Every night, in comedy clubs across the country, comics bare their souls onstage. They dig deep within themselves to make people laugh, to distract them from their troubles and, for at least a few minutes, take away their pain. But sometimes it's the comedian who is in pain themselves, and all the laughter and applause in the world isn't enough to make them feel better. To battle the sinister force that is depression is no laughing matter. For comedian Gary Gulman, that struggle is very real, but with his new HBO special The Great Depresh, he gets the …