Why doesn't bother many Americans that a man with an undiagnosed case of PTSD possibly be the next president?

With all do respect to Mccain....and I am not saying he does have it but being in vietnam and being a POW it is possible that he could have the disease that ails so many of our soldiers and I think that could definitely affect his judgement on running america....and as an american I am scared of the thought of him being the next president.