Young Adult Substance Research Articles

37.4 Substance-Use Pattern Changes During the COVID-19 Pandemic: Implications for Clinical Professionals

37.4 Substance-Use Pattern Changes During the COVID-19 Pandemic: Implications for Clinical Professionals

Young Adult Substance Use and Healthcare Use Associated With Screening, Brief Intervention and Referral to Treatment in Pediatric Primary Care

PurposeScreening, brief intervention, and referral to treatment (SBIRT) may impact future comorbidity and healthcare utilization among adolescents screening positive for substance use or mood problems. MethodsIn a randomized trial sample, we compared an SBIRT group to usual care for substance use, mental health, medical diagnoses, and healthcare utilization over 7 years postscreening. ResultsIn logistic regression models adjusting for patient characteristics, the SBIRT group had lower odds of any substance (Odds Ratio[OR] = 0.80, 95% Confidence Interval [CI] = 0.66–.98), alcohol (OR = 0.69, 95% CI = 0.51–0.94), any drug (OR = 0.73, 95% CI = 0.54–0.98), marijuana (OR = 0.70, 95% CI = 0.50–0.98), and tobacco (OR = 0.83, 95% CI = 0.69–1.00) diagnoses, and lower odds of any inpatient hospitalizations (OR = 0.59, 95% CI = 0.41–0.85) compared with usual care. Negative binomial models examining number of visits among adolescents with at least one visit of that type found that those in the SBIRT group had fewer primary care (incidence rate ratio[iRR] = 0.90, p < .05) and psychiatry (iRR = 0.64, p < .01) and more addiction medicine (iRR = 1.52, p < .01) visits over 7 years compared with usual care. In posthoc analyses, we found that among Hispanic patients, those in the SBIRT group had lower odds of any substance, any drug and marijuana use disorder diagnoses compared with usual care, and among Black/African American patients, those in the SBIRT group had lower odds of alcohol use disorder diagnoses compared with usual care. DiscussionBeneficial effects of adolescent SBIRT on substance use and healthcare utilization may persist into young adulthood.

Young Adult E-Cigarette and Combustible Tobacco Users Attitudes, Substance Use Behaviors, Mental Health, and Neurocognitive Performance.

Nicotine and tobacco product (NTP) use has escalated, largely due to the advent of e-cigarettes. The NTP administration method (i.e., combustible cigarette, e-cigarette) may be an important differentiator. We assessed young adult substance use history, nicotine attitudes, mental health, and neurocognition by the NTP use method. Emerging adults (16–22 year olds) were divided into combustible NTP users (Combustible+ = 79, had used any combustible NTP in the last 6 months), non-combustible users (E-Cig = 43, had used non-combustible NTP, in the past 6 months), and NTP Naïve (n = 79; had not used NTP in the past 6 months) based on past 6-month NTP use patterns. Participants completed self-report and objective neurocognition measures. Analysis of covariance assessed mental health and neurocognition by group, controlling for confounds and correcting for multiple comparisons. Nicotine groups reported more favorable attitudes toward combustible cigarette and e-cigarette use, with taste as the primary reason for e-cigarette use. Combustible+ reported more nicotine dependence and craving. Substance use differed by group, with Combustible+ using the most NTP, alcohol, and cannabis. Nicotine groups reported higher depression and stress symptoms; male Combustible+ reported higher depression symptoms than other same-gender groups. Groups did not differ on neurocognition, though cannabis use was associated with inaccurate emotional Stroop responses. Overall, research suggests that young adult combustible users are likely qualitatively different from non-combustible users. Understanding the unique characteristics related to NTP product use will help guide intervention and prevention development.

An empirical evaluation of alternative approaches to adjusting for attrition when analyzing longitudinal survey data on young adults' substance use trajectories.

ObjectivesLongitudinal survey data allow for the estimation of developmental trajectories of substance use from adolescence to young adulthood, but these estimates may be subject to attrition bias. Moreover, there is a lack of consensus regarding the most effective statistical methodology to adjust for sample selection and attrition bias when estimating these trajectories. Our objective is to develop specific recommendations regarding adjustment approaches for attrition in longitudinal surveys in practice.MethodsAnalyzing data from the national U.S. Monitoring the Future panel study following four cohorts of individuals from modal ages 18 to 29/30, we systematically compare alternative approaches to analyzing longitudinal data with a wide range of substance use outcomes, and examine the sensitivity of inferences regarding substance use prevalence and trajectories as a function of college attendance to the approach used.ResultsOur results show that analyzing all available observations in each wave, while simultaneously accounting for the correlations among repeated observations, sample selection, and attrition, is the most effective approach. The adjustment effects are pronounced in wave‐specific descriptive estimates but generally modest in covariate‐adjusted trajectory modeling.ConclusionsThe adjustments can refine the precision, and, to some extent, the implications of our findings regarding young adult substance use trajectories.

