The deadly terrorist attacks in London and New York prompted a fall in the number of suicides in England and Wales, researchers have concluded.
The number fell after the London bombings of 7 July 2005, the failed attacks of 21 July and the earlier attacks that destroyed the World Trade Centre in New York on 11 September 2001.
Experts believe that such traumatic events help potential suicides feel less alone and more a part of society, although this effect lessens as the shock value is reduced over time.
The fall in suicides on both London days was about 40% – similar to the reduction reported after 9/11 in the US. No similar drop in suicide rate had occurred during the same period in the previous four years.
Researchers Dr Mario Cortina-Borja, from University College London, and Emad Salib, from the University of Liverpool, said they were surprised the UK bombings did not have more of an impact on suicide than the US attacks.
They suggest that previous experience of IRA terrorism in Britain may have limited the effect of the London attacks.
Writing in the British Journal of Psychiatry, they said: "The shock value of suicide terrorism and its psychological potency appear to diminish over time as the tactic becomes overused."