This study was embedded within a larger longitudinal birth-cohort study and therefore limited by attrition. It is possible that mothers who chose to participate in the study and to continue for multiple assessments may have differed from those who did not, although retention since age 9 was around 95%. Given limitations, results should be replicated among diverse populations, as well as other samples of Mexican-origin youth. Lastly, the study was limited to youth who had no gang involvement because of risk for violent responses to the TSST. This criterion may have attenuated associations, as gang members often show greater substance use . Substance use disorders affect more than 20 million individuals in the United States annually, increasing risk for psychiatric disorders, chronic diseases, and disruptions to social, family, and work lives . SUD prevalence peaks during young adulthood , with co-occurrence of multiple SUDs also common during this time period, which increases clinical severity and complicates treatment . Previous research has established that, compared to completely heterosexual and cisgender individuals , sexual and gender minorities engage in greater substance use beginning in adolescence and extending throughout life .Even fewer have examined more serious SUD outcomes by sexual orientation or gender identity or have focused on SUDs during young adulthood . The present study addresses these gaps by examining associations between SGM statuses and past 12-month prevalence of SUDs in a community cohort of U.S. young adults. SGM disparities in SUDs persist because SGMs use substance to cope with SGM-related minority stressors,cannabis grow system including self-stigma and interpersonal and structural-level discrimination . Disparities may also be driven by differences in substance use norms within SGM communities . For example, research indicates that sexual minorities perceive greater availability of substances and have more tolerant use norms than do heterosexuals .

Additionally, gender minority youth may perceive less risk associated with substance use than cisgender youth .Research has found persistent variation in SUD risk by sex. In the general population, men experience single and co-occurring SUDs at higher levels than women . Among SMs, however, sex differences are typically reduced or even reversed, with greater sexual orientation disparities among adult women compared to men, and especially elevated rates among bisexual women . Nonetheless, studies have rarely tested whether sex modifies relationships between sexual orientation and SUDs by including interaction terms in statistical models. Prevalence of SUDs tends to peak around age 25 and declines with age . Research examining SUDs among SMs, however, suggests a slower agenormative decline . Rarely have researchers compared sexual orientation or gender identity disparities in SUDs among individuals older than 25 years with those in younger age groups. Knowledge of how the magnitude of sexual orientation and gender identity differences in SUDs vary by birth sex and age can help identify subgroups in need of interventions. Research on how gender identity is associated with SUD risk is severely lacking, with available studies using small, subgroup samples . Studies also frequently lack cisgender comparison groups, preventing quantification of gender identity differences. This study analyzed data from the longitudinal Growing Up Today Study when participants were aged 20-35 to estimate sexual orientation and gender identity differences in probable SUDs. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition criteria were used to assess past 12-month nicotine dependence, alcohol abuse/dependence, drug abuse/dependence, any SUD, and co-occurring multiple SUDs . Because research demonstrates sex differences in associations between sexual orientation and substance outcomes , we estimated statistical interactions between 1) sexual orientation and birth sex, and 2) gender identity and birth sex, and present birth-sex-stratified estimates.

We hypothesized that SGMs would be more likely than non-SGMs of their same birth sex to meet criteria for SUDs, and that sexual orientation differences would be larger among participants assigned female at birth compared to those assigned male. Additionally, we estimated statistical interactions between 1) sexual orientation and age, and 2) gender identity and age. We hypothesized that sexual orientation and gender identity differences in SUD risk would be larger in older versus younger periods. Among participants meeting criteria for a past 12-month drug use disorder, we examined associations of sexual orientation and gender identity with past 12-month specific drug use.Our study quantified sexual orientation and gender identity differences in SUD risk during young adulthood, when SUD prevalence in the general U.S. population is high . We examined SUDs based on DSM-IV criteria including nicotine dependence, alcohol abuse and dependence, drug abuse and dependence, and multiple co-occurring SUDs. Aligning with previous literature , we found that SM status was associated with greater odds of past 12-month SUDs among young adults assigned female, and to a lesser extent among those assigned male. Co-occurrence of 2 or more SUDs in the past 12-months was also more common among SMs compared CHs, aligning with previous studies of lifetime SUD co-occurrence . Contrary to our hypothesis, age-related declines in SUD prevalence were largely similar across sexual orientation and gender identity groups. This finding may be due, in part, to our sample age range and age periods compared in analysis . Previous studies have shown differential age-related declines in alcohol problems between SMs and heterosexuals and noted the largest sexual orientation differences in ages 40 or older . An analysis of representative U.S. data showed declines in the prevalence of tobacco and alcohol disorders among SMs between ages 26-35 but increases in prevalence between the mid-30s to mid-40s . We uniquely examined how GM status is related to risk for SUDs. This is an important contribution as studies assessing SUDs by gender identity are limited and typically focused on substance use instead of abuse . In contrast to findings related to sexual orientation, we did not find consistent evidence of greater prevalence of SUDs among GMs after accounting for sexual orientation in statistical models.This lack of evidence, however, should be interpreted with caution considering small numbers of GM participants in GUTS and previous evidence indicating their disproportionate substance use .

