Weird urges hound people with obsessive-compulsive disorder.
But researchers are learning more all the time about the causes, and treatments. Driving down the New Jersey Turnpike, Susan Duffy heard a low thump and felt the car's tires bounce over something. Though she had seen nothing in the road, Duffy frantically wondered if she'd hit a pedestrian. So she retraced her route, looking for a body. Still not convinced, she exited and drove the route again.