Actually, it's really difficult to change our entire surrounding instead we need to change ourselves to adapt the surrounding. Yes, suicide is definitely not an option but depression is something which unfortunately leads to such actions and thoughts.

My friend has just killed him self over been bullied

There are some people who feel so helpless and they think they can't do anything to repair their life and their surroundings. That is why they kill themselves

Very true! Killing is not an option for every solution. There is no problem which has no solution. Moreover, if she was going through so much of pain is should have shared that with her mother. As we can see in the series, Hannah's mother was more like a friend to her and sharing things with friends makes reduces pain. In addition to this, her mother could have taken her to some doctor or could have done something to get her right.

----> But at last, suiciding is wrong. It only causes problem and pain for friends and family to leave behind.