Are people who draw abstract paintings mentally ill?

There's a fault in your logic; nobody can draw paintings.  I think that your question is if people paint paintings.

Some of them are, some of them aren't, just like any other type of art form.  It's like asking if only 'normal' people paint realistic paintings.  I couldn't draw a realistic drawing or painting if the world depended on it, and I'm 'normal'.  (I'm assuming your definition of normal; everybody's different, there's no such thing as normal, but I think that I can understand what you're trying to say.  And that leads to the question of what a 'mentally ill' person is.  Do you know?  I know the official meaning of it, but is there such thing?)

Creativity is derived from the lobes of the brain.So far, science hasn’t really determined exactly what happens in our brains creative process. Since it really combines a whole bunch of different brain processes. And, contrary to popular belief, it includes both sides of our brains working together, rather than just one or the other.

The truth is, our brain hemispheres are inextricably connected. The two sides of our brains are simply distinguished by their different processing styles.

Interesting quote from the link below:

Scientists have long studied the link between creativity and mental illness, and the lines between the two are often blurred. Studies suggest that creative people often share more personality traits with the mentally ill than “normal” people in less creative pursuits. One Stanford University study compared patients with bipolar disorder with a group of healthy people. They found that graduate students in creative disciplines shared more personality traits with the bipolar patients than with their healthy but less creative peers, according to a study published last year in The Journal of Affective Disorders.

https://well.blogs.nytimes.com/2008/12/11/art-and-mental-illness/?_r=0

Let me ask you this! Are people who ask stupid questions anonymously stupid?

This question probably upsets you and makes you think I am harsh or mean......

Think about it for a minute.