Concussions and other childhood brain injuries are linked to a higher risk of later mental illness, poor school performance and even premature death, a new study reveals.
The study, published in PLOS Medicine, was lead by researchers from the UK, US and Sweden and funded by Wellcome, the world's largest medical research charity.
The research aimed to determine the long-term impact of having a traumatic brain injury before the age of 25 by analysing more than one million Swedes born between 1973 and 1985.
Professor Seena Fazel from Oxford University, lead author of the study, explained:
"Swedish data recording makes it possible to link anonymised health, welfare and education records. We looked at low educational attainment, instances of psychiatric care, receiving welfare and disability benefit and early death."
"We found that a childhood brain injury increased the chances of all these things. More serious brain injuries and repeated brain injuries made them even more likely."
77% of the head injuries recorded were considered to be mild head injuries or concussions whilst the remainder were more severe injuries.
Respondents who had experienced a brain injury were compared to their siblings and other uninjured people in the same age group.
"Comparing results within families allows for other factors in a person's upbringing that could have a bearing on their later life. The differences could still be seen between injured and uninjured siblings, indicating that the effect of head injury is independent of other factors, like upbringing," Prof. Fazel explains.
TABLE: Absolute risk (the resulting chance) of outcomes following childhood head injury in comparison to unaffected people in the same age group (University of Oxford).
People who had experienced a single mild, moderate or severe brain injury during childhood were at twice the risk of being admitted to hospital as a mental health inpatient (an increase in absolute risk from 5% to 10%), and were 50% more likely to use a mental health service (increase from 14% to 20%) than unaffected people in the same age group.
They were 80% more likely to receive disability benefits (increase from 4% to 6%) and 70% more likely to die before the age of 41 (increase from 0.8% to 1.6%). There were also 60% more likely to have done poorly at school (increase from 9% to 14%) or be in receipt of welfare benefits (increase from 12% to 19%).
People who had experienced repeated mild, moderate or severe brain injury were over two-and-a-half times more likely to receive disability benefits than contemporaries who had experienced a single-episode injury (increase from 6% to 12%).
While many of the results reinforce the growing body of research about the long term effects of head injuries in young people, this study is the largest undertaken so far. Professor Fazel continued:
'Our study indicates far-reaching and long-term consequences of head injury. It reinforces what we knew already - that prevention is key. As the data only included hospital admissions for head injury, and therefore didn't take into account less severe accidents many children have that go unrecorded, these are likely conservative estimates of the scale of the problem.
'Existing work to prevent head injuries to young people in sports, for example, needs to be enhanced. However, we cannot prevent every injury. Long term follow up could identify negative effects so that early intervention can prevent a drift into low attainment, unemployment and mental illness.'
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