Psychotic disorder that could suddenly recur-is it disqualifying?

I'm asking this mostly out of interest, not for myself.

In January, my sister had an sudden, rapid-onset episode of psychosis (she went from normal to severely delusional in 12 hours) that was not drug-induced. She completely recovered just as rapidly about a week and a half later. With her specific diagnosis, doctors are unsure if antipsychotics prevent new episodes.

So let's say her episodes happen about once every year, meds or not. Is this a situation that can be mitigated in the eyes of clearance adjudicators?