Are you saying one should not sue, or at least weigh heavily, people's mental state prior to launching a lawsuit?
Is that current procedure, run mental evaluations before suing? Lots of people have mental breakdowns before and during trials. The trials proceed so long as people are 'mentally competent' to stand trial.
If something like this were allowed, people would pretty much abuse the system and claim mental anguish, etc. to avoid facing a trial.