A new study found how those suffering from traumatic brain injury are more likely to die early than the general population, either from a fatal injury or from suicide.
The findings in the Journal of the American Medical Association (JAMA) Psychiatry suggest a need for longer term care and follow-up of the millions of people who suffer these injuries each year.
Traumatic brain injury (TBI) can be caused by a blow to the head that results in skull fracture, internal bleeding, loss of consciousness for over an hour or a combination of these, said the report.
The recent skiing accident that left German Formula One champion Michael Schumacher in a coma is an example of TBI.
Researchers at Oxford University and the Karolinska Institute in Stockholm analyzed data on traumatic brain injuries in Sweden among people born in 1954 or later.
They compared medical records from more than 218,000 TBI survivors to 150,000 siblings of TBI survivors as well as two million control cases.
"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," said study leader Seena Fazel, a Wellcome Trust Senior Research Fellow in Oxford University's Department of Psychiatry.
Premature death was defined as dying before the age of 56.
The main causes of premature death in TBI survivors were suicide and fatal injuries such as car accidents and falls.
"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," said Fazel.
Since current medical guidelines do not call on doctors to assess mental health or suicide risk in TBI patients, the findings suggest a longer term approach to care.
"TBI survivors should be monitored carefully for signs of depression, substance abuse and other psychiatric disorders, which are all treatable conditions," said Fazel.
The reasons for the increased risk of early death were unclear, but Fazel said it might have to do with impaired judgment.
Concussions, a milder injury frequently sustained among athletes, were studied separately but were also found to increase the risk of early death twofold, with suicide and fatal injuries the main causes of death.
From 2012 to 2013, there were almost 200,000 head injuries requiring hospital visits in Britain, of which nearly 126,000 led to TBIs, according to the article.
Some 1.7 million people in the United States and one million people in Europe are hospitalized after TBIs each year.
The most common causes are auto accidents, falls and sporting injuries.