Grad school starts with horribly boring, tedious, and make-work intensive classes that are generic to all NP specialty (actually all MSN) areas: more "advanced" nursing theory classes, more policy classes...an "advanced" assessment.....a good set of classes on evidence-based practice (to try to get you to volunteer your time to help the PhDs as a scut dog worker on their research projects). There's advanced pathophys, ignoring the entire brain except maybe Alzheimers......Typically, there is a generic "advanced" pharm class, but it is at the level of a pre-nursing-school med class: it will not help with prescribing at all, and is a bunch of make work that is more appropriate at the undergrad level. Oh, and it doesn't necessarily even COVER psychotropics. Nice, eh?
After that, some specific classes, none of which will help you as a PMHNP. Usually the classes are make work, group stuff full of games and posters. The internships, if you're able to get good ones, are the only learning experiences in the entire program, but they won't help you in your job as a PMHNP.
See, PMHNPs are meant to be prescribing machines in the hospital or O/P setting. Revolving door kind of thing. Drugs only! Schools focus on psychology, learning theory, change theory, etc.......every kind of psychotherapy for individuals, groups, and families. But in reality, the JOB of a PMHNP, if you can't have your own practice (good luck with that!) is going to be 100% prescribing. you will not be ALLOWED to do any kind of therapy.
So, basically, when you look at the mismatch between the education and the actual job, it's huge. There aren't even med classes that cover psychotropics. Difficult to imagine, isn't it?
As for the DNP, it has more of the exact same stuff, nothing really adding to what you know. Oh, they do tout the "management" classes - as if you should have to do 2 more years of school, and 500 more same-old-same-old internship hours just to get some "management" classes: i.e., nothing really beneficial, except an ego-sop "DNP" after the name, if you're someone who needs that....and it doesn't sound like you are.
Basically, if you're interested in quickly seeing patients and prescribing to them without really knowing them, do the PMHNP program. If you want to actually talk to them, do some CBT, etc., you'll have to either have your own practice (! taking me years to get even a part-time practice going in this economy!) OR become a psychologist (PsyD or PhD) instead. Or get the MSW, social workers earn more than NPs anyway, and get to talk with patients more.