A new study published in Behavior Genetics provides evidence of a bidirectional relationship between same-sex attraction and psychological distress. The findings indicate that experiencing attraction to people of the same sex can result in higher levels of depression and anxiety, but this relationship goes both ways – psychological distress can also result in an increase in same-sex attraction.
Research has demonstrated that individuals who are sexually attracted to people of the same sex tend to experience higher levels of psychological distress, including depressive symptoms and anxiety, compared to those who are exclusively heterosexual. But most of the research on this topic has been cross-sectional, which limits its ability to draw conclusions about causality. The authors of the new study sought to help fill this gap in the literature.
“I started out investigating the mental health of lesbian, gay and bisexual (LGB) individuals in Nigeria,” said study author Olakunle Oginni, a postdoctoral research associate at King’s College London and lecturer at Obafemi Awolowo University.
“This was because there was little research on LGB Nigerians’ mental health despite the wide recognition of higher mental health difficulties among LGB individuals. I developed expertise in the twin design during my PhD and used this method to show that the association between sexual orientation and mental health is not due to overlapping genetic influences. The present study is significant because it demonstrates how being LGB can ’cause’ psychological distress (anxiety and depressive symptoms), and potential mechanisms for this effect.”
The study analyzed data from the UK Twins Early Development Study, a large twin cohort investigating genetic and environmental factors that shape individual differences in cognitive and learning abilities, behavior, and emotions. The data analyzed in the current study were collected in two phases between June 2017 and February 2019. The final sample comprised 9,697 and 8,718 individuals from the first and second phases, respectively. The average age of the participants during this wave of data collection was 22.3 years.
Importantly, the inclusion of monozygotic and dizygotic twins allowed the researchers to control for potential genetic confounds.
The study used various assessments to gather information about same-sex attraction, depressive symptoms, generalized anxiety disorder, victimization, early-life adverse experiences, and childhood gender nonconformity. Genotype data was also collected at ages 12- and 16-years, which the researchers used to calculate the genetic propensity for same-sex attraction and psychological distress.
Of the entire sample, 81% of participants reported being exclusively attracted to the opposite sex, while the remaining reported various degrees of same-sex attraction, with 1.9% mostly same-sex attracted and 11.5% mostly attracted to the opposite sex. More females (21.4%) reported being same-sex attracted compared to male participants.
The researchers found a positive correlation between same-sex attraction and psychological distress, meaning that increasing levels of same-sex attraction were associated with higher levels of psychological distress. Victimization (such as being made fun of or being physically bullied) was also significantly correlated with both same-sex attraction and psychological distress. These findings support minority stress theory, which suggests that the experiences that come with being a member of a marginalized group can lead to higher levels of mental health issues.
The results of the study indicate that “the higher rates of psychological distress among LGB people is not genetic: victimization is one way that being LGB can cause psychological distress,” Oginni told PsyPost.
The researchers used a statistical technique known as Mendelian Randomization-Direction of Causation models to investigate potential causal relationships. The method is based on the principles of Mendelian inheritance, which dictate that genetic variants are randomly assigned at conception and should not be influenced by environmental or lifestyle factors.
Interestingly, the researchers found evidence of a bidirectional relationship between same-sex attraction and psychological distress. Not only did increasing levels of same-sex attraction lead to higher levels of psychological distress — higher levels of psychological distress also led to increasing levels of same-sex attraction.
The reciprocal causation between psychological distress and same-sex attraction was attenuated by higher childhood gender nonconformity. “Being gender nonconforming during childhood was protective against further harmful consequences of psychological distress,” Oginni explained. “To elaborate a little, childhood gender nonconformity is when children behave in ways typical of the opposite sex. Typically, being gender nonconforming in childhood is stressful, so it was interesting to find that it could be protective.”
The findings are mostly in line with another study conducted by Oginni and his colleagues, which examined twin pairs from the Finnish Genetics of Sexuality and Aggression cohort. But the new study, like all research, includes some caveats.
“The study needs to be repeated with an even larger sample,” Oginni told PsyPost. “This is because, even though substantial, we couldn’t show that the effect of sexual orientation on victimization was statistically significant. But we think this was because of how sexual orientation was defined statistically in the study. And then in carrying out the analyses, we tested how sexual orientation might cause psychological distress and vice versa separately. It would be better to test these relationships simultaneously and then see how these relationships change over time.”
“Some further reasons why these results are exciting to me are that this is an innovative way of using genetic data,” Oginni said. “It is also the few times we would be using genetic data to probe the links between sexual orientation and psychological distress. However, we need further research to further elaborate the relationships between sexual minority status and risk for mental health problems.”
The study, “Bidirectional Causal Associations Between Same‑Sex Attraction and Psychological Distress: Testing Moderation and Mediation Effects“, was authored by Olakunle A. Oginni, Kai X. Lim, Qazi Rahman, Patrick Jern, Thalia C. Eley, and Frühling V. Rijsdijk.
