Effect of 11 September 2001 terrorist attacks in the USA on suicide in areas surrounding the crash sites

Background The terrorist attacks in the USA on 11 September 2001 affected suicide rates in two European countries, whereas overall US rates remained stable. The effect on attack site rates, however, has not been studied. Aims To examine post-attack suicide rates in areas surrounding the three airline crash sites. Method Daily mortality rates were modelled using time series techniques. Where rate change was significant, both duration and geographic scope were analysed. Results Around the World Trade Center, post-attack 180-day rates dropped significantly (t=2.4, P=0.0046), whereas comparison condition rates remained stable. No change was observed for Pentagon or Flight 93 crash sites. Conclusions The differential effect by site suggests that proximity may be less important that other event characteristics. Both temporal and geographic aspects of rate fluctuation after sentinel events appear measurable and further analyses may contribute valuable knowledge about how sociological forces affect these rates.