Polysubstance use patterns and trajectories in vocational students--a latent transition analysis

App-Based Addiction Prevention at German Vocational Schools: Implementation and Reach for a Cluster-Randomized Controlled Trial

This article examines the implementation, participation rates, and potential determinants of participation in the digital addiction prevention program "ready4life." A two-arm cluster-randomized trial recruited German vocational students via class-based strategies. Intervention group received 16 weeks of in-app coaching; the control group received health behavior information, with coaching offered after 12 months. Potential determinants of participation were analyzed based on class and individual characteristics. Out of 525 contacted schools, 35 participated, enrolling 376 classes. Implementation during the pandemic required flexible adjustments, with 49.7% of introductions conducted in person, 43.1% digitally via online streaming, and 7.2% received a video link via email. Despite challenges, 72.3% of the vocational students downloaded the app, and 46.7% gave informed consent. Participation rates were highest among (associate) professionals, vocational grammar school classes, classes introduced by females, younger individuals, members of the project team, and classes introduced face-to-face. Female gender, lower social competencies, lifetime cannabis use, higher problematic internet use, and higher perceived stress were associated with higher individual participation. The study highlights the importance of proactive outreach and personalized interventions for addiction prevention programs in vocational schools. While reached students aligned with the aims of the app, tailored recruitment strategies could enhance engagement among under-represented groups. The trial was registered in the German Clinical Trials Register (DRKS): DRKS00022328; registration date 09.10.2020.

Correlates of Stimulant Use among People Who Use Heroin Undergoing Treatment in Out-Patient Facilities in France, 2010-2020

Background: Polydrug use has been implicated in driving a "fourth wave" of the overdose crisis in North America, specifically through concurrent use of stimulants and opioids, especially fentanyl. In France, however, heroin has historically been and remains the easiest-to-access opioid, accounting for most drug treatment demand. Whether similar polydrug use is increasing in Western Europe remains understudied, despite severe health implications and potential inadequate public health responses.Methods: We take advantage of a nation-wide dataset containing information on all patients serviced in treatment centers in France from 2010 to 2020. We conduct Poisson regression to determine the main predictors of stimulant use among people who use heroin (PWUH) and opioids (PWUO) generally.Results: Heroin remains the primary opioid within drug treatment in France. A decreasing number of out-patients seeking treatment for heroin use has been accompanied by an increasing trend of stimulant use over time, most commonly with powder cocaine. Our results suggest a significant increase of crack cocaine use among the most vulnerable PWUH. Concurrent use of stimulants among PWUH was positively associated with use of alcohol, cannabis, unprescribed psychotropics and hallucinogens, and negatively with tobacco. Similar results were found for all in-treatment PWUO.Conclusions: Our results uncover heterogeneity in the profiles of PWUH that should be fully acknowledged to ensure better efficiency in substance use clinical practices and policy, while simultaneously drawing attention to trends in concurrent opioid-stimulant use outside North America. We advocate for an extension of the generalized risk framework and its implementation in prevention programs.

Examining Gender Differences in the Relationship Between School Bonding and Opioid Misuse Among Justice-Involved Adolescents

Justice-involved adolescents (JIAs) have an increased risk for opioid use disorder and overdose related to opioid misuse (OM). Consequences of untreated OM include recidivism and poor educational outcomes, which can be harsher for female JIA. Therefore, identifying relevant factors and settings that reduce the risk for OM is critical. Schools are a central institution in adolescent development. Drawing on social control theory, JIA with higher levels of school bonding was hypothesized to attenuate risk for OM. Cross-sectional data on 79,960 JIA from the Florida Department of Juvenile Justice were examined. Multivariate and stratified logistic regression analyses were employed. On average, for every one-unit increase in school bonding, JIA had 22%, female JIA had 23%, and male JIA had 22% lower odds of OM. Results suggest school bonding and the school context should be considered in treatment and how this setting may impact OM intervention outcomes among JIA.

