Being mentally ill doesn't make you crazy:
Being crazy involves living outside your limitations. Attempting things that aren't in your skill set. That's irrational.
If you are mentally unstable, but make accommodations for that, you're not insane. Just wounded.
It's not really all that common, though. Most cognitively affected people also have sensory deficiencies, so they don't perceive the problem, and therefore don't compensate for their disability. That's really pervasive.
Oh, and Trump meets with Putin on Friday.