Restricting access to suicide hotspots is an effective public health intervention. Suicide barrier that is going to be erected at Golden Gate Bridge, San francisco is going to be the costliest suicide barrier in the world. The board has set aside 76 million dollars for this. There are concerns from previous research that substitution ( i.e. increased suicide rates in nearby areas) phenomenon might reduce the effect. AN interesting study from Japan adds to this discussion.
Installation of platform screen doors have shown to reduce metro suicides. In japan, blue lights were installed in some railway stations and this was found to reduce suicides there. Matsubayashi et al. (2013) showed that blue light installation reduced suicide rate by 83% in the 10 year period. The same group then examined whether substitution phenomenon occurred with this reduction, the results are reported in this article.
They studies the number of suicides at blue light stations and compared this with neighbouring stations ( to see whether there is a shift),They used the number of suicides in all other stations without blue light as the control group.
The updated data still strongly suggest that blue light reduce suicides. Almost no suicides occurred in stations where blue light was turned on in the evening hours. There was no systematic substitution in neighbouring stations. It also shows that blue light has not become less effective over time.
Present data only looked at jumping from platform. It is possible that people might choose to jump at railway crossing or they might have chosen to go to a station run by a different company. Suicide rate in the area was not compared to show whether blue light had an impact on total suicide rate. The effect shown is only for night-time suicide, which accounts for only 14% of all such suicides.
Comments: Influence of environment in human emotional state is well recognised. Various environmental measures are useful in reducing distress and producing calming effect. It needs to be seen whether such interventions reduce overall suicide rates. It would be interesting to see whether installation of blue lights in acute psychiatric wards have an effect on reducing self harm/aggression incidents.
Summary of the article
Matsubayashi T, Sawada Y, Ueda M. J Affect Disord. 2014 Dec 1;169:57-60