Newswise — Adolescents who identify as gay, lesbian, bisexual or other sexual minority are twice as likely to attempt suicide or self-harm than adolescents who identify as heterosexual, according to a new study from Indiana University.

While prior research has found a link between suicidality and sexual orientation, few studies have been able to rule out other possible explanations for the link. The IU study compared nearly 7,000 twins in what they call a “co-twin control design”, which allowed them to exclude other factors that the twins shared.

“It is possible that many children who identify as a sexual minority are from families with increased risk for suicidality and the association between sexual minority and suicidality is not due to the risk of sexual minority identity, but rather to shared familial factors,” said lead author Lauren O’Reilly, of the Department of Psychological and Brain Sciences in IU Bloomington’s College of Arts and Sciences. O’Reilly is a clinical psychology researcher focusing on the origins of suicidal behavior and how the healthcare system treats it.

The findings yielded a robust association between sexual orientation and suicide attempt and self-harm when comparing within twin pairs, a 50 percent increased odds for sexual minority adolescents compared to their heterosexual siblings.

According to O’Reilly, the study’s results suggests “something unique to the experience of being a sexual minority youth related to self-harm and suicide attempt, as well as something they may share with other minorities such as discrimination and stigma, which may trigger the propensity to suicide attempt and self-harm.”

Identifying segments of the adolescent population at the greatest risk for self-harm or suicide makes it possible to develop more appropriate and effective treatments.

Using a comprehensive Swedish dataset, the researchers tracked 6,926 sets of twins at three different junctures over a six- or nine-year period, age 9 or 12, age 15 and age 18. The large dataset included sets of twins that differed in their report of their sexual orientation. The data allowed the researchers to eliminate the genetic or environmental factors that twins shared as possible explanations for the associations between sexual orientation and suicide attempt and self-harm. If shared factors were at work, the heterosexual twin would have a similar risk for suicide attempt or self-harm as their twin.

The dataset also provided information on pre-existing mental health conditions such as depression, anxiety, oppositional, conduct and eating problems, which enabled the researchers to exclude the conditions as a potential explanation for the association between sexual orientation and suicide attempt and self-harm.

“Suicide and suicide attempts are a major public health problem,” said Brian D’Onofrio, principal investigator of the study and a professor in the Department of Psychological and Brain Sciences. “We know that such problems are not experienced the same across all groups. We focused on a group of adolescents that have historically been marginalized. The large study and rigorous methods help us better understand why sexual minority adolescents are at greater risk for suicidal behavior.”

Gay, lesbian, bisexual and other sexual minority adolescents (for example, pansexual and asexual) experience a stress similar to that which other minorities experience, O’Reilly noted. The study highlights the need, she said, “to screen sexual minority adolescents for suicidality, as well as to address homophobia and its damaging effects.”

O’Reilly pointed out that goal of such screening is not to attempt to change an adolescent’s sexual orientation, but to change the psychological impact of a culture that precipitates suicidal behavior and to understand the mechanisms at work.

Cross-cultural Implications

Studying suicide has unique challenges, such as finding a large enough population sample to reach statistically meaningful claims. With its vast database of information, the Child and Adolescent Twin Study in Sweden resolved this problem along with other scientific obstacles, providing a rare resource for analyzing the relationship between suicide attempt and self-harm and sexual orientation in adolescents.

However, as a specifically Swedish sample, its generalizability to other nationalities varies, O’Reilly noted.

“If you took a national screenshot of how these things are accepted as well as treated politically in Sweden vs. the U.S., you would see some important differences,” she said. “Translated to an American cultural context, where it is generally more difficult to go on with daily life, go to school or come out to family members than in Sweden, you might expect an even greater risk for suicide attempt and self-harm among sexual minority adolescents.”

For example, while 90 percent of sampled individuals in Sweden agreed that same-sex couples should be allowed to marry, only 67 percent of Americans believed that same-sex marriage should be recognized with the same rights as non-same-sex marriage. While Sweden has federal protections against LGBTQ+ discrimination, the U.S. does not.

The Swedish data also does not provide information on racial identities. In the more diverse U.S. population, the intersectionality of race and sexual orientation may be related to a more heightened sense of stigma and discrimination.

Overall, the study has critical implications for the mental health of sexual minority adolescents in the U.S. and other countries with fewer legal protections and greater discrimination than Sweden, O’Reilly noted, and can serve as “a call to action in the U.S. and across the globe.”

The study, “Sexual orientation and adolescent suicide attempt and self-harm: a co-twin control study,” was published online this fall in The Journal of Child Psychology and Psychiatry.

In addition to O’Reilly and D’Onofrio, researchers include Erik Pettersson and Paul Lichtenstein from the Karolinska Institute in Sweden, Kelly Donahue from the IU School of Medicine, Patrick D. Quinn from the IU School of Public Health, E. David Klonsky from the University of British Columbia in Canada, Sebastian Lundstrom from the University of Gothenburg in Sweden, Henrik Larsson of the Karolinska Institute and Orebro University in Sweden.

The study was funded by grants from the American Foundation for Suicide Prevention, the National Institutes of Mental Health and the National Institute on Drug Abuse.

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