Measuring subjective alcohol effects in daily life using contemporary young adult language.

Young adults' subjective feelings of alcohol's effects are a key predictor of engagement in risky behavior such as deciding whether to drive after drinking. To best inform prevention messaging and tailor intervention techniques that target high-risk drinking, it is critical that our measurement best captures subjective feelings. Standard sliding scales (0-100 rating of, "how drunk do you feel?") may have some challenges with distinguishing between levels of subjective responses to alcohol. The current daily diary study compared the utility of the standard sliding scale to a newly developed sliding scale that uses contemporary, crowd-sourced language from young adults as evenly spaced anchors (slightly buzzed, tipsy/"happy," drunk, and wasted) along a continuum of subjective effects of alcohol. Participants were 154 young adult substance users (58% women) who completed up to 14 consecutive daily reports of their substance use behavior. The four-anchored sliding scale performed similarly well as the standard scale in predicting alcohol use outcomes while showing the advantages of recording higher mean values/standard deviations and demonstrating that participants used the anchors to denote varying degrees of subjective effects. Findings suggest that the four-anchored subjective alcohol effects sliding scale is a viable alternative to the standard scale. By providing evenly spaced anchors that reflect incremental differences in language young adults use to describe their subjective states, the proposed scale may provide a guide for participants to indicate how they feel after drinking and may better capture variability in alcohol's effects. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Heterogeneity in effects of parent-child separation on young-adult substance use disorder.

A large body of literature suggests that parent-child separation predicts child maladjustment. However, further advancement in methodology is needed to account for heterogeneity in types of separation. Additionally, given a lack of research examining different types of separation as predictors of offspring substance use, further research into this topic is warranted. The present study tested the relation between parent-child separation and young-adult substance use disorder (SUD), capturing heterogeneity in these effects based on group differences and measurement of separation. In a sample of 427 young adults from a larger longitudinal study oversampled for parental alcohol use disorder (AUD), effects of number and type of separations on SUD diagnosis were tested. Further, we explored whether these associations were moderated by gender, ethnicity, or parental AUD. Two underlying types of separation were found: parental health-related separation (i.e., parental death, hospitalization) and nonhealth-related separation (i.e., divorce, arrest). A higher sum of separations and greater nonhealth-related separation predicted higher odds of SUD. Greater health-related separation predicted lower odds of SUD. However, these effects were qualified by interactions with ethnicity and parental AUD. Although the vast majority of studies measure cumulative parent-child separation with sum scores, the present study demonstrates that measuring underlying "types" of cumulative separation also reveals important effects. Moreover, childhood separation is a significant risk factor for SUD. Future research on separation should implement methods to capture separation types and further account for potential effects of selection into separation types. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

A Longitudinal Examination of the Relationship between Religious Service Attendance and Young Adult Substance Use

Abstract Young adulthood is a time of increased substance use. To better understand the effects of potential protective factors, this study explores the relationship between four types of religious service attendance during emerging adulthood and six measures of young adult substance use. Study data were abstracted from waves I (time 1 [T1]) and IV (time 2 [T2]) of the National Longitudinal Study of Adolescent to Adult Health (Add Health) surveys (N = 14,800). Logistic regression was conducted to calculate the odds of using each substance with the results weighted to produce nationally representative estimates. Analysis revealed that service attendance was generally associated with a lower likelihood of lifetime and recent use across all measures examined at T2. Relative to the reference group (nonattenders at T1 and T2), the protective effects were largest for the consistent attendance group (attenders at T1 and T2), followed by the adult attendance group (nonattenders at T1, attenders at T2), and then the childhood attendance group (attenders at T1, nonattenders at T2). The results suggest that diverse attendance types may exert a protective influence on adult substance use. Practitioners might explore attendance options in clinical settings in a client-centered manner.

