“It’s astounding to me how parents decide that they want to be a friend to their child because the child resists authority,” Dr. Phil says. He reminds parents, “The most powerful role model in any child’s life is the same-sex parent.”

TELL DR. PHIL YOUR STORY: Need help fixing a broken relationship?

On Friday’s episode, Dr. Phil speaks with Melinda and her 18-year-old daughter, Cassidy, who claims her mom has partied with her and been more like a friend than a parent. When Melinda states that she has taken the friend role with her daughter because Cassidy likes her better that way, Dr. Phil tells her she is blurring boundaries and it’s time she learn how to re-parent the teen.

WATCH: Woman Says She Fears Daughter May Kill Her; Teen Says Mom Is An 'Attention Seeker'

Hear more of Dr. Phil’s advice in the video above. And watch Melinda and Cassidy’s story on Friday’s episode. Check here to see where you can tune in.

TELL DR. PHIL YOUR STORY: Do you need Dr. Phil to "get real" with someone?



'I’ve Always Been Put Down To The Lowest By Everyone But Mostly By My Mom,' Teen Says