Exposure to terror may increase risk of migraine, other headaches

The study involved the teenage survivors of Norway's largest mass killing. In 2011, a lone gunman opened fire at a youth summer camp on Utøya Island, killing 69 people and severely wounding 33. All survivors experienced terror, many lost friends and some risked drowning as they tried to escape the island.

"We know a lot about the psychological effects of terror attacks and other extreme violence on survivors, but we don't know much about the physical effects of these violent incidents," said study author Synne Øien Stensland, MD, PhD, of the Norwegian Centre for Violence and Traumatic Stress Studies in Oslo. "Our study shows that a single highly stressful event may lead to ongoing suffering with frequent migraines and other headaches, which can be disabling when they keep people from their work or school activities."

The 358 teenage survivors were invited to participate in the study. Of the 213 who participated, the average age was 18 and six percent were severely injured in the attack. Participants were interviewed about their headache frequency four to five months after the attack. Their responses about headache type and frequency were compared to the responses of 1,704 young people of same sex and age who had not experienced terror.

The teens who had been exposed to terror were four times more likely to have migraines and three times more likely to have frequent tension headaches than the teens who were not exposed to terror.

These findings remained the same after adjusting for injury, sex, prior exposure to physical or sexual violence, and psychological distress.

Among the female participants, 80 of the 109 who were exposed to terror, or 73 percent, had recurrent headaches, compared to 325 of the 872 who were not exposed, or 37 percent. For male participants, 43 of the 104 terror survivors had headaches, or 41 percent, compared to 158 of the 832 with no exposure, or 19 percent. The terror survivors were much more likely to have daily or weekly headaches than those with no exposure.

"We suspected that headaches would increase for terror survivors, and the increase was over and above what might be expected based on psychological distress and other risk factors," said Stensland. "This suggests that we may need to figure out ways to help people right after events like terror attacks to help reduce the potential of frequent and disabling headaches. In many cases with severe headaches, treatments can be most helpful early on before the condition becomes chronic."

One limitation of the study was the lower response rate among survivors with high symptom levels, which could have led to an underestimation of risk.