Pdoc is psychiatrist (can prescribe meds),
T is short for psychologist (aka therapist-- hence the "T"-- doesn't prescribe meds) and
GP (general practitioner) is what physicians are usually called.

Hehe, if you aren't already up to your eyeballs in new terms , there is also PNP... Psychiatric Nurse Practitioner, who can usually also prescribe.

(Sometimes Pdocs also do therapy, but that's pretty unusual these days.)

Study up, there'll be a test!