NEW YORK (Reuters Health) - Children who go to school at an early age are 30 percent more likely to develop depression because they struggle to concentrate, understand lessons or make friends with older peers, according to a new research study at the London School of Health and Medicine.

Scientists analyzed records of more than a million children from all over the UK. The result was that younger students were 36 percent more likely to develop ADHD than older students. 30% susceptible to the diagnosis of "intellectual disability".

Scientists noted that children in the same school year are almost different in age, and found that the youngest of them may find it difficult to focus or understand the lesson or maintain friendships with older peers.

"We have known for a while that young children in the school year are more likely to develop hyperactivity disorders and tend to be academically less efficient than older children," said lead author Jeremy Brown. Relationship between younger relative age in school year and increased diagnosis of depression. "