The number of suicides fell in England and Wales after the London bombings on 7 July 2005 researchers have found. A second significant reduction occurred after a wave of failed terrorist attacks two weeks later.
A similar pattern was seen after the attacks which destroyed the World Trade Centre on 11 September 2001.
Psychologists believe traumatic national events such as terrorist attacks help potentially suicidal people to feel less alone and more a part of society. Dr Mario Cortina-Borja, from University College London, and Emad Salib, from the University of Liverpool, analysed daily suicide counts between 1 January 2001 and 31 December 2005.
A small but significant reduction in suicide rates occurred five days after the 7 July attacks on London's transport system in which 52 people died.
Suicide rates fell again on 21 July, when bombers targeted London Underground trains and buses but did not detonate devices. The fall in suicides on both days was about 40 per cent.