generation where we had social media, but phones had no or very shitty cameras and mobile internet was too expensive for us teens. Some people didn't have phones, period.
But those kids have a constant comparison to ideals, especially the girls, be it their peers or celebrities. And if there is mobbing it is way, way worse than in my generation, because it is easier to have a true all against you situation (with many passive bystanders) and because it doesn't end when you are at home.
Definitely agree.
> Evidence points to the fact that the structure of society is not causative of a new trend we are seeing.
Trends can't exist without metrics. What's recent are the observations of the behaviors and new politics and moved goalposts, not the behaviors themselves.