 Substance use as well as emergency room visits due to mental health issues. The eyes of the world and the country will be on President Biden Thursday when he holds a solo press conference. CBS's Ed O'Keefe has that. The stakes are incredibly high. This is something Washington will be watching closely. Voters concerned about the president's ability is also watching because it's yet another big unscripted moment where he's going to be taking questions, having to think on his feet.