In this sample of 123 adolescents with concussion, therewas a 5-fold increase in odds of clinically elevated anxiety, as well asincreased mental health symptoms (anxiety, depression, anger, and disruptivebehaviours), among adolescents with PTH relative to those without PTH.Adolescents with headache following concussions are vulnerable to worse mentalhealth outcomes, particularly anxiety, and may benefit from routine monitoringof mental health symptoms for early detection and intervention. This evidence concerns the gene PTH and major depressive disorder.