Cait Irwin Liane speaks with 19-year-old Cait Irwin, who has written a book entitled "Conquering the beast Within: How I Fought Depression and Won... and How You Can, Too" (Times Books). Six years ago, Irwin was so depressed she nearly committed suicide. She was hospitalized and given medication. As part of her recovery, Irwin started writing about her illness and drawing her depression in the form of a mongrel-like dog character, which she called "the beast." She used the technique to separate herself from the illness of depression so as to gain control over it.