5 Takeaways From New Research About A.D.H.D.

As diagnoses of A.D.H.D.and prescriptions for medications hit new record highs, scientists who study the condition are wrestling with some fundamental questions about the way we define and treat it.

More than 15 percent of American adolescents have been diagnosed with A.D.H.D., according to the Centers for Disease Control and Prevention, including 23 percent of 17-year-old boys.A total of seven million American children have received a diagnosis.Normally, when a diagnosis booms like this, it’s because of some novel scientific breakthrough — a newly discovered treatment or a fresh understanding of what causes the underlying symptoms.

I spent the last year interviewing A.D.H.D.scientists around the world for my magazine article, and what I heard from them was, in fact, the opposite: In many ways, we now understand A.D.H.D.

less well than we thought we did a couple of decades ago.Recent studies have shaken some of the field’s previous assumptions about A.D.H.D.

At the same time, scientists have made important discoveries, including some that are leading to a new understanding of the role of a child’s environment in the progression of his symptoms.At a moment of national concern about our shrinking attention spans, this science suggests that there may be some new and more effective ways to help the millions of young people who are struggling to focus.Below are the key findings from the new research.A.D.H.D.is hard to define — and recent science has made it harder, not easier.A.D.H.D.

has always been a tricky condition to diagnose.One patient’s behavior may look quite different from another’s, and certain A.D.H.D.

symptoms can also be signs of other problems, from anxiety and depression to childhood trauma and autism spectrum disorder.Twenty years ago, researchers thought they were on the verge of ending that controversy by finding a distinct “biomarker” for A.D.H.D.

— a single gene that would reliably predict the disorder, or a physical diffe...