For decades, Attention-Deficit/Hyperactivity Disorder (ADHD) has been all about behavior: kids who couldn’t sit still, adults who daydream, or anyone who acts ...

The classic image of a child with ADHD is practically a stock character: the spacey kid staring out the window, distracted by squirrels; the fidgeter who can't sit still, a leg rattling under the desk ...

Decades of ADHD brain imaging studies have produced maddeningly inconsistent results, and researchers have been blaming methodology — but a new study suggests the real problem was assuming ADHD is one ...

Previous attempts to define subtypes using symptom checklists have usually ended up grouping people mainly by how severe their symptoms are. To move beyond this limitation, the researchers in this ...