Adolescents who play contact sports, including American football, are no more likely to experience cognitive impairment, depression or suicidal thoughts in early adulthood than their peers, suggests a University of Colorado Boulder study of nearly 11,000 youth followed for 14 years.
The study also found that those who play sports are less likely to suffer from mental health issues by their late 20s to early 30s. "There is a common perception that there's a direct causal link between youth contact sports, head injuries and downstream adverse effects like impaired cognitive ability and mental health," said lead author Dr Adam Bohr, a post-doctoral researcher in the department of integrative physiology. "We did not find that."
The study comes on the heels of several highly-publicised papers linking sport-related concussion among former professional football players to chronic traumatic encephalopathy (CTE), cognitive decline and mental health issues later in life. Such reports have led many to question the safety of youth tackle football, and participation is declining nationally.
But few studies have looked specifically at adolescent participation in contact sports. "When people talk about NFL players, they are talking about an elite subset of the population," said senior author Matthew McQueen, an associate professor of integrative physiology. "We wanted to look specifically at kids and determine if there are true harms that are showing up early in adulthood."
The study analysed data from 10,951 participants in the National Longitudinal Study of Adolescent to Adult Health (Add Health), a representative sample of youth in seventh through 12th grades who have been interviewed and tested repeatedly since 1994. Participants were categorised into groups: those who, in 1994, said they intended to participate in contact sports; those who intended to play non-contact sports; and those who did not intend to play sports. Among males, 26% said they intended to play football.
After controlling for socioeconomic status, education, race and other factors, the researchers analysed scores through 2008 on word and number recall and questionnaires asking whether participants had been diagnosed with depression or attempted or thought about suicide.
"We were unable to find any meaningful difference between individuals who participated in contact sports and those who participated in non-contact sports. Across the board, across all measures, they looked more or less the same later in life," said Bohr.
Football players – or reasons that are not clear – actually had a lower incidence of depression in early adulthood than other groups. Those who reported they did not intend to participate in sports at age 8 to 14 were 22% more likely to suffer depression in their late 20s and 30s. "Right now, football is in many ways being compared to cigarette smoking – no benefit and all harm," said McQueen, who is also director for the Pac-12 Concussion Coordinating Unit. "It is absolutely true that there is a subset of NFL players who have experienced horrible neurological decline, and we need to continue to research to improve our understanding of that important issue."
But, he said, "the idea that playing football in high school will lead to similar outcomes later in life as those who played in the NFL is not consistent with the evidence. In fact, we and others have found there is some benefit to playing youth sports."
A recent University of Pennsylvania study of 3,000 men who had graduated high school in Wisconsin in 1957 found that those who played football were no more likely to suffer depression or cognitive impairment later. But some pointed out that the sport had changed radically since the 1950s.
The study is among the largest to date and looks at those who played football in the 1990s. The authors note that, due to the design of the dataset, they were only able to measure "intended" participation. (Due to the timing of the questionnaires, however, it is likely that those who reported participation in football actually did participate.)
They also could not tell how long an adolescent played, what position or whether a concussion or sub-concussive head injury was ever sustained. Further studies should be done exploring those factors, they said.
"Few current public health issues are as contentious and controversial as the safety and consequences of participation in football," they concluded. "Research on the risks of participation weighed with the risks of not participating in sports will enable parents and young athletes to make educated, informed decisions based on solid evidence."
A new CU Boulder study, looking at the long-term mental and physical health of CU student-athlete alumni, is already underway.
Background: Recent studies have associated sport-related concussion with depression and impaired cognitive ability later in life in former professional football players. However, population studies with two 1950s-era cohorts did not find an association between high school football participation and impaired cognition or depressive symptoms in late adulthood.
Purpose/Hypothesis: This study assessed whether actual/intended participation in contact sports during adolescence had an adverse effect on participants’ cognition or depressive symptoms in early adulthood. We hypothesized that there would not be an association.
Study Design: Cohort study; Level of evidence, 2.
Methods: This study used a subsample (n = 10,951) from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a nationally (United States) representative prospective cohort study following participants through 4 waves of data collection from 1994 through 2008. Participants were categorized as actual/intended participation in no sports, noncontact sports only, and contact sports. We constructed 6 multivariate and logistic regression models predicting word recall, number recall, modified Center for Epidemiologic Studies Depression Scale, depression diagnosis, suicide ideation, and suicide attempts at wave IV as a function of sport participation during wave I. Sport participation was treated as a factor with the referent category noncontact sports. This analysis was repeated on a males-only sample (n = 5008). In the males-only analysis, participants were classified as actual/intended participation in no sports, noncontact sports, contact sports other than American football, and American football. The referent category remained noncontact sports.
Results: Intention to participate in contact sports was not significantly associated with any of the outcomes in the full-sample analysis. Intention to participate in football was significantly associated with a reduced odds of depression diagnosis in adulthood (odds ratio, 0.70; P = .02) when compared with noncontact sports participation in the males-only sample. Football was not significantly associated with impaired cognitive ability, increased depressive symptoms, or increased suicide ideation.
Conclusion: Actual/intended participation in contact sports during adolescence did not adversely affect Add Health participants’ cognition or depressive symptoms in young adulthood.
Adam D Bohr, Jason D Boardman, Matthew B McQueen
[link url="https://www.colorado.edu/today/2019/10/18/study-finds-no-link-between-youth-contact-sports-and-cognitive-mental-health-problems"]University of Colorado Bolder material[/link]
[link url="https://journals.sagepub.com/doi/10.1177/2325967119868658"]Orthopaedic Journal of Sports Medicine abstract[/link]