Concussion in 20s could increase dementia risk by 60%
Suffering concussion or other brain injuries in your 20s could increase the risk of dementia by more than 60 percent, a major study suggested.
The research on almost three million adults, published in the Lancet Psychiatry, follows increasing debate about the longterm consequences of blows to the head suffered in football and boxing, according to telegraph.co.uk.
The new study by the Washington School of Medicine tracked adults for almost four decades.
Overall, those who suffered a traumatic brain injury — including concussion — during their lifetime saw the risk of dementia increase by 24 percent.
Even a relatively minor knock on the head resulting in concussion led to a 17 percent risk increase, researchers found.
In absolute terms, 5.3 percent of participants with dementia had a history of such injuries compared with 4.7 percent of those who did not.
The impact was greatest among those who suffered such injury in their 20s, who were 63 percent more likely to develop dementia than those without such a history, the study found.
Experts said that the study was one of the first to have sufficient sample size and followup time to assess the effect of TBI in younger adults on longterm dementia risk.
Lead author Prof. Jesse Fann, said, “Individuals with a history of traumatic brain injury, including those with less severe injuries have an increased risk of developing dementia, even decades after the injury”.
The professor of psychiatry and behavioral sciences at the University of Washington School of Medicine, in Seattle, stressed that absolute risks remained low.
He said, “Our findings do not suggest that everyone who suffers a traumatic brain injury will go on to develop dementia in later life.”
The scientists identified every diagnosis of TBI from the health records of a Danish population of 2.8 million people between 1977 and 2013.
Over 36 years, 132,093 individuals had at least one TBI, and most cases were categorized as mild.
Between 1999 and 2013, 4.5 percent of the study population aged 50 and older were diagnosed with dementia.
Researchers highlighted other studies, which have suggested a higher risk of dementia
Dr. Ben Lennox Kail, first author of the study and assistant professor of sociology at Georgia State, said, “We looked at the interrelationships between marriage, income and depression, and what we found is that the benefit of marriage on depression is really for people with average or lower levels of income.
“Specifically, people who are married and earning less than $60,000 a year in total household income experience fewer symptoms of depression. But above that, marriage is not associated with the same kind of reduction in symptoms of depression.”
This study, among only a few to investigate whether psychological well-being in marriage varies by socioeconomic status, supports a theory called the marital resource model, which suggests the health benefits of marriage include the pooling of resources, such as finances and social support.
Kail said, “For people who are earning above $60,000, they don’t get this bump because they already have enough resources.
“About 50 percent of the benefit these households earning less than $60,000 per year get from marriage is an increased sense of financial security and self-efficacy, which is probably from the pooling of resources.
“Also, it’s interesting to note, at the highest levels of income, the never married fare better in terms of depression than the married. They have fewer symptoms of depression than married people.
“All of these are subclinical levels of depression, meaning the disease is not severe enough to be clinically referred to as depression, but can nevertheless impact your health and happiness.” among participants of contact sports such as boxing and football, as well as among soldiers.
The Telegraph launched a campaign in 2016 for research into the prevalence of dementia among former footballers.
The new study identified a cumulative effect from repeated blows, with dementia risk rising with repeated episodes of brain injury.
The risk was increased nearly three-fold for people who had suffered five or more traumatic brain injuries.
The Football Association has commissioned independent research examining the risks of dementia among former footballers, following a campaign by the family of Jeff Astle, a former England striker, who died from Chronic Traumatic Encephalopathy, a disease caused by blows to the head, with symptoms like those of dementia.
Dr. Carol Routledge, director of research at Alzheimer’s Research UK, said, “This well-conducted study adds significant weight to previous evidence of a link between head injury and an increased risk of dementia.
“While there is growing interest in the question of whether collisions in sports like rugby or football might affect dementia risk, this study only looked at head injuries that required hospital treatment and doesn’t tell us anything about the impacts you’d normally expect to see on the sports field.
Prof. Jonathan Schott, professor of neurology, University College London (UCL), said, “This population based study of over 2.5 million people provides perhaps the best evidence yet that traumatic brain injury is a risk factor for dementia.
“Whilst the study shows that the number, severity, and timing of head injuries influences risk, further research is required to establish the extent to which specific types of head injury (e.g. sports concussions) are or are not implicated.”