Have e-cigarettes created a new crop of young adult substance users? Overlap between e-cigarette, traditional cigarette, and alcohol use

ABSTRACT Background Electronic cigarette use has increased among U.S. young adults since the early 2000s, but it is unclear whether use overlaps with traditional substance use or has produced a new at-risk population. Our goal was to compare trends in use of different legal substances and examine the association between e-cigarette use, demographic factors, and the use of other substances. Methods Data from the nationally-representative 2016–2019 U.S. Behavioral Risk Factor Surveillance System (BRFSS) from adults aged 18–24 were used (N = 64,604). Results Over the study period, e-cigarette use increased significantly, but traditional cigarette smoking and alcohol consumption decreased. Those who had ever used e-cigarettes were significantly more likely to be single, White or Native American, and report high school being their highest level of education. The majority of current daily e-cigarette users reported never having smoked traditional cigarettes (62.3%), not being a current traditional cigarette smoker (75.9%), and not being a binge drinker (59.3%). Conclusions As young adult e-cigarette use has increased, users are largely individuals who are not otherwise engaging in legal substance use. Future studies should examine factors leading to uptake of e-cigarette use among young adults in order to address this growing public health concern.

Stress and Affect as Daily Risk Factors for Substance Use Patterns: an Application of Latent Class Analysis for Daily Diary Data.

At the population level, use of multiple substances (or "co-use") is prevalent in young adulthood and linked with increased risk for experiencing substance-related harms. Less understood is the heterogeneity of substance use behaviors within individuals and across days, as well as the proximal predictors of these daily use patterns. The present study applied latent class analysis to daily diary data to identify daily substance use patterns and compare day-level class membership based on day-level stress and positive and negative affect among a higher-risk sample of young adult substance users. Participants (n = 152) completed up to 13 daily assessments of stress, affect, and substance use behavior. Among substance use days, five classes of days were identified: cannabis (some alcohol; 43% of days), alcohol-only (26%), vaping (some alcohol, cannabis; 24%), stimulant + alcohol (some cannabis, vaping; 4%), and cigarette-only (3%) days. Days with lower levels of perceived stress were significantly more likely to be alcohol-only Days relative to being days characterized by cigarette use, cannabis use, or multiple drug combinations. Days with higher levels of stress and negative affect were more likely to be cigarette-only days relative to cannabis and vaping days. Study findings document the wide range of substance use and co-use behaviors exhibited among young adults in daily life and highlight the importance of considering risk factors that correspond to days of problematic use patterns.

Interplay between genetic risk and the parent environment in adolescence and substance use in young adulthood: A TRAILS study.

Many adolescents start using tobacco, alcohol, and cannabis. Genetic vulnerability, parent characteristics in young adolescence, and interaction (GxE) and correlation (rGE) between these factors could contribute to the development of substance use. Using prospective data from the TRacking Adolescent Individuals' Lives Survey (TRAILS; N = 1,645), we model latent parent characteristics in young adolescence to predict young adult substance use. Polygenic scores (PGS) are created based on genome-wide association studies (GWAS) for smoking, alcohol use, and cannabis use. Using structural equation modeling we model the direct, GxE, and rGE effects of parent factors and PGS on young adult smoking, alcohol use, and cannabis initiation. The PGS, parental involvement, parental substance use, and parent-child relationship quality predicted smoking. There was GxE such that the PGS amplified the effect of parental substance use on smoking. There was rGE between all parent factors and the smoking PGS. Alcohol use was not predicted by genetic or parent factors, nor by interplay. Cannabis initiation was predicted by the PGS and parental substance use, but there was no GxE or rGE. Genetic risk and parent factors are important predictors of substance use and show GxE and rGE in smoking. These findings can act as a starting point for identifying people at risk.

Analyzing Twitter Chatter About Tobacco Use Within Intoxication-related Contexts of Alcohol Use: "Can Someone Tell Me Why Nicotine is So Fire When You're Drunk?"

