A possible connection between Attention Deficit/Hyperactivity Disorder (ADHD) and a genetic malfunction in the thalamus may explain the distractibility and physical restlessness that plague children and adults with ADHD, a group of New York University, MIT and Duke University scientists have reported.The genetic defect they’ve detected may be particularly relevant to the approximately 30 percent of the ADHD cases that are not responsive to treatment with stimulants, their study said.