Do you tell someone who's mentally ill that they're mentally ill?

Or do you just leave them to wonder why you’re treating them a certain way—such as not believing their stories or taking their bizarre notions seriously—and not wanting to deal with them when they’re all in a spin or acting freaky?

Maybe that’s a professional’s job, not a matter for lay judgment, but what if they won’t see a professional?

Amateur attempts to help can do damage, as well as resulting in a lot of stress and frustration. But you can’t just live with a crazy person and try to act as if everything’s normal, right?—because unpredictability, volatility, and even the risk of personal harm can come into that picture.

And it can just tear a person apart to see a loved one go through the anguish and pain, knowing they can’t really help at all.

Practically speaking, what do you do when someone you care about is off balance mentally and you have essentially no power or influence over them, or if you do, you don’t know how to use it?