Stress? The modern world is a very stressful place, particularly for teenagers.
Also, I don't know if they glorify depression and self-mutilation; it's more of a coping mechanism. A bad one, but still a way of coping with the issues in their life.
I agree, it's a coping mechanism and a cry for attention.
Today the youth are often raised by a third party, with both parents working.
Parents get home from work, tired, watch tv/internet and are too happy when their children don't demand extra attention by remaining occupied with activities like tv/gaming/internet.
Slowly the depression sets in, because many parents fail to realise that their children would have liked to talk about things, would have liked to do activities, would have liked a closer more caring bond.
By the time the child hits the teenage years, it is too late,
the child has created a cordon and has developed their own
coping methods and mindset.
Emo's are simply emotionally sensitive individuals who prefer a closer bond with others, and almost all the emo's I've met, had disinterested dads or parents of which one was an alcoholic, cheater and druguser.