Once in the hands of a psychiatrist or psychologist people start to lose hope for the future, when hope for the future is gone the person sees nothing to live for.
This is what I see as the biggest side effect to these treatments of drugs and/or therapy -- the losing of hope for the future.
Its pretty much universal with patients of these two professions.
There is actually a statistic on the number of people that commit suicide within a couple of hours of having been to a counseling session.
Can't remember the specifics off hand, but I remember that it was hard to believe.