we need to keep eyes on it.
food, environment, People's mind as technic develops, accelated life time, etc
all makes above tendency.
 



http://edition.cnn.com/2011/HEALTH/05/23/autism.adhd.increase.cdc/index.html?eref=rss_health&utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2Fcnn_health+%28RSS%3A+Health%29 
AND