A Very Controversial Diagnosis
The Skeptics
As a graduate student, your professor was taught that "multiple personality disorder" (now
called, Dissociative Identity Disorder or DID) was so rare that it was unlikely a clinician
would encounter a legitimate case of it in a lifetime of clinical practice.  That really was okay,
because the way the disorder was described, your professor thought the treatment for the
disorder must be very complicated and sort of like working with a dozen clients simutaneously.
During the early 1990s, a client your professor had seen for 18 months entered his office
appearing like a completely different person.  He was flabberghasted.  The psychiatrist at the
mental health clinic, tried to convince your professor that this woman was "faking" it and just
wanting more attention.  Within a week, the client needed to be hospitalized and was diagnosed
as suffering from a dissociative disorder.  This hospital was very conservative and not
enthusiastic at all about making the diagnosis, but her behavior could not be explained by
another diagnosis.  When she was discharged from hospital, your professor wanted to refer her
to a clinician who specialized training.  She refused to "start over" with another therapist and
insisted that he get trained right away.  The point here is that your professor was absolutely
NOT looking for someone to diagnose with this disorder.  And, if you imagine that it must be
fun to see someone talks using different voices, you are mistaken.  These clients have been
subjected to the very worst acts perpetrated by humans and constantly relive in their minds
experiences no one in their right mind would want to think about, much less hear about.  
Furthermore, they almost invariably suffer from serious thoughts about suicide. Below are some
lengths to what skeptics and compassionate professionals say about these disorders of extreme
stress.
DID: A valid disorder