http://www.nytimes.com/2013/04/28/opinion/sunday/diagnosing-the-wrong-deficit.html

The patient didn’t have A.D.H.D., I realized, but a chronic sleep deficit. I suggested some techniques to help him fall asleep at night, like relaxing for 90 minutes before getting in bed at 10 p.m. If necessary, he could take a small amount of melatonin. When he returned to see me two weeks later, his symptoms were almost gone. I suggested he call if they recurred. I never heard from him again.

Many theories are thrown around to explain the rise in the diagnosis and treatment of A.D.H.D. in children and adults. According to the Centers for Disease Control and Prevention, 11 percent of school-age children have now received a diagnosis of the condition. I don’t doubt that many people do, in fact, have A.D.H.D.; I regularly diagnose and treat it in adults. But what if a substantial proportion of cases are really sleep disorders in disguise?

For some people — especially children — sleep deprivation does not necessarily cause lethargy; instead they become hyperactive and unfocused. Researchers and reporters are increasingly seeing connections between dysfunctional sleep and what looks like A.D.H.D., but those links are taking a long time to be understood by parents and doctors.