Walk into any office, school, or public building, and somewhere on its wall you'll find a physical first aid kit. Fire drills happen periodically in schools and colleges. Some people at your workplace know CPR. Decades of effort have gone into making sure people know how to respond when someone is dealing with a physical injury. Now, picture a different kind of emergency. A colleague who used to pitch three ideas in every meeting has gone quiet for weeks, and nobody's said anything. A student...