splitting can be a psychologists term for what we all (or most if us) go through during our development. separating good from bad and closing off/hiding emotions can be deemed as splitting.
split personality is not the same as schizophrenia if that is where you are aiming, but it is a multiple personality syndrome. msp is a psychiatric disorder that causes the sufferer's personality to divide into sub personalities, also known as alters. The alters have their own memory, and don't know of each other's existence.