They are always counseled to drop out of 4th year immediately and set up their research gig then (starting in, say November - August of next year). It's best to hold on to your student status as long as possible, both for the basic benefits (insurance and so forth) as well as the immeasurable boon of applying to the match as a US senior rather than an independent applicant.
If you do like your chosen specialty (psychiatry in your case) obviously the advice still holds, though you'd have a tougher time justifying it to your med school dean and to residency PDs next year.