particularly well suited to the exploration of “third variables” that could explain the link between firearms and suicide in the United States.
While suicide has rarely been the basis for public support of the passage of specific gun laws, suicide prevention may be the unintended by-product of such laws. For example, federal ownership standards that have been set by the Brady Handgun Violence Prevention Act might reduce the risk of gun suicide among several high-risk groups, including persons with a history of violent behavior, substance abuse, and severe mental disorder. Gun storage laws might reduce the risk of suicide among children and adolescents; gun buy-backs might reduce the stock of infrequently used guns that might be used for suicide, and cooling off periods could reduce the use of guns in suicides motivated by transient suicidal states. But gun policies could also increase the risk of suicide. For example, mental health advocates have opposed the creation of registries of persons with a history of mental illness, arguing that the stigma of appearing in a state-sponsored registry could lead some persons to refuse needed mental health treatment, thus increasing rather than decreasing the risk of a lethal outcome.
Tables 7-4, 7-5, and 7-6 summarize studies of the effects of specific gun laws. Several cross-sectional and time-series studies do report a decline in firearm suicides in response to gun control legislation, but so far there is little evidence for an effect on the overall risk of suicide.
We identified 14 cross-sectional studies of the association between strictness of gun control laws and rates of suicide; these studies are summarized in Table 7-4. Overall, most studies found that stricter gun laws were associated with lower gun suicide rates. For example, 8 out of 9 studies found that states or cities with stricter gun control laws have lower rates of gun suicide. These studies have used a variety of methods for classifying the types and strictness of gun laws; it is worth noting that many of them compare the same geographic areas over the same time intervals, so they should not be regarded as independent samples. In general, laws restricting the buying and selling of firearms have been associated with lower rates of firearm suicide, but laws governing the right to carry firearms seem to have no association.
Lower gun suicide rates have sometimes been associated with higher nongun suicide rates, and the findings regarding overall suicide rates have been less consistent: 5 out of 11 studies found an association between stricter gun laws and overall rates of suicide, another 5 studies found no significant association, and 1 study produced mixed results.