Alcohol and tobacco are commonly used together. Social influences within online social networking platforms contribute to youth and young adult substance use behaviors. This study used a sample of alcohol- and tobacco-related tweets to evaluate: (1) sentiment toward co-use of alcohol and tobacco, (2) increased susceptibility to tobacco use when consuming alcohol, and (3) the role of alcohol in contributing to a failed attempt to quit tobacco use. Data were collected from the Twitter API from January 1, 2019 through December 31, 2019 using tobacco-related keywords (e.g., vape, ecig, smoking, juul*) and alcohol-related filters (e.g., drunk, blackout*). A total of 78,235 tweets were collected, from which a random subsample (n = 1,564) was drawn for coding. Cohen's Kappa values ranged from 0.66 to 0.99. Most tweets were pro co-use of alcohol and tobacco (75%). One of every ten tweets reported increased susceptibility to tobacco use when intoxicated. Non-regular tobacco users reported cravings for and tobacco use when consuming alcohol despite disliking tobacco use factors such as the taste, smell, and/or negative health effects. Regular tobacco users reported using markedly higher quantities of tobacco when intoxicated. Individuals discussed the role of alcohol undermining tobacco cessation attempts less often (2.0%), though some who had quit smoking for prolonged periods of time reported reinitiating tobacco use during acute intoxication episodes. Tobacco cessation interventions may benefit from including alcohol-focused components designed to educate participants about the association between increased susceptibility to tobacco use when consuming alcohol and the role of alcohol in undermining tobacco cessation attempts. Sentiment toward co-use of alcohol and tobacco on Twitter is largely positive. Individuals reported regret about using tobacco, or using more than intended, when intoxicated. Those who had quit smoking or vaping for prolonged periods of time reported reinitiating tobacco use when consuming alcohol. While social media-based tobacco cessation interventions like the Truth Initiative's "Ditch the Juul" campaign demonstrate potential to change tobacco use behaviors, these campaigns may benefit from including alcohol-focused components designed to educate participants about the association between increased susceptibility to tobacco use when consuming alcohol and the role of alcohol in undermining tobacco cessation attempts.

Supplemental Material for Heterogeneity in Effects of Parent–Child Separation on Young–Adult Substance Use Disorder

Supplemental Material for Heterogeneity in Effects of Parent–Child Separation on Young–Adult Substance Use Disorder

Changes in young adult substance use during COVID-19 as a function of ACEs, depression, prior substance use and resilience

Background: Given the potential for increased substance use during COVID-19, we examined (1) young adults’ changes in cigarette, e-cigarette, marijuana, and alcohol use from pre- to during COVID-19; and (2) related risk/protective factors. These findings could inform intervention efforts aimed at curbing increases in substance use during periods of societal stress. Methods: We analyzed Wave 3 (W3; September–December 2019) and Wave 4 (W4; March–May 2020) from the Vape shop Advertising, Place characteristics and Effects Surveillance (VAPES), a 2-year, five-wave longitudinal study of young adults across six metropolitan areas. We examined risk/protective factors (i.e. adverse childhood experiences [ACEs], depressive symptoms, resilience) in relation to changes in past 30-day substance use frequency. Results: In this sample (N = 1084, M age=24.76, SD = 4.70; 51.8% female; 73.6% White; 12.5% Hispanic), W3/W4 past 30-day use prevalence was: 29.1% cigarettes (19.4% increased/26.4% decreased), 36.5% e-cigarettes (23.2% increased/28.6% decreased), 49.4% marijuana (27.2% increased/21.2% decreased), and 84.8% alcohol (32.9% increased/20.7% decreased). Multivariate regressions indicated that, greater increases were predicted by: for e-cigarettes, greater ACEs; and for alcohol, greater depression. Among those with low resilience, predictors included: for e-cigarettes, greater depression; and for marijuana, greater ACEs. Conclusions: Interventions to reduce substance use during societal stressors should target both risk and protective factors, particularly resilience.

Intoxicated driving and riding with impaired drivers: Comparing days with alcohol, marijuana, and simultaneous use

BackgroundYoung adults who engage in simultaneous alcohol and marijuana (SAM) use may be more likely to engage in unsafe behaviors including riding with impaired drivers and driving after alcohol and/or marijuana use. MethodsYoung adult SAM users (N = 408) self-reported their behavior for five 14-day bursts, yielding daily-level responses on a total of 14,675 substance use days. Adjusted odds ratios (AOR) estimated the likelihood of riding with an impaired driver and of driving after use on SAM use days compared to alcohol- or marijuana-only use days. ResultsMore frequent SAM users were more likely to ride with an impaired driver and to drive after use than less frequent SAM users (between-persons). On SAM use days, there were greater odds of riding with an impaired driver, compared to alcohol-only days (AOR = 1.28) and marijuana-only days (AOR = 2.22), and of driving after use, compared to marijuana-only days (AOR = 1.25). Driving after use was more likely on days with non-simultaneous alcohol and marijuana use compared to SAM use (AOR = 1.59). ConclusionsRiding with an impaired driver is common among young adult substance users, and more likely following simultaneous use of alcohol and marijuana compared to other types of alcohol and marijuana use. Driving after use is more likely after SAM use than marijuana-only use days, but most likely on days when both alcohol and marijuana were used but not simultaneously. Future research on situation-level predictors of riding and driving-related risks among young adults is warranted.

