<human>: Can you give me the gist of the text in a nutshell?

About 6 months ago, a very close friend of mine, let's call her Sally, confessed that she "used to" have a crush on me. I didn't know what to do/say, but since she said "used to" I just said "oh wow, that's very flattering." Two months later (4 months ago) she confessed that when she said she used to have a crush, she was lying and actually still did have one at that time. I didn't know what to do, so I just changed the subject, thinking that it was a thing of the past.

Anyhow, fast forward another two months, we are still friends, but nothing more. She starts seeing a therapist and eventually gets diagnosed with depression. I don't know if my rejecting her romantic relationship is the cause, and I hope to God it isn't. 

How should I interact with a friend of mine who is depressed and may still be interested in a romantic relationship? I have no interest in a romantic relationship, but I'm willing to do whatever it takes to help my friend get past her depression. I just don't know how to interact with her anymore now that she's told me she is suffering from depression.
<bot>: Friend of mine used to have a crush on me. She's suffering from depression and has confided that in me. I hope those two things aren't linked. I feel uneasy interacting with her. How should I communicate with her?