TzeLin, I like your mixing a fictional story with a nonfictional discussion. Your insight is valuable.
The best thing you can be for a person that is depressed is available and an example and source of light.
Most people's advice is trash. People tell you to suck it up, move on, and we ALL go through problems. I bet that talked someone off the ledge.
People feel invisible. Sometimes I feel invisible. So when someone sees me, it's special because sometimes it feels so rare,
Give a little of your time to someone. That is our wealth, Time.
It could be a random simple text saying hello; I was thinking of you and wanted to say hello.