The headache of terror: A matched cohort study of adolescents from the Utøya and the HUNT Study.

OBJECTIVE To elaborate the risk of headache among adolescent survivors exposed to terror. METHODS On July 22, 2011, a lone man opened gunfire, killing 69 people at a summer camp for adolescents on the Utøya islet in Norway. All 358 adolescent survivors 13 to 20 years of age were invited to participate in the Utøya interview study. Among the 213 (59%) respondents, half (49%) were male, the mean age was 17.7 years, and 13 (6%) were severely injured. For each survivor, 8 matched controls were drawn from the population-based Young-HUNT3 Study, conducted between 2006 and 2008, with a participation rate of 73%. Recurrent migraine and tension-type headache (TTH) over the past 3 months served as main outcomes and were measured 4 to 5 months after the mass shooting with a validated headache interview, in accordance with the International Classification of Headache Disorders. RESULTS After exposure to terror, the odds ratio for migraine was 4.27 (95% confidence interval 2.54-7.17) and for TTH was 3.39 (95% confidence interval 2.22-5.18), as estimated in multivariable logistic regression models adjusted for injury, sex, age, family structure and economy, prior exposure to physical or sexual violence, and psychological distress. The observed increased risk of headache in survivors was related largely to an increase in weekly and daily headaches. CONCLUSIONS Exposure to terror increases risk of persistent weekly and daily migraine and TTH in adolescent survivors, above expected levels. The terrors of other violence may similarly increase the risk of frequent headaches. After severe psychological traumas, interventions may need to address survivors' pain to hinder chronification.