It honesty just depends on the bands. some of them help teens who are depressed through it. Some are just there to sound cool. Most people just think its a bunch of noise until they look at the words of the songs. A lot of them talk about hard times and some talk about heartbreak. For example:
I Prevail- scars. It talks about the scars that people deal with, their depression, anxiety, fears.
Korn- Take me. Can be thought of in many ways but it has helped many people when they are felling down. But many people believe that it is about the singers alcohol addiction calling for him everyday to drink after being 18 years sober.
Pierce the veil- king for a day. It talks about people who are over others not caring for them. and they don't want to deal with it anymore. To imagine a better life.