Lady macBeth is a great example of the psychological effects that murder can have on a human mind. At first Lady MacBeth is fierce, relentless, and almost male in her driving ambition. She thinks her husband is too "full of the milk of human kindness." Her greed and avarice is at its apex when she calls for the spirits which tend on mortal thoughts to "unsex her here" and fill her up with the cruelest and direst thoughts. After the murder, which the previous poster has intimated, she begins a psychological deterioration. She still is strong, however, and it isn't until the sleep deprivation and the sleepwalking (washing) occurs that she turns into a mere shadow of herself. We see a complete negation of her wild spirit in her suicide--that is her way of escaping the guilt and her blood stained conscience.