Experience at other democratic free schools indicates that this is not a problem. They find that when children are allowed to expend their excess energy through play, they can then focus. According to John Holt in Learning All the Time, research by specialists in learning disabilities links so-called "perceptual handicaps" with stress. Such research has shown that when students with supposedly severe learning disabilities were placed in a relatively stress-free situation, their disabilities soon vanished. Millions of children in the United States are on prescription medication, sometimes called the "school drug", to control their behavior and promote learning. Other democratic free schools have found that there is no longer a perceived need for these drugs when children are not coerced into learning, and when the need to be responsible for their behavior comes from within. The democratic process in particular promotes development of this internalized sense of responsibility for one's own behavior through honest, direct interaction with a community of friends and peers.