My sister was born before her month. So, she had delayed mentality. Now she is 19 years old. While she was 15 she got kidney failure so, she got to scream a lot during dialysis( she was panicking or feeling pain). when she was 17 years old she got kidney transfer; However, she got the habit of screaming over anything; aggressively screaming; sometimes out of nowhere if she was alone she screams. how can we stop this? a doctor here describe Risperdal but we're worried about the side effects!