New research suggests traumatic brain injury survivors are three times more likely to die prematurely from "suicide or fatal injury" than the general population.

TBIs are blows to the head that result in a skull fracture, internal bleeding, loss of consciousness that lasts for over an hour, or combination of these symptoms, a University of Oxford news release reported.

A research team looked at 41 years' worth of data from "218,300 TBI survivors, 150,513 siblings of TBI survivors and over two million control cases matched by sex and age from the general population," the news release reported.

"We found that people who survive six months after TBI remain three times more likely to die prematurely than the control population and 2.6 times more likely to die than unaffected siblings," study leader Doctor Seena Fazel, a Wellcome Trust Senior Research Fellow in Oxford University's Department of Psychiatry said in the news release. "Looking at siblings who did not suffer TBIs allows us to control for genetic factors and early upbringing, so it is striking to see that the effect remains strong even after controlling for these."

The team found the highest risk of early death was in TBI survivors who had a history of psychiatric disorders or substance abuse. Premature death was classified as passing away before the age of 56. These TBI victims are three times more likely to die from fatal injuries.

"TBI survivors are more than twice as likely to kill themselves as unaffected siblings, many of whom were diagnosed with psychiatric disorders after their TBI," Fazel said. "Current guidelines do not recommend assessments of mental health or suicide risk in TBI patients, instead focusing on short-term survival. Looking at these findings, it may make more sense to treat some TBI patients as suffering from a chronic problem requiring longer term management just like epilepsy or diabetes. TBI survivors should be monitored carefully for signs of depression, substance abuse and other psychiatric disorders, which are all treatable conditions."

The reason for this higher rate of early death is yet to be confirmed, but it could be linked to damage in regions of the brain responsible for regulating "judgment, decision-making and risk taking," the news release reported.

"This study highlights the important and as-yet unanswered question of why TBI survivors are more likely to die young, but it may be that serious brain trauma has lasting effects on people's [judgment]," Fazel said. "People who have survived the acute effects of TBI should be more informed about these risks and how to reduce their impact."

"When treating traumatic brain injuries focus is placed on immediate treatment and recovery of patients," Doctor John Williams, Head of Neuroscience and Mental Health at the Wellcome Trust, said. "This new finding offers important insight into the longer-term impact of TBI's on the brain and their effect on survival later in life. We hope that further research into understanding which parts of the brain are responsible will help improve future management programmes and reduce the potential for premature death."

Even individuals who had only suffered a concussion were twice as likely to die prematurely.