San Francisco entrances people. Photographers capture more images of the Golden Gate Bridge than any other bridge in the world.1 And only the Nanjing Yangtze River Bridge in China surpasses the Golden Gate as a destination for dying by suicide.2 At least 1,700 people reportedly have plunged from the bridge to their deaths since its opening in 1937.3
Despite concerted efforts by bridge security, the local mental health community, and a volunteer organization – Bridgewatch Angels – suicides continue at the pace of about 1 every 2 weeks. After more than 60 years of discussion, transportation officials allocated funding and have started building aon the Golden Gate.
Extrapolating from the success of barriers built on other bridges that were “suicide magnets,” we should be able to assure people that suicide deaths from the Golden Gate will dramatically decrease, and perhaps cease completely.4 Certainly, some in the mental health community think this barrier will save lives. They support this claim by citing research showing that removing highly accessible and lethal means of suicide reduces overall suicide rates, and that suicidal individuals, when thwarted, do not seek alternate modes of death.
I support building the Golden Gate suicide barrier, partly because symbolically, it should deliver a powerful message that we value all human life. But will the barrier save lives? I don’t think it will. As the American Psychiatric Association prepares to gather for its annual meeting in San Francisco, I would like to share my reasoning.
What the evidence shows
The most robust evidence that restricting availability of highly lethal and accessible means of suicide reduces overall suicide deaths comes from studies looking at self-poisoning in Asian countries and Great Britain. In many parts of Asia, ingestion of pesticides constitutes a significant proportion of suicide deaths, and several studies have found that, in localities where sales of highly lethal pesticides were restricted, overall suicide deaths decreased.5,6 Conversely, suicide rates increased when more lethal varieties of pesticides became more available. In Great Britain, overall suicide rates decreased when natural gas replaced coal gas for home heating and cooking.7 For decades preceding this change, more Britons had killed themselves by inhaling coal gas than by any other method.
Strong correlations exist between regional levels of gun ownership and suicide rates by shooting,8 but several potentially confounding sociopolitical factors explain some portion of this connection. Stronger evidence of gun availability affecting suicide rates has been demonstrated by decreases in suicide rates after restrictions in gun access in Switzerland,9 Israel,10 and other areas. These studies show correlations – not causality. However, the number of studies, links between increases and decreases in suicide rates with changes in access to guns, absence of changes in suicide rates during the same time periods among ostensibly similar control populations, and lack of other compelling explanations support the argument that restricting access to highly lethal and accessible means of suicide prevents suicide deaths overall.
The installation of suicide barriers on bridges that have been the sites of multiple suicides robustly reduces or even eliminates suicide deaths from those bridges,11 but the effect on overall suicide rates remains less clear. Various studies have found subsequent increases or no changes12-14 in suicide deaths from other bridges or tall buildings in the vicinity after the installation of suicide barriers on a “suicide magnet.” Many of the studies failed to find any impact on overall suicide rates in the regions investigated. Deaths from jumping off tall structures constitute a tiny proportion of total suicide deaths, making it difficult to detect any changes in overall suicide rates. In the United States, suicides by jumping/falling constituted 1%-2% of total suicides over the last several decades.15
If we know that restricting highly lethal and accessible methods of killing reduces suicide deaths, why would I question the value of the Golden Gate suicide barrier in preventing overall suicide deaths?