It’s well established that a traumatic brain injury (TBI) can cause memory and cognitive problems, as well as depression, but now, researchers have looked at the consequences of repetitive head impacts.

They found that people exposed to repetitive head impacts may be more likely to experience difficulties with cognitive functioning and depression years later.

The researchers analysed data from the Brain health Registry on 13,000 adults, five per cent of whom reported having had repetitive head impacts through contact sports, abuse or military service.

They were asked about depressive symptoms and completed cognitive tests.

The paper, by researchers at Boston University and the University of California, San Francisco, reveals that participants who’d had repetitive head impacts and TBI reported greater depression symptoms than those who hadn’t.

Repetitive head injuries were a stronger predictor of depression than TBI, and those who had a history of repetitive head impacts and TBI with loss of consciousness reported the most depressive symptoms.

“The findings underscore that repetitive hits to the head, such as those from contact sport participation or physical abuse, might be associated with later-life symptoms of depression.

“It should be made clear that this association is likely to be dependent on the dose or duration of repetitive head impacts and this information was not available for this study,” said Michael Alosco, associate professor of neurology at BU School of Medicine (BUSM).

Those who’d experienced repetitive head impacts or TBI also performed worse in some of the cognitive tests.

“It should be noted that not all people with a history of repetitive hits to the head will develop later-life problems with cognitive functioning and depression,” says Study author Robert Stern, professor of neurology, neurosurgery and anatomy & neurobiology at BUSM.

“However, results from this study provide further evidence that exposure to repetitive head impacts, such as through the routine play of tackle football, plays an important role in the development in these later-life cognitive and emotional problems.”

The researchers point out, however, that one limitation of the research is that researchers didn’t have data on the extent of participants’ injuries.

Last year, BUSM researchers found that longer someone was exposed to tackle football, the higher the risk of developing the degenerative brain disease chronic traumatic encephalopathy.

For every year of exposure to the sport, footballers had a 30 per cent increased chance of having the disease.