Now, let's go to David. You have a special report coming out tonight. For some time now, we've been following children, who have been crippled by fear of their own anxiety. The parents, seemingly... See More
Now, let's go to David. You have a special report coming out tonight. For some time now, we've been following children, who have been crippled by fear of their own anxiety. The parents, seemingly hopeless, wondering, will our children ever break free? But they and we never gave up on those children. 15-year-old Bridget looks like your typical teenager on the outside. But inside, she is wrestling to break free from unimaginable fear. On this day, her progress is measured in inches. What do you think? Like nine. Reporter: The woman at the other end of the sofa, is about to move from her chair to the couch. Tell me what's going on? She got so close. And she's never been this close before. Reporter: That woman who has Bridget so terrified is her own mother. Bridget has been diagnosed with obsessive compulsive disorder. Her particular obsession, an irrational fear that her own family is contaminated. Long before the worries, Bridget was a beautiful little girl. A standout swimmer in the pool. Fish in the water. And Bridget is hardly alone in her fight against fear. Her fight against anxiety. It E it's estimated 9 million children are diagnosed. I don't remember. Get the phone. Reporter: Rocco's obsession revolves around the fear of getting sick. The fear of what would happen when he leaves for school. You remember what I said. I don't know what I said. Why do you do that? Reporter: We have followed Rocco for five years now, who watched as his parents got him out of the house, on to this carousel. At the time, distracting him. We talked about his little league. 17-1-1. Reporter: The biggest victory was just getting him here. Even for rocrocco, thinking about it all, was painful. Five years later, new science. In a groundbreaking study of children who have OCD, they can see it. If a child has OCD, you can see something in the brain. The key is that the light switch of the brain isn't working properly. That causes the whole system to go haywire. Reporter: And we go back to the children, Bridget and Rocco among them. And what we find will give incredible hope to any parent who has ever had an anxious child. Hey, rock Ke. David, how have you been? Reporter: You, too. You were about this tall. It's really something. Four children and their parents. We've stood by their side. It's going to give you hope if you had a nervous child. You can see the special. "20/20," the children who breakaway from fear. Let's go to central park. Lara and ginger with great
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