A controlled follow-up study of adolescents exposed to a school shooting--psychological consequences after four months.

Background: In November 2007, a student shot eight people and himself at Jokela High School, Finland. This study aims to evaluate the long-term effects of exposure to a school shooting among adolescents.

Method: Associations between psychological outcomes and background factors were analysed and compared with "comparison students" four months after the incident. A questionnaire including Impact of Event Scale (IES) and General Health Questionnaire (GHQ-36) was used.

Results: Half of the females and a third of the males suffered from posttraumatic distress. High level of posttraumatic distress (IES≥35), predicting PTSD, was observed in 27% of the females and 7% of the males. The odds ratio was 6.4 (95% confidence interval 3.5-10.5) for having high levels of posttraumatic distress. Severe or extreme exposure and female gender were found to increase the risk. Forty-two percent of the females and 16% of the males had psychiatric disturbance (GHQ≥9). Severe or extreme exposure, older age and female gender increased the risk. Perceived support from family and friends was found to be protective.

Conclusions: The observed risk and protective factors were similar to earlier studies. Follow-up will be essential in identifying factors predicting persisting trauma-related symptoms in adolescence.