Background There has been increased attention on the long-term effects of concussion. The objective was to examine youth who have or have not sustained a concussion to determine the risk of adverse psychosocial outcomes.

Methods A retrospective population-based analysis was conducted among Manitoba youth (10–18 years) between 2000–2005. Using provincial administrative health data, concussion cases were identified and matched by age and neighborhood to randomly selected non-concussion controls. Youth were followed for 10–15 years. New onset psychiatric, social, and judicial outcomes were extracted using linked administrative datasets. Adjusted hazard ratios with 95% confidence intervals were calculated.

Results There were 2082 concussed youth matched to 10,510 non-concussed youth. Concussed youth had an increased risk of any psychiatric disorder (HR: 1.34; 95% CI: 1.25, 1.45), mood disorder (HR: 1.30; 95% CI: 1.18, 1.43), psychosis (HR: 1.43; 95% CI: 1.18, 1.74), substance abuse disorder (HR: 1.67; 95% CI: 1.31, 2.14), and receiving a psychotropic prescription (HR: 1.31; 95% CI: 1.20, 1.42). Girls had an increased risk of ADHD following concussion (HR: 1.89; 95% CI: 1.17, 3.05). Concussed youth had an increased risk of being accused (HR: 1.22; 95% CI: 1.11, 1.34), victim (HR: 1.29; 95% CI: 1.11, 1.48), or witness (HR: 1.16; 95% CI: 1.01, 1.32) of a crime or having contact with Child and Family Services (HR: 1.33; 95% CI: 1.10, 1.62). There was no association between concussion and risk of attempting or completing suicide, receiving housing support, or income support.

Conclusions Concussion was associated with an increased risk for several adverse psychosocial outcomes. Identifying risk factors for adverse psychosocial outcomes would assist in intervention development.

Learning Outcomes Concussion prevention efforts need to be maximized to prevent long-term adverse outcomes.