I had my Bipolar One regulated effectively for 20 years with lithium. Then my mother died last year and I got a little hypomanic which made me less than perfect in my med compliance. Within a week I had spun into a full blown manic episode that required hospitalization. That is not to say that when I decompesate into a manic or depressed episode it is purely caused by circumstance. I've also become symptomatic for no reason at all except for brain chemistry. But I always keep aware that stressful events make me vulnerable to relapse.