Knowing Gabe has befriended a sketchy guy makes me afraid my son will fall completely under the friend's influence, make bad choices, and lose sight of his own goals. It's tough but I'm trying to keep my dread in perspective. "Hanging out with a rebellious or troubled kid isn't a guaranteed problem," says Lisa Boesky, PhD, author of When to Worry: How to Tell If Your Teen Needs Help and What to Do About It (Amacom). "It's only worrisome if your kid becomes the troubled teen. Although teens may flirt with brief lapses in judgment -- and who doesn't? -- they aren't going to automatically drop everything you've ever taught them."