You're arguing with the discussion section in the bottom. But in the middle, there's analysis on researches that made a clear experiment. Researchers asked students to restrict the usage for several weeks, and they showed some effect, while the papers where restriction lasted only one week, showed no change. This is rather clear evidence of causation.

It sounds like you're projecting your own beliefs onto teenage girls. Even if they cared about income inequality or climate change as much as you think they do, that's still the fault of social media. It's counterproductive to be overly worried about something that is outside your control, especially when it doesn't affect you yet. Everyone is going to suffer the effects aging and death, so it's a very logical worry. However, if social media is filled with reminders of sickness and death, which is causing you anxiety, then you should quit.

> The economy didn't get better for everyone, in fact inequality rose starkly

What is your source for this "fact"? There were no drastic changes in Gini coefficient in the USA.

Also, I'm pretty sure suicide rate was also increasing in wealthy households.

> How about climate anxiety/eco-anxiety?

Do you really believe teenage girls have "climate anxiety"? Is there anything that indicates people suddenly became more aware of climate change in 2012? (the only spike Google Trends has is around 2007).

> people in Western societies don’t kill themselves because of wars or collective threats

The dozens of French white teens who joined the war in Syria in 2015.

The thousands of English teens who freely enrolled against Franco, the dictator who took over Spain in 1936, while they absolutely didn’t have to, as it was not part of the conscription? And if, once there, they deserted, they were legible for the death penalty.

While underage. Indeed, many examples of teens engaging into collective theoretical threats.

Just as some young men ride motorcycles at 200mph or free climb cliffs, others travel around the world to join wars that have nothing to do with their family or community. I would be very cautious about ascribing noble motives to reckless death-seaking behavior like this.

And girls. There are examples of underage girls engaging in the 1936 Spain war, trying and succeeding to pass as teenage boys.

I would argue, that the economical situation is not very influential on kids and teenagers. Having friends and hanging out with them, is much more important. Kids don’t need a lot. As long as they have food, clothes, a place to sleep and go to school, it should be okay-ish. They don’t need to go to the cinema to have fun, they can just meet up in a park or play soccer/basketball to have a good time.

> The economy didn't get better for everyone, in fact inequality rose starkly; this might be a correlating factor.

One thing that I thought about this is that while unemployment might have been low, both parents were more likely to be working.

Raising sexual harassment and rape rates can be contributing factor too. The boys commit more of those last years.

My understanding is that if you hold both the definition of rape and the ethnic origins of the boys constant rape has been going down for decades. Is this compatible with the evidence you've seen?