[ars]

I agree. The best way to deal with true depressions (which is not caused by circumstance) is to simply do things.

Anything. (But not passive things like watch something, or read something.)

Make something, drive, hike, volunteer, clean, garden. Whatever.

You can help them by thinking of what activity they often do, and doing it with them. But remember to think of what they do, not what you do.