I recently watched a documentary on a tribe with very little outside contact, anyways most of them committed suicide before they grew old. Suicide was accepted in their culture, mainly because of their religious beliefs. It was pretty strange...
I don't think suicide is cowardly or anything, although it is selfish due to your loved ones having to suffer. But then again isn't it selfish to want a person that is miserable to continue their existence?
Some people suffer from mental disorders, anxiety, depression, bi polar, schizophrenia etc. imagine having repetitive negative thoughts about yourself, these aren't "aww poor me" these are more like "I hate myself' thoughts, how many times have you truly hated yourself? Or being too nervous to even say a word to another human being, being paranoid that someone is out to get you, feeling worthless like everyone is better than you no matter how much you've accomplished, etc.
Take Ricky Hatton for example, losing to the best he felt like a failure, like he let everyone down. This guy probably thought about that every single day, it can drive you insane.