There is new evidence that brief pauses in breathing (apnea) during infancy may be a cause of ADHD. Dr. Glenda Keating of Emory University presented data at the Society for Neuroscience annual meeting in October 2004, showing that repetitive drops in blood oxygen levels in newborn rats similar to that caused by apnea in some human infants is followed by a long-lasting reduction in dopamine levels, associated with ADHD. Apnea occurs in up to 85% of prematurely born human infants. ScienceDaily