Psychosis lifted?

Dad has been in a period of Psychosis since his surgery. He believed he was being held prisoner at the hospital. He called 9-1-1 and the police. He was agitated for hours on end. Hateful. Spiteful. Mean. One thing he kept asking for in this state was his Ukulele. He has been unable to play it because his fingers were numb because of his spine. The surgery was supposed to relieve the numbness. I brought the ukulele and he played it! This was NOT the end of the Psychosis, just a respite. Somehow his years of being a musician took over. He became a performer again. Then, he transformed back into that awful state. The brain is a strange organ.