Adult Gambling Problems and Histories of Mental Health and Substance Use: Findings from a Prospective Multi-Wave Australian Cohort Study.

Little is known about the cumulative effect of adolescent and young adult mental health difficulties and substance use problems on gambling behaviour in adulthood. We use data from one of Australia’s longest running studies of social and emotional development to examine the extent to which: (1) mental health symptoms (depressive and anxiety symptoms) and substance use (weekly binge drinking, tobacco, and cannabis use) from adolescence (13–18 years) into young adulthood (19–28 years) predict gambling problems in adulthood (31–32 years); and (2) risk relationships differ by sex. Analyses were based on responses from 1365 adolescent and young adult participants, spanning seven waves of data collection (1998–2014). Persistent adolescent to young adult binge drinking, tobacco use and cannabis use predicted gambling at age 31–32 years (OR = 2.30–3.42). Binge drinking and tobacco use in young adulthood also predicted gambling at age 31–32 years (OR = 2.04–2.54). Prior mental health symptoms were not associated with gambling and no risk relationships differed by sex. Findings suggest that gambling problems in adulthood may be related to the earlier development of other addictive behaviours, and that interventions targeting substance use from adolescence to young adulthood may confer additional gains in preventing later gambling behaviours.

Adolescent emotional disorder symptoms and transdiagnostic vulnerabilities as predictors of young adult substance use during the COVID-19 pandemic: mediation by substance-related coping behaviors

ABSTRACT The COVID-19 pandemic presents unique stressors (e.g. social isolation) that may increase substance use risk among young adults with a history of emotional disturbance. This study examined whether emotional disorder symptoms and transdiagnostic vulnerabilities during adolescence predicted young adult substance use during COVID-19, and whether using substances to cope with the pandemic’s social conditions mediated these associations. Adolescents (N = 2,120) completed baseline surveys assessing transdiagnostic emotional vulnerabilities (anhedonia, distress intolerance, anxiety sensitivity, negative urgency) and symptoms (major depression[MD], generalized anxiety[GAD], panic disorder[PD], social phobia[SP], obsessive-compulsive disorder[OCD]) in adolescence (September–December 2016; M[SD] age = 17.45[0.38]). At follow-up (May–August 2020; M[SD] age = 21.16[0.39]), past 30-day substance use and using substances to cope with social isolation during the pandemic were reported. Adjusted models showed that baseline distress intolerance, anxiety sensitivity, negative urgency, and MD symptoms each significantly predicted higher number of past-month single-substance using days and number of substances used at follow-up (βs = 0.04–0.06). In each case, associations were mediated by tendency to use substances to cope with the pandemic (βindirect range: 0.028–0.061). To mitigate disproportionate escalation of substance use in young adults with a history of certain types of emotional disturbance, interventions promoting healthy coping strategies to deal with the pandemic’s social conditions warrant consideration.

Where is the Family in Young Adult Substance Use Treatment? The Case for Systemic Family Therapy for Young Adults with Substance Use Disorders.

Despite the prevalence of SUDs, many individuals remain untreated (Grant et al., JAMA Psychiatry, 73(1), 39-45, 2016). Substance use disorders (SUDs) in young adults present unique challenges and stressors to parents of these individuals (D’Aniello et al., American Journal of Family Therapy, 2020; Kaur et al., International Journal of Community Medicine and Public Health, 5(6), 2380-2383, 2018; Shumway et al., Alcoholism Treatment Quarterly, 37(1), 75-98, 2019). Parents and caregivers often facilitate their children’s care and provide pragmatic and emotional support to their children; this high level of care is challenging to maintain, as with any chronic, relapsing condition. In the case of SUDs, the challenges caregivers face may be exacerbated by the stigma and the blame associated with parents in the development and maintenance of children’s SUDs, and the strains that come with navigating barriers related to accessing treatment in the USA. Estimates suggest that healthcare spending for substance use treatment is relatively low and few utilize therapeutic family treatment. This disconnect between widespread SUD prevalence, and service underutilization, indicates that families who need treatment are not accessing it. The present paper synthesizes the extant literature on the role of family members in SUD treatment, as families are a primary context of care for their children’s treatment across many chronic, relapsing conditions. Finally, we identify the utility of family therapy in addressing family member’s unique needs related to their loved one with a SUD, in the family and in a treatment context.

Prevalence of Young Adult Vaping, Substance Vaped, and Purchase Location Across Five Categories of Vaping Devices.

