I have my ADN with no BA in any field, and there are programs out there for this specifically. But you do not need to go for FNP or ANP in order to get the psych. If psych is all you want to do, then just do that. You can always go back and get the post master's in another specialty if you want. What I would look into is what other NP options the schools
you are looking at has, so that way if you do want to go back for a post master's, then you can be sure all your credits would transfer.
Also, if you MSN is what you want (like me), I see no point in getting a BSN, whether seperately or as a part of a bridge option. It will only add more classes. The ONE benefit is that if you think you might have to quit at some point, you would at least get to keep your BSN that you earned. With the "no BSN awarded" option, if you quit, you get nothing... no BSN, no MSN. To me, this is just more encouragement and incentive NOT to quit.