Background Engaging in sport has been suggested to be mitigate against psychological distress. Using a prospective-longitudinal design, we examine whether sport participation is associated with reduced psychological difficulties in adolescents and whether associations differ by sport and personal characteristics.

Methods 17 550 adolescents from grade 7 to 10 (mean age=14.4 years old) self-reported on sport participation, depressive symptoms, social anxiety symptoms and loneliness in Spring 2007 and 1 year later. Analyses tested the association between sport participation and subsequent psychological difficulties using linear regression, while adjusting for pre-existing psychological and sociodemographic characteristics. Analyses also verified whether associations differed by sport frequency (weekly/more than weekly) and type (team/individual) using Wald tests of parameter constraints, as well as sex, age and pre-existing psychological difficulties using interaction terms.

Results After adjusting for potential confounders, sport participation predicted lower social anxiety symptoms (beta=−0.02 (−0.04, −0.01)) and loneliness (beta=−0.04 (−0.05, −0.02)), but not depressive symptoms. Moderation analyses showed that sport participation predicted greater reductions in depressive symptoms, social anxiety symptoms and loneliness in adolescents with higher baseline scores on each outcome. Associations did not differ by sport frequency and type, sex and age. Post hoc analyses revealed bidirectional associations between sport participation and social anxiety symptoms and loneliness.

Conclusions Sport participation predicts small reductions in adolescent psychological distress. Reductions seem most important in youth experiencing greater pre-existing psychological difficulty. Our findings suggest that sport participation represents a protective factor that supports psychological resilience in at-risk youth.