My teens are watching the show and I agree with you that it’s an important topic that needs to be discussed. I also agree that Hannah is mentally ill (or perhaps she’s the only sane one in a crazy world…a matter of semantics!).
However, as a mother, I also understand people’s concerns. When a person — especially at that age — commits suicide, it makes it easier for others to follow suit. Sadly, these things do tend to go in cycles. And I don’t know that watching the show will necessarily cause many teens to open up to their parents about the issue or seek help.
I think the answer is not to avoid the show, but rather for parents and kids to watch it together or, at the very least, watch it separately but be sure that the parents keep up with the kids’ viewing. Parents should be aware of the issues concerning teens today, and the signs to look for in a kid who is suicidal. And most importantly, they should ensure that they have open, non-judgmental lines of communication.