If because of some recent mental health situation you cannot perform as good as before, should you mention it when applying for a position?
I don't think you are obligated to discuss health conditions with a potential
employer. Your references discuss your prior work and the importance of your research program. (To the extent they speculate about future performance is irrelevant.)

Go for your dream job and work as hard as you can. Allow your career to evolve as it will.  You shouldn't undermine previous effort by speculating about things that have not happened yet.