Is Alleged 'Craigslist Killer' Miranda Barbour a Serial Murderer?

Twenty-one-year-old Melissa suffers from obsessive-compulsive disorder and says most of her rituals are focused on one thing — trying to make herself more attractive than her older sister, Justine. Melissa says she constantly chants, “I want to be prettier than Justine,” in her head, making it difficult for her to even hold a normal conversation. She says she must also perform numerous rituals throughout the day, which she believes will make her prettier — and Justine uglier. She admits that her behavior is disruptive to her life — and has hurt her relationship with her sister — but says she can’t control it. Melissa’s mother, Noreen, says she’s also at a loss for how to help her daughter, and she hates to see her daughters in conflict. What does Dr. Phil think is at the root of Melissa’s obsession? Then, Dr. Phil has a big challenge for Melissa, who is adamant that she does not want to be onstage with Justine, out of fear that people will compare them. Will she agree to let her sister join the conversation? How can Melissa learn to manage her OCD — and reclaim her life?