Do you mean after PGY-1 year or after intern year, and another year of psychiatry?
You can do WHATEVER you want with your license. You may not be able to purchase malpractice though. I mean, I can decide I want to do brain surgery, but no insurance company would sell me malpractice, since I have not touched a scalpel since MS3 year...
That being said, seriously, you need more training. Even after residency, you still need supervision to get better at this work.