I don't think meds are always needed, but I think you would be most familiar with yourself and what works for you. I don't understand using mood stabilizers or antipsychotics as PRN (as needed) just because they don't work immediately, it takes some time for them to work, and it can be hard to recognize the beginning of an episode, so by the time you realize you need the medication, you're already compromised, and might even be in a place where you won't take the meds. The only time I've ever had antipsychotics as needed have been a very low dose of Seroquel (25 mg) and that wasn't for psychosis, it's only for sleep. I can understand using meds as needed for anxiety or sleep, because the meds usually used for those work immediately.