A Household Handgun Divestment and Suicide Risk

Access to firearms affects suicide risk. To date, however, there are no published studies that estimate how divestment from firearms may reduce suicide risk. A focus on divestment is a step closer to an understudied but practical and promising public health initiative of encouragement of voluntary disarming. Much of the current firearm-related injury prevention research, activities, and advocacy focuses on interventions at the point of purchase, but such efforts do not address the risk posed by the enormous existing stock of weapons: one-third of American households currently have at least one firearm. In an ongoing research project funded by the American Foundation for Suicide Prevention, we have been assessing how personal divestment affects handgun owners' own suicide risk. Here, we propose to extend this line of research by examining how divestment affects the suicide risk of other non-owner adults living in the household. We will use data from the Longitudinal Study of Handgun Ownership and Transfers, a cohort that follows approximately 28 million California residents, handgun owners and non-owners, for up to 12.2 years. Our aims are (1) to estimate the effect of handgun owners' divestment on the risk of suicide among adults who live in households with the handgun owner but do not themselves own a handgun; and (2) to assess the robustness of the estimated effect using established causal inference methods.