Celebrities open up about mental health:
Brooke Shields found comfort in knowing her extreme feelings were due to a chemical imbalance.
Catherine Zeta-Jones hopes that going public about her bipolar disorder will help to get people talking and remove stigma.
Lady Gaga knows that her sadness cannot destroy what is great about her.
Angelina Jolie has learned that in moments of depression, she has to remain active.
And Miley Cyrus isn't ungrateful, but she can't pretend to be happy when she's not.