I don't believe any part of Vinnie's workshop goes into determining if a person has a mental illness.  What it does go into is whether a job candidate has the correct personaloity traits to work in the sometimes highly stresssful field of Histology.  Not every person posssesses the ability to "fit in" in our labs.  We usually have to have the ability to work as a team, communicate effectively, make critical decisions, work under stress, be self motivated etc., etc.  
As far a having the potential for violence, there are some indicators and situations that may make the probability increase.  Discrimination is not the issue.  Supervisors need to be aware of an employees emotional state as well as their work.  Its no different than being aware of an employee who is having personal poroblems that  cause them to make errors in thier technical work.  A supervisor should be just as aware of an employees mental state that may cause him/her to injur or become injured.  
Jan Mahoney