The rapidly evolving landscape of vaping devices has complicated analyses of use patterns among youth and young adults. The current study describes the prevalence of use, substances vaped, and purchasing behaviors across five different vaping device categories. Participants (n = 2505; mean age = 19.2, SD = 0.46) from a cohort in the Los Angeles area completed web-based surveys from June 2018 to October 2019. For each of four device type categories depicted via digital images (any pod-style vape, cigalike, box-mod, vape pen) and for JUUL specifically, participants reported ever and past 30-day use, substance vaped (mostly nicotine, nicotine and tetrahydrocannabinol [THC], mostly THC, neither), ownership of device (yes/no), where they obtained that device (eg, purchased themselves, from a friend), and if purchased, purchase location (eg, vape shop, online). Overall, 44.9% reported ever use, and 26.2% reported past 30-day use of at least one of the devices. The prevalence of past 30-day use was highest for pod-style vapes (any pod = 17.0%; JUUL = 15.1%). Among respondents who reported ever owning any device (n = 643 [25.7%]), 59.9% reported purchasing the device themselves, despite not being of legal purchasing age (15.4% of total sample); across all device types, products were most often purchased in vape shops or online. Across all devices, the prevalence of self-purchase of vaping devices among underage young adults in the Los Angeles area was high, and most were purchased from a vape shop or online. Tobacco control policies to prevent underage purchase of tobacco products-particularly among never smokers-are needed. A high proportion of underage young adults reported owning their own vaping device and having purchased it themselves from a vape shop or online. Stronger tobacco control policies and better enforcement efforts are needed to successfully prevent underage purchase of tobacco products.

Risks versus consequences of adolescent and young adult substance use: A focus on executive control.

This review examines the role of executive control processes in the liability for substance misuse and whether substance use, once initiated, leads to subsequent decrements as proposed by neurotoxicity models of substance use disorder (SUD). As indicated by a number of recent meta-analyses, executive control processes, which include working memory, cognitive flexibility and numerous aspects of attentional, behavioral and emotional control, are impaired in the context of active SUD. Longitudinal studies of behaviorally disinhibited children, individuals with familial risks for SUD, and twins within whom genetic versus environmental influences on behavior can be modeled robustly indicate that relatively poor control is a vulnerability factor for early substance use initiation, binge patterns of use, and subsequent SUD. Evidence of further declines in executive control, once substance use is initiated, is mixed, although a growing number of neuroimaging studies indicate that frontostriatal, frontolimbic, and frontocerebellar systems are altered as a consequence of use. Together these patterns suggest strategies for identifying children and adolescents at high risk for SUD, avenues through which substance-related neurotoxicities can be more reliably detected, and the need to structure prevention efforts in a manner that is developmentally appropriate and perhaps personalized to individual vulnerabilities.

Differences in substance use by sexual orientation and gender among Jewish young adults in Israel

BackgroundThis study focuses on sexual orientation and gender-based differences among Israeli young adult substance use behaviors. In addition, it evaluates young adult perception of substance use and acceptance of substances use by close friends.MethodsWe conducted a cross-sectional study. A self-reported anonymous questionnaire was distributed to a convenience sample of 496 young-adults (age: M = 23.14, SD = 2.48), which included 126 heterosexual males, 128 heterosexual females, 131 gay men, and 111 lesbians.ResultsThis study revealed significant sexual orientation and gender differences in all outcomes examined. Significant substance usage differences were found for same-sex orientation as 52% reported cannabis use and 24% reported using other illegal substances during the past 12 months compared to 34 and 6% (respectively) among heterosexuals. Significant gender differences were found, as male participants reported 50% cannabis use and 19% reported other illegal substance use in the past 12 months compared to 35 and 11% (respectively) among females.Additionally, compared with heterosexuals, gay men and lesbians perceived/assessed significantly higher substance usage rates among their close friends and higher levels of substance use acceptance by close friends. Regression models indicated the important role of respondent perceived and acceptance of substance use among close friends.Binge drinking, cannabis use, and other illegal substance use were positively associated with participants’ perceived substance use and substance use acceptance level by close friends, after controlling for gender, sexual orientation, age, and level of education.ConclusionsClose friends and community norms can play an important role in shaping substance usage among young adults, especially among gay men and lesbians. The results of the current study highlight the need for developing prevention and harm reduction drug policies for Israeli young adults, especially for gay men and lesbians. Interventions should also focus on young adult peers and community norms related to substance use by professionals in educational, policy-making, and therapeutic contexts.