This study identified 5 substance use patterns among YAs: primarily-alcohol use, polysubstance use (i.e., combustible tobacco, e-cigarette, cannabis, and alcohol use), non-use, cannabis and alcohol co-use, and e-cigarette, cannabis, and alcohol co-use. While primarily-alcohol use and polysubstance use were the most commonly endorsed patterns among both women and men, the profiles of substance use by gender and sexual identify subgroups differed significantly, underscoring the need for additional research identifying mechanisms and intervention targets to decrease high-risk substance use patterns for particular groups.

Consistent with prior research examining tobacco, cannabis, and alcohol use separately (Kerr et al., 2015, Romm et al., 2022, Schuler and Collins, 2020), this study found that bisexual (versus heterosexual) women were more likely to engage in polysubstance use, as well as e-cigarette, cannabis, and alcohol co-use. Bisexual women were less likely than heterosexual women to exhibit the most prevalent pattern—primarily-alcohol use. Greater risk for engaging in polysubstance use may occur for bisexual, but not lesbian women, as bisexual individuals often experience marginalization from both heterosexual and SM communities (Callis, 2013). Bisexual women, in particular, report feeling pressured to “prove” that they belong to the SM community (Cipriano et al., 2022). Among bisexual women—but not bisexual men—experiencing bisexual stigma from the SM community is associated with internalized stigma (Arriaga & Parent, 2019). Women who internalize bisexual stigma may use substances to cope (Hatzenbuehler, 2009, Meyer, 2003). For bisexual YAs, substance use serves functions such as facilitating connection with the SM community (e.g., smoking at parties) and relieving the stress of managing one’s identity differently in heterosexual versus SM social spaces (McQuoid et al., 2019). Targeted substance advertising is prevalent in SM social spaces and may partially account for substance use disparities (Belt et al., 2014, Stevens et al., 2004). SM women, particularly bisexual women (Tan et al., 2021), report greater exposure to tobacco and cannabis advertising than heterosexual women (Romm et al., 2024, Tan et al., 2021). Social spaces such as parties, where multiple substances are often available, may be conducive to polysubstance use for bisexual women who are struggling with bisexual stigma.

Compared to heterosexual men, gay men were less likely to engage in polysubstance use or in e-cigarette, cannabis, and alcohol co-use, and bisexual men were less likely to primarily use alcohol. Despite also being vulnerable to minority stress, bisexual men were less likely to use alcohol and gay men were less likely to engage in polysubstance use patterns characterized by combustible tobacco, e-cigarette, cannabis, and alcohol co-use, as well as e-cigarette, cannabis, and alcohol co-use, relative to heterosexual men. SM men’s lower likelihood of engaging in polysubstance use may be partially driven by their lower likelihood of tobacco use (Romm, Huebner, et al., 2022). In bivariate analyses, gay men displayed higher rates of cannabis and alcohol co-use – but not tobacco use – compared to heterosexual men, perhaps because YAs perceive cannabis-alcohol co-use as more effective for coping with stress than alcohol-only use (Boyle et al., 2021).

Minority stress experiences may be especially prevalent among individuals with multiple, intersecting minoritized identities (e.g., sexual identity, race, ethnicity) (Crenshaw, 1991). Black (versus White) men had greater odds of cannabis-alcohol co-use, and Hispanic (versus non-Hispanic) men had greater odds of polysubstance use. Importantly, however, several racially minoritized groups of participants (e.g., Asian and Black women and men) were less likely than their White peers to exhibit polysubstance use and co-use patterns. Findings underscore the complexity of intersecting identities and the need to disaggregate races, ethnicities, sexual identities, and genders when examining substance use patterns.

Taken together, findings have important implications for future research, policy, and practice. Findings urge researchers to examine specific sexual identity by gender subgroups, as well as the co-occurring use of a range of substances, and intersecting substance use disorders (e.g., dual diagnosis of cannabis and alcohol use disorders) among SMYAs. When weighing the public health impact of products such as e-cigarettes and cannabis, regulatory decision-makers should account for disparities in the prevalence of harmful polysubstance use patterns among SMYAs. Public health messaging campaigns and substance use intervention efforts should focus on the use of both combustible tobacco products and e-cigarettes along with cannabis and alcohol, tailoring efforts toward specific subgroups of SMYAs. Bisexual women, in particular, may benefit from psychoeducation regarding the risks of polysubstance use and from support in managing difficult experiences and emotions. Emotion regulation skills may be a fruitful target for engaging in harmful patterns of polysubstance use to cope with discrimination (Vogel, Romm, & Berg, 2024, Vogel, Romm, & Berg, 2024). Importantly, bolstering individuals’ resilience is not a substitute for reducing discrimination in society; however, building resilience may help SMYAs maintain their health and well-being.