I've had a few of interviews...
The questions have been the same.
1. Why did you choose psychiatry?
2. Why did you choose our program?
3. How many programs are you applying to?
4. What are your other interests?
5. Do you have any questions?
6. One interviewer asked me if I couldn't do psychiatry, what would I do...
Be prepared to explain any "abnormality" in your transcript. Such as; a poor grade, leave of absence, etc.
That's about it. They've all been pretty benign and spend most of the time answering your questions and trying to sell their program.