In this view, JP Sears gives some pretty good advice on how become depressed:

It should be noted that he concentrates on the things within one’s control. The death of loved ones, loss of a job, etc. would all work too, but they’re outside of one’s control.

Oddly, fixating on the possibility of them would probably help to get further depressed, then, but he forgets to give the advice of focusing only on what one cannot control.

No one’s perfect, I suppose.

(NOTE, SINCE INTERNET: this is all humor.)