I did forget to address your issue is "threat".  To answer that simply, is YES.  Almost all bi-polars will blame and threaten those that they blame or feel anger towards - and usually will threaten them at some time.  Will they act upon those threats - that's a tossup.  Just recently a young man you was diagnosed bi-polar killed both of this parents (in the U.S.) - but I would say that it is a smaller percentage that do act on threats than those that do - at least to the point of harm or death.  However, they are very good at psychological warfare and will do their best to cause mental harm to those around them, and they do it often and with almost a pleasure about it, as they really don't understand why they are the "sick" one, so it must be "your" fault.    If you have a family member or friend that has one of these diseases, I highly urge you to run (don't walk) to your nearest social services department for your state or government, and ask for a "family support group" that you could join.  Those that have been living with this disease in their lives are the best to give you the support and answers you seek.  God bless and good luck.