I'm not buying the gun argument. Guns were just as available... perhaps even more so when I was a kid, yet I went to a school where we didn't have metal detectors or an assigned cop stationed at the school.
There was just as much bullying... and just as many fucked up parents.. and mental illness... and even less awareness of it than there is today, so I'm don't think it's because people are more fucked up today.
Only two things seem to have really changed since I was kid. Where we had ~4 billion people on the planet, we now have 7 billion. And where an average person had an opportunity to grow up, get an education and a decent job and be able to afford a comfortable life and a family, now an average kid has very little to look forward to.