If they are gonna listen to the same content often then that's a remedy for depression. So if their algorithim on their device keeps spitting out the same stuff I can see why. Or it's no different than listening to one type of genre too often especially songs that are down. They should take a break from social media or look into happier content to even things out.
I can easily see how Linkin Park or other artists could bring them down. Teenage years have lots of emotions with ups and downs.
Hopefully they don't see this video. I've heard it can increase visits to a therapist:
(BTW has no influence on me)