To be diagnosed with oppositional defiant disorder, a child must meet criteria spelled out in the Diagnostic and Statistical Manual of Mental Disorders (DSM).

CNN: Oppositional defiant disorder (ODD)

Now, the first study of its kind has found that most are psychologically healthy, though they're at "slightly increased risk" for behavioral problems such as attention deficit hyperactivity disorder or oppositional defiant disorder.

NPR: Adopted Teens Face Higher Risk for ADHD