Hi dp! Psychological testing allows a psychologist to determine the avenue of therapy you need... depending upon which test(s) you take will depend upon what they are "testing." Yes, some testing is a good overall view of your current psychological makeup (like the MMPI) It's not really a "test" but called an "inventory" as there is no "failing or passing" it just is.

With MRIs they are making sure you don't have any physical brain injury (assuming they are MRIing your brain ) showing up... which could be giving you symptoms similar to non physically induced symptoms. You would still need therapy if you did, as you would need to learn to compensate and adapt to this... But some easier word testing will help determine if you have brain damage..

Let your T decide if you need testing.. often they can help without having to put you through such anxiety! TC