Post-traumatic Stress Disorder (PTSD) is one of the most prevalent anxiety disorders, affecting seven to eight percent of the US population at some point in their lives. In a recent study released in the European Journal of Psychotraumatology, researchers attempted to identify factors that may amplify the risk of developing the disorder after experiencing traumatic events. Their findings shed light on how exposure to early-life violence and sexual abuse may highly increase the chances of developing PTSD associated with traumatic events later in life.

The Study

The research team, headed by Dag Nordanger Ph.D., examined data from a comprehensive, long-term study of the physical and mental health of over 10,000 Norwegian high school students. The researchers centered their study on the tragic fallout of the Oslo Terror events, two terrorists attacks which took the lives of 77 people and injured over 300 in 2011.

The team found that the terror attacks affected the psychological states of these students even when they had no close proximity to the events, nor knew anyone that was exposed. Many of the students experienced PTSD symptoms even if their relation to the attacks consisted only of watching media coverage.

The research team then examined the incidence of early-life traumatic incidents in the students, assessing their prior exposure to violence, witnessing of violence, and unwanted sexual acts. The findings showed that those who had been exposed to these traumatic early life events were more likely to develop PTSD following the terror attacks. Students who experienced sexual abuse earlier in their life were twice as likely to experience PTSD symptoms following the attack. For adolescents with early exposure to violence the risk was 50 percent greater.

The Results

The results of the research illuminate a strong correlation between negative childhood experiences and the vulnerability to PTSD. “Terror events can have a more destabilizing impact on victims of prior adversities, independent of their level of exposure," the study concluded.

Noranger believes that the results of this study will create a larger emphasis on preventing traumatic experiences in children. He stated that the “findings are important because they tell us that prevention of violence and abuse early in life also means preventing negative reactions to major incidents that occur later."

Date of original publication:


European Journal of Psychotraumatology

Dag Ø. Nordanger, Kyrre Breivik, Bente Storm Haugland, Stine Lehmann, Magne Mæhle, Hanne Cecilie Braarud, Mari Hysing. Prior adversities predict posttraumatic stress reactions in adolescents following the Oslo Terror events 2011. European Journal of Psychotraumatology, 2014; 5 (0) DOI:10.3402/ejpt.v5.23159