Latent Classes of Substance Use in Young Adults - A Systematic Review

Background: This systematic review provides an overview of studies on latent classes related to the substance use among young adults (18-25 years). Identifying these classes helps to detect high-risk groups, setting a base for selective prevention.Methods: This systematic literature review included peer-reviewed studies (published up to February, 2021) that identified latent classes and investigated predictors of latent classes relating to the use of marijuana, alcohol and/or other substances within samples of young adults.Results: Twenty studies (sample sizes N = 171 to N = 21945) met the inclusion criteria. 14 studies identified 'low-level engagers', 'light alcohol and tobacco use', 'heavy alcohol and tobacco use' and 'heavy use/polysubstance use' classes. Four studies differentiated within the 'heavy/polysubstance' class and found 'traditional clubdrugs', 'hallucinogens' and 'wide-range illicit drugs' classes. Male gender and white race predicted membership of the 'heavy use/polysubstance use' class consistently across studies. Other predictors of polysubstance use that were consistent across studies were peer substance use, depressive symptoms, parental drinking and participating in an honor society.Conclusions: The investigated predictors of class membership provide insight into social settings and characteristics that predict heavy use or polysubstance use. They can contribute to the development of effective prevention interventions by allowing for a more targeted approach.

Associations between Longitudinal Patterns of Substance Use and Anxiety and Depression Symptoms among a Sample of Canadian Secondary School Students

The objective of this study is to examine the longitudinal associations between latent classes of substance use and anxiety and depression scores among youth who use substances. This study uses data from three waves (Wave 1: 2017/18, Wave 2: 2018/19, and Wave 3: 2019/20) of the COMPASS study. Students in grades 9 and 10 who reported substance use at baseline (n = 738) report their substance use (alcohol, cannabis, cigarettes, and e-cigarettes) and anxiety and depression symptoms at each wave. A Repeated Measures Latent Class Analysis (RMLCA) is used to determine substance use classes, and mixed models are used to examine the associations between substance use classes and anxiety and depression. We identify three classes of substance use: (1) occasional alcohol and e-cigarette use, (2) escalating poly-substance use, and (3) consistent poly-substance use. After controlling for relevant covariates, consistent poly-substance use is associated with depression (Female OR: 1.24 [95%CI: 0.46, 2.02]; Male OR 1.13 [95%CI: 0.38, 1.87]) but not anxiety. Escalating poly-substance use is associated with depression among males (OR 0.72 [95%CI: 0.10, 1.33]). These findings should be taken into consideration when creating prevention programming and treatment strategies for adolescents. Substance use programming should be comprehensive, consider multiple substances, and be cognizant of symptoms of mental illness, particularly depression.

Subpopulations of Addictive Behaviors in Different Sample Types and Their Relationships with Gender, Personality, and Well-Being: Latent Profile vs. Latent Class Analysis

BACKGROUND

Relatively strong theoretical assumptions and previous studies concerning co-occurring addictive behaviors suggest a subpopulation representing general proclivity to behavioral addictions (BAs), and there are gender-specific subpopulations. This study aimed to compare latent profile analysis (LPA) and latent class analysis (LCA) as the methods of investigating different clusters of BAs in the general student population and among students positively screened for at least one BA. Participants and procedure: Analyses of six BAs (study, shopping, gaming, Facebook, pornography, and food) and their potential antecedents (personality) and consequences (well-being) were conducted on a full sample of Polish undergraduate students (N = 1182) and a subsample (n = 327) of students including individuals fulfilling cutoff for at least one BA.

RESULTS

LPA on the subsample mostly replicated the previous four profiles found in the full sample. However, LCA on a full sample did not replicate previous findings using LPA and showed only two classes: those with relatively high probabilities on all BAs and low probabilities. LCA on the subsample conflated profiles identified with LPA and classes found with LCA in the full sample.

CONCLUSIONS

LCA on dichotomized scores (screened positively vs. negatively) were less effective in identifying clear patterns of interrelationships between BAs based on relatively strong theoretical assumptions and found in previous research. BAs can be investigated on the whole spectrum of behavior, and person-centered analyses might be more useful when they are based on continuous scores. This paper provides more detailed analyses of the four basic clusters of BAs, prevalence, and co-occurrence of particular BAs within and between them, their gender and personality risk factors, relationships to well-being, and their interrelationships as emerging from the results of this and previous studies.

