Research has consistently shown that if access to a single means of suicide is restricted, overall suicides decrease. To review a comprehensive summary of these studies, see Journal of the American Medical Association (JAMA), 2005, 294; 2064-2074
Some of the research that supports this conclusion is summarized below:
More suicides in the U.S. are by gunshot than by any other means. Seventeen published studies show the rate of suicide death in gun-owning households is at least three times greater than in households where guns are not present. But where guns are present, proper safety procedures—use of gunlocks and securing the ammo—cuts the risk of suicide by two-thirds. (See: Shenassa, 2004)
Use of some prescription and over-the-counter drugs has been a means of suicide for many years. However, as the availability of these drugs changes, so does the number of suicides. In Australia, suicide from sedative overdose increased when the drugs were easier to get and declined when access was restricted. In the U.K., limiting access to an over-the-counter drug by simply shifting from bulk packaging to small-unit packaging reduced suicides. (See: JWEM, July 2001)
The city of Bern, Switzerland had an unusually high rate of suicide by jumping—more than 28percent of all suicides. Several sites were a problem but the greatest was Muenster Terrace. In 1998, a safety net was installed to prevent jumps, and it was successful in stopping jumps from that site. Researchers also found that the overall rate of jumps declined—indicating that suicidal individuals did not simply go to another site to jump. (Reisch, 2005)
Bristol England is home to the world’s oldest suspension bridge, the Clifton Bridge. The bridge was the site of 41 suicides between 1994 and 1998. A partial barrier was built in 1998, and the number of suicides from the bridge was reduced to 20 over the next five years. Researchers checked the jumping deaths from other bridges in the area and found no significant increase in jumps from those other structures. (Bennewith, 2007)
Data on the suicide statistics from the Memorial Bridge in Augusta, ME was examined from 1960 through 2005. A safety fence was installed in 1984 and suicides from the site stopped. The number of suicides by jumps or falls elsewhere in the area remained unchanged, indicating that prospective jumpers from Memorial Bridge did not simply go elsewhere. (Pelletier, 2007)
Dr. Richard Seiden of U.C. Berkeley's School of Public Health investigated the lives of more than 500 people removed from the Golden Gate Bridge before they could jump. He found that, for an average of 26 years after the suicide attempt, 94 percent of these people were either still living or had died of natural causes.
Thirty people are known to have jumped from the Golden Gate Bridge and lived. Of these, only three are known to have subsequently committed suicide.