My Brother, A Well Known Bolar Manic Depressive Was Prescribed

My brother, a well known bolar manic depressive was prescribed Zoloft without being grounded on lithium and he just died and according to neighbors and his roommate he was very psychotic. Not sleeping and screaming every night. He received this prescription from an online virtual Family Practitioner not a MD. Can Zoloft without Lithium in this case cause psychosis?