More students from middle school to high school are misusing ADHD prescription drugs, amid an increasing number of children being diagnosed with the condition in the United States, a study published Tuesday finds. At some schools, as many as 1 in 4 students reported misusing drugs for attention-deficit/hyperactivity disorder in the previous year — meaning they used the medications without a doctor’s prescription or for nonmedical reasons, according to the study in JAMA Network Open.