Both triggered and just happen. But I can never trigger the delusional stuff - it always has a mind of its own. It can come totally out of the blue - like, driving down the road and suddenly - I HAVE to stop because this cloud has a message for me. (When the universe talks to me I HAVE to listen). But mania and depression can be triggered if I am stable. If I am experiencing one or the other - they can't trigger the opposite one. Having anxiety also can cause them to be exacerbated.