Each year some 1,500 Swedes decide to end their lives. The reasons are often personal and can be numerous, such as mental or physical disease.
Previous research has shown that people’s choices are affected by their surroundings. Various types of behaviour, feelings, and attitudes are spread in social networks. The researchers at Stockholm University and the University of Oxford have studied whether such a drastic step as taking your life can also be influenced by others. The study is based on comprehensive register data on all individuals who lived and worked in Stockholm County during the 1990s.
”By tying together relatives and colleagues, we could see which individuals who had someone in the family or in the workplace who committed suicide. Then we studied whether the suicides of others increased or decreased their risk of committing suicide when we have controlled for other known risk factors,” says Monica K. Nordvik, PhD, who during her doctoral studies in sociology at Stockholm University was one of the researchers who carried out the study.
The researchers discovered that the risk of suicide increased markedly both for women and men if someone in the family had taken their own life, something that is supported by previous research. But the study also showed that men’s suicide risk increased if they have had one or more work mates who had committed suicide in the last year. On the basis of how many suicides, statistically speaking, can be ascribed to this phenomenon, it turns out that workplace exposure prompts more new suicides than that within the family.
”Since there are so many more individuals who experience a suicide at their workplace, the aggregate effect is greater than what can be ascribed to the family, even though a suicide in the family obviously has a greater impact on the suicide risk of the individual in question,” says Professor Peter Hedström at Oxford University.
All in all the study indicates that twice as many suicides among men can be ascribed to the “contagious effect” of the workplace than to that of the family.
Of course, such a study raises issues of research ethics and what information researchers can access about people.
“The data we work with is de-identified. This means  that we can’t see who it is or where he or she works, since all such information has been replaced with number codes,” says Monica K. Nordvik.
Peter Hedström, Ka-Yuet Liu, Monica K. Nordvik Interaction Domains and Suicide: A Population-based Panel Study of Suicides in Stockholm, 1991-1999 Social Forces - Volume 87, Number 2, December 2008, pp. 713-740.

The article is also part of Monica K. Nordvik’s doctoral dissertation in sociology, Contagious Interactions – Essays on social and epidemiological networks.

For more information, please contact:
Monica K Nordvik, PhD., phone: +46 (0)63-199738, e-mail  monica.nordvik@fhi.se
Peter Hedström, professor, University of Oxford, e-mail peter.hedstrom@nuffield.ox.ac.uk