Bersaguy,
I don't say this out of spite or meanness but I can't fathom the fragile psyche of a man that is irrevocably damaged and depressed just from some tests and worry. I get it while they're in limbo waiting on the results but not enough to permanently damage them for the rest of their time on this earth.
There are different reasons that these tests can be shotgunned out...some good, some bad. Remember that we live in a litigious society, making a diagnosis isn't an exact science (counter intuitive, I know), symptoms and signs often overlap and share similitude, etc, etc, etc.
Bottom line is that if you notice something abnormal (or think you do), you have to rely on tests, judgement, training, and skill to get to the root cause. Nothing is 100% in medicine.
Not to sound all knowing as I'm sure there are Doctors and Nurses in here that would run circles around me. I'm just getting started in my BSN so I'm at the point where I know enough to be dangerous. I hope your friend can adjust and get his personality back to square one.