How to break up with a Depressed Girl?

I'll preface this by saying I know it's not your job to take care of her and all that. If you really want to break up, the best way is just to tell the truth and explain how you feel to her.

Alternatively, if you want it to work, you could try to be extra supportive and help her out, or help her help herself before you give up on her. If you're all she's got, without you she'll have no one. If you can get her to get help and to start working on improving herself, maybe you'll find you're glad you stuck around. It'll take a bit of work, believe me, but sometimes people just need a little boost or some help carrying their [figurative] load for a bit. It could even bring you two closer. She has to admit (and be diagnosed) that she's depressed and want to be helped for it to work fully. Just a suggestion though. I know its only been 3-4 months but its not impossible.

She is really a suffering person. Even as a friend, or even a stranger, wouldn’t you want to help that person rather than thinking of ways to let them go?

Just tell her you will still be there for her, be her friend. Shes on the edge right now, dont push her over bro. She looks like shes going thru a lot, dont be the thing that pushes her over that line. Tell her you will still be there for her.

Eeeehhh she won't. It's ok let her go. Just tell her that she will find another guy sooner than she thinks

How to break up with her without guilt? Talk to the Physician who diagnosed her depression before you break up with her.

Talk to the people she lives with.