For the study, the researchers reviewed electronic health care records from more than 1 million school children in the United Kingdom. The investigators found that children born in the last quarter of a school year were 36% more likely than kids born in the first quarter of a school year to be diagnosed with ADHD. The youngest kids were 30% more likely to have an intellectual disability and 31% more likely to have depression than their older classmates...The study was published online Sept. 23 in JAMA Pediatrics.