Doctor switching one of my meds

Apparently, antidepressants provide pain relief. Or affect some receptor in tbe brain so that one doesn't feel pain as badly. The doctor has decided to try a different one out. Now, when they ask you, when you are at the hospital, to put a number to your pain, do they factor in antidepressants, such that a 9 automatically becomes a diff number? And what about the poor guy who is drug-free and in pain? Does he get a different scale than me, altogether? I wonder about these things.