Both Lady Macbeth and Esther Greenwood are emotionally unstable, but Esther recovers and Lady Macbeth does not.
Esther has a breakdown, which causes her to make all kinds of bad decisions and engage in risky behavior.
I guess I should have been excited the way most of the other girls were, but I couldn't get myself to react. I felt very still and very empty, the way the eye of a tornado must feel, moving dully along in the middle of the surrounding hullabaloo. (ch 1)
In the end, though, she is able to overcome her mental instabilities and interact with the world.
Lady Macbeth, on the other hand, takes the opposite arc. She begins strong and self-assured. Like Esther, she is ambitious. Unlike Esther, she is not alone. She is married, and she convinces her husband to kill so that he can be king. Once her husband kills Duncan, Lady Macbeth loses control of him and herself. She goes on a downward spiral that results in her own suicide.
Out, damned spot! Out, I say! One–two—
why then ’tis time to do't. Hell is murky. Fie, my lord, fie!
A soldier, and afeard? What need we fear who knows it,
when none can call our power to account? (Act 5, Scene 1)
Lady Macbeth can’t cope with the guilt of what she has done, but Esther really has not done anything to be so guilty about. She knows she should be happy about the internship she got to a fashion magazine in New York, but she isn’t. Instead she feels empty. Esther attempts suicide, but she is rescued and hospitalized. No one is able to save Lady Macbeth.