Effects of changes in permit-to-purchase handgun laws in Connecticut and Missouri on suicide rates

Objective: In 2013, more than 40,000 individuals died from suicide in the United States. Restricting access to lethal means has the potential to prevent suicide, as suicidal thoughts are often transient. Permit-to-purchase (PTP) laws for handguns could potentially reduce suicides by making it more difficult for persons at risk of suicide to purchase a handgun. Methods: We used a quasi-experimental research design with annual, state-level suicide data to evaluate changes to PTP laws in Connecticut and Missouri. Data were analyzed for 1981-2012. We used synthetic control modeling as the primary method to estimate policy effects. This methodology provided better prediction of pre-PTP-law-change trends in the two states with PTP law changes than econometric models and is thus likely to provide more accurate estimates of policy effects. Results: The synthetic control model estimated a 15.4% reduction in firearm suicide rates associated with Connecticut's PTP law. Missouri's PTP law repeal was associated with a 16.1% increase in firearm suicide rates. Evidence that PTP laws were associated with non-firearm suicide rates was mixed in Connecticut and negative in Missouri. Conclusion: The findings are consistent with prior research linking firearm availability to increased risk of suicide and lower suicide risks associated with PTP handgun laws.