Back from Iraq, Army Sgt. Kristofer Goldsmith remembers choking someone into unconsciousness at a party for no reason. "That's not who I was before I deployed," he says. His breaking point came when his unit was ordered to stay beyond their volunteer commitments. "I took my half bottle of Percocet and ... drank until I couldn't drink anymore." He survived and now lives with his parents. He's among the nearly 20 percent of returning U.S. veterans who suffer from post traumatic stress disorder or major depression