Hey.
I took geography and psychology. I would say that I didn't really notice the case study side of things because the case studies are so completely different for the two. Also, with psychology, the case studies are taught as the content rather than the extra like you get in geography so really there is very little extra case studies you need to know for psychology unless your teachers go out of the way to give you extra which really isn't needed. psychology is really a subject where everything you need to know is in the textbook.