Thus treated, madam is unchanged (8)
I believe the answer is:
reversed
'thus treated' is the definition.
The definition and answer can be both related to change as well as being past participle verbs.
Perhaps you can see a link between them that I don't see?
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for reversed that I've seen before include "revoked" , "Overruled" , "Turned round" , "Drove car backwards" , "Put backwards" .)