A recent study published in JAMA Pediatrics suggests that the legalization of same-sex marriage is associated with a reduction in the proportion of high school students who reported making a suicide attempt. This study indicates that governmental policies regarding non-normative sexuality may have an influence on mental health outcomes for adolescents.
The study used data from the state-level Youth Risk Behavior Surveillance System, which tracks dangerous and risky behaviors exhibited by teenagers. Its authors used data from forty-seven states, including thirty-two states that implemented same-sex marriage policies between 2004-2015. They looked at suicide behaviors in the full population of high school students and then did a secondary analysis using the subset of students who self-identified as belonging to a sexual minority (gay, lesbian, bisexual, or unsure about their sexual identity).
One limitation of using this type of data is that it depends on self-reporting of suicide attempts, which is tricky because suicide attempts are typically under-reported. This approach also means that the researchers did not include any information about teens who died from their suicide attempts; it only captures teens who attempted suicide but survived. This methodological limitation may seem like a big one, but the proportion of suicide attempts that result in teen deaths is very small, so suicide attempts are reasonable proxy for overall teen mental health.