Snoring is fairly common among school-age children, but it is more than twice as common among children with attention deficit-hyperactivity disorder (ADHD), according to information presented at the May 2001 meeting of the American Thoracic Society. This suggests a connection. Snoring can lead to decreased sleep quality, which can produce all of the symptoms of ADHD. When the snoring is treated, the ADHD often becomes much better or completely disappears, decreasing or eliminating the need for medicines. Exposure to passive tobacco smoke may indirectly lead to ADHD symptoms, because kids who are exposed to second-hand smoke have over a 100% - 300% increased chance of snoring.