I have a very similar (probably unoriginal) thought about some human mental illnesses.

So, we VALUE creativity, we claim that it helps us solve problems, improves our understanding of the universe, etc.

BUT people with some mental illnesses, their brain is so creative that they lose the understanding of where reality is and where their imagination/creativity takes over.

eg. Hearing voices? That's the brain conjuring up a voice - auditory and visual hallucinations are the easy example.

But it goes further, depression is where people's brains create scenarios where there is no hope, and there's no escape. Anxiety too, the brain is conjuring up fears of what's to come