On 20 February 2017, the journal JAMA Pediatrics published a study by Johns Hopkins public health postdoctoral researcher Julia Raifman and colleagues that sought to address a simple question: “Are state same-sex marriage policies [which legalize the practice] associated with a reduction in adolescent suicide attempts?”

Their findings were clear: There is a statistically significant association between the adoption of same-sex marriage and reduced teenage suicide attempts, as reported by the Los Angeles Times:

More specifically, in a 16-year period during which changes in state marriage laws were sweeping the nation, states that adopted laws allowing same-sex marriage saw an immediate decline in suicide attempts by gay, lesbian and bisexual high school students — a group in which attempted suicide is two to seven times more common than among their heterosexual peers.

To reach this conclusion, the researchers utilized demographic data regarding teenage suicide attempts from the Centers for Disease Control and Prevention’s biannual survey of high school student risk behavior (the Youth Risk Behavior Surveillance System). The team analyzed data from from 1 January 1999 (five years prior to the first same-sex marriage policy in Massachusetts) through 31 December 2015.

The researchers used this information to compare year-to-year changes in the number of suicide attempts between different states and between sexual minorities (defined by the researchers as individuals who responded that they were gay, lesbian, bisexual, or not sure, when asked ‘Which of the following best describes you?’):

We focused on the differences in suicide attempts within each state before and after the implementation of same-sex marriage policies relative to year-to-year differences in states that did not implement same-sex marriage policies.

After a number of statistical tests, they found a significant drop in attempted suicides:

Same-sex marriage policies were associated with a 0.6–percentage point […] reduction in suicide attempts, representing a 7% relative reduction in the proportion of high school students attempting suicide owing to same-sex marriage implementation. The association was concentrated among students who were sexual minorities.

This finding confirmed the researchers’ hypothesis that state same sex marriage policies would be associated with reductions in the proportion of adolescents attempting suicide. This hypothesis was informed in part, they said, by research that previously demonstrated an increase in psychiatric disorders following legislation actively banning same-sex marriage.

The lead author on the study that showed that increase, Columbia professor Mark Hatzenbuehler, wrote an editorial to accompany this new research, arguing that it highlights the importance of what he terms “structural stigma”:

Laws that affect sexual minority populations have proliferated in the last 2 decades and include, among others, same-sex marriage, employment nondiscrimination, fostering and adoption of children among same-sex couples, religious exemptions, conversion therapy, and protections against hate crimes. […] A national conversation has emerged about the prevention of suicides among LGB populations. Yet comprehensive, evidence-based suicide prevention programs still do not exist for adolescents who are sexual minorities. Although no single factor can fully explain a complex behavior such as suicide, the study by Raifman and colleagues suggests that structural stigma—in the form of state laws—represents a potentially consequential but thus far largely overlooked contextual factor underlying suicidality in LGB youth.

The authors were careful to point out that they were merely demonstrating an association, and that they cannot make inferences about the specific mechanism by which implementation of same-sex marriage policies contributes to a reduction in adolescent suicide attempts — they can only note that the association is a robust one.

The researchers concluded their study by urging policymakers to “consider the mental health consequences of same-sex marriage policies.”