Not a good state of mind for painting (9)
I believe the answer is:
distemper
'painting' is the definition.
(I know that distemper is a type of painting)
'not a good state of mind' is the wordplay.
I cannot really see how this works, but
'a' could be 'per' (eg 'one a day' means 'one per day') and 'per' is found in the answer.
This may be the basis of the clue (or it may be nonsense).
'for' is the link.
Can you help me to learn more?
(Other definitions for distemper that I've seen before include "Paint; animal disease" , "Sickness" , "Kind of paint" , "Paint; canine disease" , "Paint; disease of dogs" .)