Imagine you are attending a party with Abraham Lincoln, Theodore Roosevelt, Robert Schumann, Ludwig von Beethoven, Edgar Allen Poe, Mark Twain, Vincent van Gogh, and Georgia O'Keefe. Maybe Schumann and Beethoven are at the dinner table discussing the crescendos in their most recent scores, while Twain sits on a couch telling Poe about the plot of his latest novel. O'Keefe and Van Gogh may be talking about their art, while Roosevelt and Lincoln discuss political endeavors. But in fact, these historical figures also had a much more personal common experience: each of them was dealing with depression.
Depression is an illness that involves feelings of sadness lasting for two weeks or longer, often accompanied by a loss of interest in life, hopelessness, and decreased energy. Like other medical disorders, clinical depression should not be ignored or dismissed. A clinically depressed person cannot simply "snap out of it" any more than a person with an ulcer could simply will it away.
Now if a candidate for the Presidency of the United States suffers from depression, I still think that she is capable decision maker. Being depressed doesn't mean having a character flaw or the sign of a weak personality. It means the person has a medical illness that is just as real as diabetes or ulcers. They can still make important decisions. If you tell the public, then people will doubt her ability to be president. Also, if you tell the public, then you must tell all the candidates health information to the public. This allows slippery slope to happen.
In conclusion, I wouldn't tell the public that the candidate for president has depression. It's their decision to tell the public, not mine.