Imagine falling into a chasm. Near the top, there are ledges to grab onto and the walls are pretty close together, but as you fall more, the walls get further apart and there are fewer ledges. You get scraped up (cutting) more and more. As you fall, you go faster and faster. You'd think you'd reach terminal velocity, but it never happens. You just speed up more and more. The bottom of the chasm is suicide and the ledges represent healing from it. It's easier to crawl back up the further up you are.
That's depression.