Clustering of multiple health-risk factors among vocational education students: a latent class analysis

Physical and mental health risks often commence during young adulthood. Vocational education institutions are an ideal setting for understanding how health-risks cluster together in students to develop holistic multiple health-risk interventions. This is the first study to examine clustering of tobacco smoking, fruit intake, vegetable intake, alcohol consumption, physical inactivity, overweight/obesity, depression, and anxiety in vocational education students and the socio-demographic characteristics associated with cluster membership. A cross-sectional survey with vocational education students (n = 1134, mean age = 24.3 years) in New South Wales, Australia. Latent class analysis identified clusters and latent class regression examined characteristics associated with clusters. Four clusters were identified. All clusters had moderate inadequate fruit intake and moderate overweight/obesity. Cluster 1 (13% of sample) had "high anxiety, high inadequate vegetable intake, low tobacco, and low alcohol use." Cluster 2 (16% of sample) had "high tobacco smoking, high alcohol use, high anxiety, high depression, and high inadequate vegetable intake." Cluster 3 (52% of sample) had "high risky alcohol use, high inadequate vegetable intake, low depression, low anxiety, low tobacco smoking, and low physical inactivity." Cluster 4 (19% of sample) was a "lower risk cluster with high inadequate vegetable intake." Compared to cluster 4, 16-25-year-olds and those experiencing financial stress were more likely to belong to clusters 1, 2, and 3. Interventions for vocational education students should address fruit and vegetable intake and overweight/obesity and recognize that tobacco use and risky alcohol use sometimes occurs in the context of mental health issues.

Multiple Health Risk Factors in Vocational Education Students: A Systematic Review

Health risk factors such as tobacco smoking, inadequate fruit intake, inadequate vegetable intake, risky alcohol consumption, physical inactivity, obesity, anxiety and depression often commence during adolescence and young adulthood. Vocational education institutions enrol many students in these age groups making them an important setting for addressing multiple health risk factors. This systematic review examined (i) co-occurrence of health risk factors, (ii) clustering of health risk factors, and (iii) socio-demographic characteristics associated with co-occurrence and/or clusters of health risks among vocational education students. MEDLINE, PsycINFO, EMBASE, CINAHL and Scopus were searched to identify eligible studies published by 30 June 2020. Two reviewers independently extracted data and assessed methodological quality using the National Heart, Lung and Blood Institute Quality Assessment Tool. Five studies assessed co-occurrence and three studies clustering of health risks. Co-occurrence of health risk factors ranged from 29–98% and clustering of alcohol use and tobacco smoking was commonly reported. The findings were mixed about whether gender and age were associated with co-occurrence or clustering of health risks. There is limited evidence examining co-occurrence and clustering of health risk factors in vocational education students. Comprehensive assessment of how all these health risks co-occur or cluster in vocational education students is required.

Uptake of Proactively Offered Online and Telephone Support Services Targeting Multiple Health Risk Behaviors Among Vocational Education Students: Process Evaluation of a Cluster Randomized Controlled Trial

Background

A high proportion of vocational education students smoke tobacco, have inadequate nutrition (ie, low fruit and vegetable intake), drink alcohol at risky levels, or are physically inactive. The extent to which vocational education students will sign up for proactively offered online and telephone support services for multiple health risk behaviors is unknown.

Objective

The aim of this study is to examine the uptake of proactively offered online and telephone support services for smoking, nutrition, alcohol consumption, and physical activity risk behaviors, individually and in combination, among vocational education students in the Technical and Further Education (TAFE) setting. The characteristics associated with the uptake of online or telephone services for smoking, nutrition, alcohol consumption, and physical activity risk behaviors were also examined.

Methods

Vocational education students enrolled in a TAFE class in New South Wales, Australia, which ran for 6 months or more, were recruited to participate in a cluster randomized controlled trial from May 2018 to May 2019. In the intervention arm, participants who did not meet the Australian health guidelines for each of the smoking, nutrition, alcohol consumption, and physical activity risk behaviors were provided electronic feedback and proactively offered online and telephone support services. Uptake of support was measured by whether participants signed up for the online and telephone services they were offered.

Results

Vocational education students (N=551; mean age 25.7 years, SD 11.1; 310/551, 56.3% male) were recruited into the intervention arm. Uptake of the proactive offer of either online or telephone services was 14.5% (59/406) for fruit and vegetables, 12.7% (29/228) for physical activity, 6.8% (13/191) for smoking, and 5.5% (18/327) for alcohol use. Uptake of any online or telephone service for at least two health behaviors was 5.8% (22/377). Participants who were employed (odds ratio [OR] 0.10, 95% CI 0.01-0.72) and reported not being anxious (OR 0.11, 95% CI 0.02-0.71) had smaller odds of signing up for online or telephone services for smoking, whereas participants who reported not being depressed had greater odds (OR 10.25, 95% CI 1.30-80.67). Participants who intended to change their physical activity in the next 30 days had greater odds (OR 4.01, 95% CI 1.33-12.07) of signing up for online or telephone services for physical activity. Employed participants had smaller odds (OR 0.18, 95% CI 0.06-0.56) of signing up for support services for at least two behaviors.

