Concussion and depressive symptoms in high school students: impact of physical activity and substance use

To investigate the association between concussion history and depressive symptoms after adjusting for physical activity, substance use, and illicit drug use.

We analysed data from the Adolescent Behaviour and Experiences Survey, a nationally representative survey of adolescents in the USA. Our independent variables were history of concussion in the 12 months preceding survey completion; self-reported weekly physical activity (days per week with >60 min of physical activity, 0-7 scale); substance use over the past 30 days (yes vs no) and illicit drug use throughout lifetime (yes vs no). Our dependent variable was participant-reported sadness/hopelessness over the past 12 months (yes vs no).

Among 7499 adolescents (9th-12th grade, 50.4% female), reporting one or more concussions over the past year was not associated with the odds of depressive symptoms (OR: 1.13, 95% CI: 0.93 to 1.37, p=0.21). Each additional day of physical activity per week was associated with a lower odds of depressive symptoms (OR: 0.91; 95% CI: 0.89 to 0.94; p<0.0001). Illicit drug use (OR ever vs never: 2.48; 95% CI: 1.96 to 3.13; p<0.0001) and substance use (OR yes vs no: 2.77; 95% CI: 2.34 to 3.29; p<0.001) were associated with a higher odds of depressive symptoms.

Adjusting for physical activity, substance use and illicit drug use, concussion was not significantly associated with depressive symptoms. This novel discovery informs clinicians as they counsel adolescents with concussion; future research should examine physical activity and avoidance of substance/illicit drug use as postinjury recommendations in an effort to lower the risk of depressive symptoms.