The results of the study, which included 62,000 children, show head and burn injuries before two years of age may double the risk of ADHD diagnosis by 10 year of age.

The study suggests that usually injuries are an early sign of ADHD behavior. Some experts say that the study may help GPs to find children who need specialist referral.

Another previous study has already suggested that mild brain injury has links with behavioral changes in children.

Though there is a link between ADHD and head injury, it’s not clear which comes first, the researchers say.

In this current study, researchers from UK and US say that they have found higher rates of ADHD diagnosis in children who were treated for a head injury at younger age.

The researchers used data from more than 300 general practices from 1988 to 2003 and they noticed that these two types of injuries were related to greater rates of ADHD diagnosis than children without such injuries.

The study also discovered that those children who had a head injury after the age of two had higher chances of being diagnosed with ADHD before their 10th birthday.

In the study, parents of 1 to 5 year old children, who were breastfed as infants were 15 percent less likely to report concern for the child’s behavior than those parents, who were not breastfed.

In addition, breastfed children have 37 percent less chances to have doctor-diagnosed behavior or mental disorders or to have received mental health care.

The results based on more than 100,000 interviews with parents or guardians on the health of their children conducted as part of the 2003 National Survey of Children’s Health — also push studies that have showed breastfeeding enhances intellectual ability in children.

Specially, parents of breastfed children were 23 percent less apt to report concern about their child’s learning ability, according to study lead researcher Dr. Katherine Hobbs Knutson from Massachusetts General Hospital, Boston.

“Although correlations between breastfeeding and childhood cognition are well supported by research, our findings provide new evidence for a lesser understood issue of whether breastfeeding may also influence childhood emotional development,” Knutson said.

“Our research is promising, indicating that human milk may be protective against childhood behavioral disorders,” she concluded.