New research links participation in team sports to larger hippocampal volumes in kids and less depression in boys ages 9 to 11.
Adult depression has long been associated with shrinkage of the hippocampus, a brain region that plays an important role in memory and response to stress.
“Our findings are important because they help illuminate the relationships between involvement in sports, volume of a particular brain region and depressive symptoms in kids as young as nine,” says Lisa Gorham, lead author of the study and a senior majoring in cognitive neuroscience at Washington University in St. Louis.
“We found that involvement in sports, but not non-sport activities such as music or art, is related to greater hippocampal volume in both boys and girls, and is related to reduced depression in boys,” Gorham says.
These relationships were particularly strong for children participating in sports that involved structure, such as a school team, a non-school league, or regular lessons, as compared to more informal engagement in sports, according to the study, which appears in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging.
The findings raise the intriguing possibility that there is some added benefit of the team or structured component of sports, such as the social interaction or the regularity that these activities provide, says senior study author Deanna Barch, chair of the psychological and brain sciences department in the School of Arts & Sciences and professor of psychiatry at the Washington University School of Medicine in St. Louis.
Researchers based the study on a nationwide sample of 4,191 children ages 9-11 years from the Adolescent Brain and Cognitive Development Study. Parents provided information on their child’s participation in sports and other activities and on depressive symptoms. Brain scans of the children provided data on their bilateral hippocampal volume.
While other studies have shown the positive impact of exercise on depression and the link with hippocampal volume in adults, this study is among the first to show that participation in team sports may have similar antidepressant effects in preteen children.
The results indicate that there was an association between sports involvement and hippocampal volume in girls, but unlike boys, no additional association with depression. This might mean that different factors contribute to depression in girls, or that a stronger association to sports involvement might emerge at a later developmental period for girls.
Cause and effect?
It’s important to note, Barch and Gorham write, that these results are correlational, not causational. It could be that participating in sports leads to increased hippocampal volume and decreased depression, or it could be that children who are more depressed are less likely to engage in sports and also have smaller hippocampal volume. Either scenario could have important implications for understanding childhood depression.
“The fact that these relationships were strongest for team or structured sports suggests that there might be something about the combination of exercise and the social support or structure that comes from being on a team that can be useful at preventing or treating depression in young people,” Gorham says. “The findings raise intriguing possibilities for new work on preventing and treating depression in children. ”
Confirming the impact of team sports on brain development and mood would provide strong support for encouraging children to participate in structured sports that provide both exercise and social interaction.
“These interesting results provide important clues as to how exercise benefits mood in children and reveals the important role that gender plays in these effects,” says Cameron Carter, editor of Biological Psychiatry: Cognitive Neuroscience and Neuroimaging and a professor of psychiatry and psychology at the University of California, Davis.
Additional coauthors came from the University of California, San Diego and the University of Vermont.