They ask everyone else but the child what is the matter. And then they wonder why they are having these problems. I have never understood why parents keep vital information from their children. Well yes, maybe they will, but at least they will be informed of the dangers that sex and drugs can have on a person. And then again maybe they won't, because you sat down and explained to them what can actually happen if they do.
Children are smart.
They are much smarter than most parents tend to realize. They will listen to what you have to say, if you treat them as if they are people and not just your children. Don't make little remarks, and don't make accusations unless you have reason to do so. Take it from someone who knows. I grew up in a house where everything bad was not talked about.