Four years med school, four years residency. Low bar to entry and can be extremely family-friendly after internship. Depends a lot on your program but overall it's absolutely one of the cushiest residencies. Typically your intern year is a mix of medicine, neurology, and a little bit of psychiatry, with call duties reflecting those of the other specialties. Second year is mostly inpatient psych, and third and fourth year focus more on outpatient work.
We had a night float system for calls which worked out to about 2 evenings or 1 weekend day every two weeks plus two weeks of nights in the second year, 2 evenings or 1 weekend day every month in the third year, and the fourth year was call-free (though that may be changing).
I think psych is the hidden 'lifestyle' gem of medicine (never mind the subject matter is totally fascinating) and don't understand why it isn't more popular/competitive than it is. I love it.
if you are already an MD, i'm guessing you could enter as a PGY2 which would not make it bad. and, if you're already an MD then i'm sure you're used to working hard.
i don't know, i don't have anything to compare it to but for me, residency has been tough, even in psych. my program is known for high volume, so i would check out carefully the program you are going to. it only takes so many suicidal patients to learn how to do an emergency evaluation, and if you are going to be worked as a service horse at a particular hospital, i might look elsewhere because after a certain point it's just not 'learning', it's servitude. particularly if you are already in another field of medicine, I would be very discriminating.
but in general. . i think after residency I will really enjoy the field. and you really have the funniest stories to tell your friends about your patient interactions.