Attention deficit disorder: Old questions, new answers

Despite persistent skepticism, the most common childhood psychiatric disorder is increasingly understood to be a brain malfunction. Different forms of the disorder may have different biological roots. New versions of older drugs are being introduced, and new drugs are being considered. Old and new concerns about the risks of drugs are raised, and there is now some evidence for alternative treatments. National, regional, and racial disparities in diagnosis and treatment persist and raise difficult questions.

Discoveries in neuroscience are reinforcing a growing consensus that attention-deficit/hyperactivity disorder (ADHD), as it is officially known, is not just a set of behavior problems but a biologically based disorder of brain function. The symptoms of impulsiveness, inattentiveness, and hyperactivity arise, this research suggests, because misfiring of the brain's executive function — its management system — make it difficult to stay still, concentrate, and exercise forethought and self-control.