Oppositional defiant disorder (ODD) develops only in children, but it can continue to affect them as they grow to become adults. Signs of ODD have usually appeared by the time a child reaches eight years of age. If a child much older than eight years shows symptoms of ODD, it is likely due to a different condition. Untreated ODD can cause children to develop additional behavioral problems as they grow into adolescents and adults. These include drug abuse, delinquency, and conduct disorder.