But I for one would not ever get myself involved with someone so negative or insecure again, someone so unwilling to take responsibility.
Isn't there the danger here of failing to recognise the genuinely medical nature of these conditions in a lot of cases? I doubt you would talk in the same terms about someone with cancer, or a serious disability. If you acknowledge that mental-health disorders are just that, then it simply doesn't make sense to talk in terms of responsibility.
Now, I'm not trying to poo-poo your experiences here. It may well be that this person was not someone you could help, that her state of mind could only negatively affect yours, and that your continued attentions might only have made things worse. You're probably right about this person. I just think that talking about mental health issues in terms of 'responsibility' is very dangerous.
I was attached at the hip to this girl for 5 years. And by "take responsibility" I mean recognize your own insecurities and not force them on everyone else. For example, just because she may hate the idea of having a boyfriend because she couldn't get close to a guy in any meaningful way doesn't mean I should not date either. She thought that I was not invested in our friendship even though I'm the one who drove to her house (an hour away) every weekend because she was too scared to drive. This girl seriously thought that because I didn't want to kiss her feet, that I didn't love her (nope, definitely not kidding). She was just fucking crazy and only got worse by refusing to acknowledge her problems.
That's what I mean by taking responsibility. It is an illness that she can't change on her own, but she needed to recognize that she had problems and stop trying to medicate/self medicate them away and blame everyone else for her unhappiness.
Even though she was my personal terrible experience, I also knew those just like her thanks to my fantastic alternative high school, who chased away everyone who tried to get close. Teenagers and young adults that are heavily medicated for mental illness are nearly impossible to be around and ultimately it's for the best to just not get involved.