CHICAGO (AP) - Almost one in five young American adults has a personality disorder that interferes with everyday life, and even more abuse alcohol or drugs, researchers reported Monday in the most extensive study of its kind. The disorders include problems such as obsessive or compulsive tendencies and anti-social behavior that can sometimes lead to violence. The study also found that fewer than 25 percent of college-aged Americans with mental problems get treatment. One expert said personality disorders may be overdiagnosed. But others said the results were not surprising since previous, less rigorous evidence has suggested mental problems are common...