I've never been depressed before but I've been with someone who has and it was not really easy getting him to overcome it.
But the major thing we did was to always be there for him and also put him in prayers. Another way to overcome depression is to always try to be around people instead of isolating yourself.
I don't know much but I think if the victim can be around people, it will be of great help.
I want to submit this post to dreemport because I find it very helpful and useful, I hope you don't mind.