The aim of the Childhood and Adolescent Migraine Prevention (CHAMP) study is to determine the most effective preventive agent to use in children and adolescents.CHAMP is a double-blinded, placebo-controlled, multicenter, comparative effectiveness study of amitriptyline and topiramate for the prevention of episodic and chronic migraine, designed to mirror real-world practice, sponsored by the US National Institute of Neurological Disorders and Stroke/National Institutes of Health (U01NS076788)