Psychology is literally the study of the soul and life, but has been more recently understood to be of the mind and behavior. The closest science may be behavioral as "mind science" seems undiscussed, but topics named science refer to themselves as a science not that they are practicing as such, but so as to avoid through an appeal to the language authority the possible argument that they lack it. If a Greek derivative was desired for the study of the mind, then it might be dianoialogy.
This is really eroding public trust on real science.