Background: The tragic events of 11 September 2001 and televised scenes of the terrorists' homicidal and suicidal acts could have had an impact on the behaviour of some people, who harbour suicidal ideation or homicidal tendencies.
Aims: To assess the effect of 11 September 2001 on the rate of suicide and homicide in England and Wales.
Method: Analysis of the number of suicides (ICD-9 codes: E950-E959), undetermined injury deaths (E980-E989) and homicides (E960-E969) in England and Wales in the 12 weeks before and after 11 September 2001 and during a similar period in the previous two years.
Results: The number of suicides reported in the month of September 2001 was significantly lower than other months in the same year and any September of the previous 22 years in England and Wales. A suicide reduction in men, regardless of age, occurred in the week starting Tuesday 11 September 2001. A reduction in female suicide occurred during the four weeks following the attack. There was no evidence of a similar effect on homicide.
Conclusions: The tragic events of 11 September 2001 appear to have had a brief but significant inverse effect on suicide.The finding of this study supports Durkheim's theory that periods of external threat create group integration within society and lower the suicide rate through the impact on social cohesion.