Kevin can't get to sleep at night until he does many things. He straightens his chair and the books on his desk. He asks his mother questions he already knows the answers to. He checks under his bed for a light he knows isn't there, and then, a minute later, he checks again. Kevin knows these actions don't make sense; he wants to stop, but the worry thoughts keep coming. When his parents realize that Kevin has too many worries, they take him to talk to a therapist. She tells Kevin and his parents that Kevin has a condition called obsessive-compulsive disorder (OCD) and that, more importantly, he can be helped. One out of a hundred children suffer from OCD. Current research suggests that the condition is caused by a chemical imbalance in the brain.