Not that you don't, but this is the biggest reason psych left a bad taste in my mouth from my medical school. You see, regardless of why they came, from full on schizophrenia to simple, uncomplicated substance abuse, we were required to perform a 30 minute interview, with each part of it having a defined time frame. So there were at least 2 occasions where I had to spend a half hour with someone who wouldn't respond to questions verbally or physically as they were catatonic, and others where you would ask one question only to have them speak for a half hour, ignoring any redirection.
I always hated that.