Teen parenting expert Rosalind Wiseman on how to determine whether your kid's pal is drinking or getting high before she comes to your house.

By Rosalind Wiseman

Q. My daughter's best friend sleeps over a lot and lately I've been wondering whether she's drunk or high. Both girls are 16. What should I do?

A. Whenever you have a gut feeling about a teen's behavior, trust it. Ask the girls if either one has been drinking or using drugs (yes, I'm including your daughter). Then tell them exactly why your "something isn't right here" alarm bells are going off. If you get a confession, thank them for being honest but state clearly that the behavior is against house rules. Your daughter will get the punishment you give her and the friend has to call her parents to say they must pick her up and why. Also, tell her she's welcome to return to your home provided that she's sober. If she denies using anything, explain that you still have to share your concerns with her parents. Just remember, your goal is to respond in an empathetic yet firm way.

Originally published in the July 2008 issue of Family Circle magazine.