According to the Kaplan bank, the majority of "difficult" to answer behavioral questions are really in the realm of pharmacology. Ethics questions only have a handful of "exceptions" rules to know, and then use your common sense. Psych diagnosis is something you need to learn, but pretty straightforward with a slight twist here or there. But Kaplan lumps all the pharmacology to treat behavioral and personality disorders into the "behavioral" category. If you know your pharm, then that should include the anti-depressants, anti-psychotics, etc., and that would seem to be half the battle.