Child brain injury and ADHD

Very young children who injure themselves are more likely to be diagnosed with hyperactivity disorder later, according to new research.

The research also suggests that head injury is not a cause of ADHD but that, like other injuries, it may be an early sign of the condition.

The researchers say that children with ADHD take more risks when they are very young and are therefore more likely to experience injuries. However, parents of accident-prone toddlers shouldn't get too anxious. Accidents and injuries are common in early childhood but they don't mean a child has ADHD.

Children with ADHD find it hard to concentrate or sit still, and often act without thinking. Although all children are like this at times, children with ADHD behave this way most of the time, both at home and in other places, like school. This can be hard on their families and teachers.

We don't know what causes ADHD. There may be several things that act together to make it more likely. Possible risk factors include genes, smoking in pregnancy and head injury.

We know that head injuries are more common in children with ADHD but it isn't clear why this is the case. Some studies have found that a bad head injury that results in damage to the brain can cause this condition. It's also possible that having ADHD makes it more likely that a child gets injured.

Researchers tried to find out more about whether head injury is a cause of ADHD or whether children with this condition are generally more likely to sustain injuries at an early age. They looked at the medical records of children who'd had a head injury, children who'd had a burn or scald, and children who'd had neither type of injury. They thought that if head injury caused ADHD, more children in this group would be diagnosed with the disorder than in the other two groups.

The researchers found that children who needed treating for a head injury and children who needed treating for a burn or scald were equally likely to be diagnosed with ADHD by the age of 10. These children had about double the chance of being diagnosed with ADHD compared with children who'd had neither of these types of injury.

The results suggest that ADHD is not caused by head injury. Burns and scalds wouldn't cause ADHD, and children with burns had the same risk of ADHD as children with head injuries. The researchers suggest that children who are later diagnosed with ADHD are more impulsive and active when they are toddlers. So injuries at a young age could be an early warning sign that they might go on to be diagnosed with ADHD.

But, even so, most children who had injuries didn't go on to get ADHD.

About 3 in 100 children with head injuries or burns got ADHDBetween 1 and 2 in 100 children who had neither injury got ADHD.Where does the study come from?
The study looked at medical records of children enrolled in a large health improvement study, from 308 general practices in the UK. The records were analysed by researchers from the University of Utah and the University of North Carolina, in the United States. The study was published online by the British Medical Journal (BMJ), which is owned by the British Medical Association.

The study was done using medical records of more than 62,000 children. So it's a big study and likely to be accurate. However, there are some things missing from the medical records that make it slightly less reliable. Most importantly, we don't know how serious the head injuries were. We know the children needed treatment from a doctor, so they weren't just grazes or scrapes, but we don't know whether they were serious enough to cause brain damage.

This is important because some previous studies have shown that severe head injuries do lead to problems with a child's behaviour, including ADHD. The results might have been different if the study had looked at children with serious injuries and children with less serious injuries separately.

Source - BMJ