My first diagnosis was Mood Disorder NOS but my pdoc didn't know my history, it was just based on my symptoms when I went IP. After we sat down and talked a little more he diagnosed me Bipolar NOS in about 15 minutes. He was my pdoc for the next 2 IP hospitalizations, 2 PHPs, and now outpatient, and he is firm in his diagnosis. If the pdoc is able to get enough history in an hour, then yes, a diagnosis is possible.

Most pdocs that I see for the first time tell me that their initial diagnosis is subject to change (unless they've had me go through testing).