Additional studies quantifying associations between gender identity and SUDs are needed.Among the general population, more people assigned male at birth report probable SUDs than do people assigned female at birth . In contrast, we found SMs assigned female generally had similar or higher levels of SUDs compared to SMs assigned male, and sexual-orientation differences were larger in assigned females than assigned males. One reason is that comparisons between SM and CH women will yield relatively large effect sizes because CH women have the lowest levels of SUDs of all groups defined by sexual orientation and birth sex. Beyond this explanation, there is little insight into why SM women are at especially elevated risk, though some have proposed that SM women are at greater risk for minority-specific stressors and mood disorders, resulting in greater risk for SUDs .Among participants with a drug use disorder,marijuana grow system we found that some subgroups of SGMs had elevated odds of reporting use of certain drugs compared with CHs and cisgender participants. Studies examining sexual orientation or gender identity differences in drug use among individuals with drug use disorders are rare; however, cross-sectional studies with participants of the NSDUH found that SM adults were significantly more likely than heterosexuals to report past-year marijuana and other drug use . This indicates that SGMs may be more likely to use different substances than non-SGMs, which has implications for screening, intervention, and treatment . The DSM-IV defined separate criteria for substance abuse and dependence, whereas in the updated DSM-5, abuse and dependence are combined into a single SUD diagnosis . Studies comparing DSM-IV and DSM-5 SUD diagnostic criteria have shown increases , no differences , and decreases in prevalence. Increases in SUD prevalences under DSM-5 may relate to the inclusion of ³GLDJQRVWLF RUSKDQV´ in diagnoses² those who meet one or two DSM-IV criteria for dependence, but none for abuse . Nonetheless, concordance of DSM-IV and DSM-5 diagnoses are acceptable, with concordance increasing with severity , suggesting that our findings are likely similar to those resulting had we used DSM-5 criteria. Further research is needed to clarify this issue. GUTS participants are not representative of the U.S. population as they are children of registered nurses and predominantly non-Hispanic White. The prevalence of SUDs in GUTS, however, is comparable to same-aged participants of the NSDUH , as is the distribution of SGMs enrolled in GUTS compared to population-based studies . Additionally, GUTS participants were not enrolled based on their sexual orientation or gender identity. GUTS assessed sexual orientation with a single item tapping both identity and attraction. This limits direct comparisons between our findings and other studies assessing dimensions of sexual orientation separately because research indicates these dimensions have different associations with substance involvement . Further, despite the large sample size, we were limited in our ability to detect within group differences among SGMs. Despite these limitations, our study is strengthened by including multiple SGM subgroups, enabling examination of heterogeneous outcomes that may otherwise be obscured when combining SGM categories. Future research should include more diverse, nationally representative samples to enable examination of interactions between sexual orientation, gender identity, and other sociodemographic factors to further identify higher-risk SGM subgroups.

Among the general population, young adults with SUDs experience disproportionate economic and public health burdens and have low utilization of SUD treatment . For SGM young adults, these issues may be even more persistent, with one study finding that less than 4% of the 14-20% of SMs needing treatment actually accessing treatment . Specific barriers to treatment among SGMs include a lack of targeted interventions, differences in coping strategies and psychiatric comorbidities, discrimination within healthcare settings, lack of provider knowledge about SGM health needs, and lack of insurance . Consequently, increasing access to treatment alone may be insufficient to address SGM SUD disparities. Efforts should also focus on bolstering the provision of culturally tailored, SGM affirming treatment which promotes resilience, coping, and wellness. Further, given high co-morbidity with other mental disorders, interventions are needed which integrate psychological and SUD treatment .Methamphetamine dependence commonly accompanies HIV infection, typically because of behaviors during drug use that increase the risk of viral transmission . While each of these conditions by themselves often have negative effects on the individual’s cognition and functional behaviors, there is also evidence that the combined effect of HIV infection and heavy METH use may have additive effects, e.g., resulting in worse neuronal injury , compounded damage to frontostriatal circuits , and more profound neuropsychological impairment than either condition alone. Neuropsychological deficits, particularly those that are frontally-mediated, are thought to substantially impact everyday functional ability, i.e., the ability to engage in vital tasks of daily living . For people living with HIV, an added demand is adherence to an antiretroviral therapy regimen. Although HIV and METH dependence have each been associated with worse performance on tasks of everyday functioning , the combined effects of HIV infection and heavy drug use on the ability to carry out tasks of daily living have not been widely studied [but see ] but are important to understand given the high co-occurrence of these two conditions and the potential adverse implications for medication adherence and other important functional behaviors. Parsing the relationships among HIV illness, METH use characteristics, and everyday functioning may help inform treatment decisions. For example ART seems to reduce the severity of HIV-associated neurocognitive disorders , however some antiretroviral medications do appear to have neurotoxic effects . Furthermore, there are limitations in the operationalization of everyday functioning in previous investigations. Many studies of everyday functional ability, including those conducted in HIV and substance dependence have used self-report measures that ask the individual to rate how well they perform activities of daily living. We and others have proposed that reliance on self-report is problematic especially during the study of conditions with known cognitive impairment. Performance based functional measures, such as the UCSD Performance Based Skills Assessment , are useful in that they divide everyday function into specific components and have high reliability and validity , e.g., comprehension and planning abilities, financial skills, knowledge in use of transportation and managing the household, and the extent to which individuals can internalize and plan to take a complex daily regimen of medications.