Two personal instances and one I've read about:

(1) In college, I went to a psychiatrist at the student health center. (My parents were all ca-ca-pants about him because he'd treated the football team's quarterback for performance anxiety! ) It took him sixty seconds to run down a laundry list of symptoms. The ONLY thing that stopped him from diagnosing bipolar ("manic-depression" back then) was that I had no sleep problems.

(2) A musician friend of mine was "diagnosed" as bipolar in even less time -- his psychiatrist just arrogantly assumed that all artists were.

(3) I understand some HMO's expect their shrinks to diagnose via "decision trees." These look like computer flowcharts, with only yes-or-no questions re symptoms. The doc is to arrive at a diagnosis in no more than fifteen minutes, and he/she is penalized for taking longer!