Do psychosocial factors mediate sexual minorities' risky sexual behaviour? A twin study

Abstract

Objectives: Risky sexual behavior among sexual minorities (lesbian, gay, and bisexual individuals) are partly attributed to mental health and other social disparities; but this may be confounded by correlated genetic and environmental influences. As preregistered, the present study investigated indirect associations between sexual minority status and increased lifetime sexual partners through increased psychosocial adversity (depressive and anxiety symptoms, intimate partner violence, and early life adversities) and substance use (alcohol, cannabis, and other illicit drugs), confounding by correlated genetic and environmental influences, and sex differences in these relationships.

Method: The sample comprised sexual minority and heterosexual twins who participated in the first and second phases of the latest wave of data collection in the U.K. population-based Twins Early Development study cohort (June 2017 through February 2019; n = 9,697 and 8,718, respectively, M_age = 22.3 ± .92 years). Structural equation modeling was used to specify psychosocial adversity and substance use as mediators while genetic and environmental confounding was further determined by biometrical genetic analyses in which similarities in identical and nonidentical twins were compared.

Results: Increased psychosocial adversity and substance use fully mediated increased lifetime sexual partners in sexual minority women while this effect was partial (31.1%) in men. The best-fitting genetic models indicated that these relationships were not confounded by correlated genetic and environmental influences.

Conclusions: The relationships between sexual minority status, psychosocial adversity, substance use, and sexual health disparities appeared independent of genetic and environmental influences. Individual and systemic interventions to reduce psychosocial disadvantage and substance use can also decrease sexual health disparities among sexual minorities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Figure 1. Phenotypic factor mediation model in males and females

Note. Path diagram depicting mediation relationships between Sexual Orientation (SO), Psychosocial Adversity (PSA), SU (Substance Use) and Lifetime Sexual Partners (LSP) latent factors with standardized path coefficients. Factors were scaled by fixing one loading per factor to 1. SO = Sexual orientation, Dep = Depressive symptoms, Anx = Generalized anxiety symptoms, Alc = Alcohol Use, Can = Cannabis use, Drg = Other illicit drug use, ELA = Early-life adversity, IPV = Intimate partner violence. e₁ – e₇ = residual variances for corresponding indicator variables. Solid lines indicate significant paths while dotted lines indicate nonsignificant paths.

Figure 2.. Biometric mediation model in males and females

Note. Path diagrams depicting mediation relationships between Sexual Orientation (SO), Psychosocial adversity (PSA), Substance use (SU) and Lifetime Sexual Partners (LSP) latent factors, standardized variance component influences on latent factors and standardized path coefficients. Factors were scaled by fixing one loading per factor to 1. SO = Sexual orientation, Dep = Depressive symptoms, Anx = Generalized anxiety symptoms, ELA = Early-life adversity, IPV = Intimate partner violence, Drg = Other illicit drug use, Alc = Alcohol Use, Can = Cannabis use. A_f1-A_f4, C_f1-C_f4 and E_f1-E_f4 = Factor-specific additive genetic and shared and individual-specific environmental influences respectively (in blue). A_s2-A_s8, C_s2-C_s8 and E_s2-E_s8 = Variable-specific additive genetic, shared and individual-specific environmental influences respectively (in red). Solid lines indicate significant paths while dotted lines indicate nonsignificant paths.