Conclusions

Although the uptake of proactively offered online and telephone support services is low, these rates appear to be higher than the self-initiated use of some of these services in the general population. Scaling up the proactive offer of online and telephone services may produce beneficial health outcomes.

Trial Registration

Australian New Zealand Clinical Trials Registry: ACTRN12618000723280; https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=375001.

Prevalence and Sociodemographic Determinants of Substance Use in Turkey

BACKGROUND

Substance use disorder is a serious public health problem. It is essential to know who is prone to substance use in order to adopt appropriate measures.

OBJECTIVES

This study aims to determine the use prevalence ratios of substance use (tobacco, alcohol, cannabis, cocaine, synthetic cannabinoids, ecstasy, and others) in a large-scale sample of a general population. It also intends to examine related sociodemographic factors.

METHODS

This study is based on a cross-sectional survey conducted with a nationally representative sample of 24,494 individuals in face-to-face interviews conducted by a trained team of 125 clinical psychologists.

RESULTS

Lifetime prevalence of single substance use and polysubstance use are 4.5 and 2.6%, respectively (nicotine and alcohol excluded). Age, gender, education level, and marital status are important sociodemographic determinants for other substance use. Similarly, smoking and alcohol consumption are important determinants for other substance use. The multinomial regression analysis results showed that compared with adults aged 39 years and older, early-emerging adults (aged 18-23 years), late-emerging adults (aged 24-29 years), and young adults (aged 30-39 years) are more likely to turn to single substance use and polysubstance use.

CONCLUSION

Tobacco, alcohol, and other substance use are serious health concerns in Turkey. Sociodemographic status is an important determinant of several aspects of tobacco, alcohol, and other substance use and, therefore, should be examined thoroughly to be able to develop effective protective and preventive strategies.

Examining Sex and Racial/Ethnic Differences in Co-use of Alcohol, Cannabis, and Cigarettes in a Community Sample of Adolescents

INTRODUCTION

Although adolescents often co-use alcohol, cigarettes, and cannabis, little is known about sex and racial/ethnic differences in the co-use of these substances. Therefore, this investigation examined sex and racial/ethnic differences in alcohol, cigarette, and cannabis co-use in a large and ethnically diverse group. Methods: Participants were drawn from a large, multi-site study of adolescents from three regions in the United States (N = 4,129; Mage=16.10 years, SD = 0.59; 51% female, 49% male; 37% Black, 37% Hispanic, 25% White). Participants were categorized into eight mutually exclusive groups based on their self-reported use of alcohol, cannabis, and cigarettes in the last 30 days. Results: Unadjusted multinomial logistic regression revealed that males were more likely than females to use cannabis-only and to co-use all three substances. Additionally, Black and Hispanic adolescents were more likely to use cannabis-only, while White adolescents were more likely than Black and Hispanic adolescents to co-use alcohol and cigarettes. After adjusting for other sociodemographic variables (age, household income, parental education, and parent marital status), males were more likely to use cannabis-only than females; White youth were more likely than Hispanic youth to use cigarettes only and co-use cigarettes and alcohol. White youth were more likely than Black youth to co-use alcohol and cigarettes and co-use all three substances. Discussion: These results indicate sex and racial/ethnic differences in substance co-use that were not explained by socioeconomic factors. Results of this work suggest potential strategies for targeted prevention efforts and underscore the importance of continued efforts to better understand patterns of alcohol and substance co-use.

Patterns of substance use before and after hospitalization among patients seen by an inpatient addiction consult service: A latent transition analysis

BACKGROUND AND AIMS

Polysubstance use is common and contributes to morbidity and mortality of hospitalized patients, and yet little is known about patterns of substance use among hospitalized patients, or how an addiction consult service (ACS) might impact polysubstance use after discharge. The objective of this study was to identify patterns of substance use at admission and after discharge among hospitalized patients with substance use disorders who saw an ACS.

DESIGN

Prospective cohort study. We used latent transition analysis of substance use scores at the time of hospital admission and 30 to 90 days posthospitalization.

SETTING

Single, academic health center with an ACS in Portland, Oregon, from 2015 to 2018.

PARTICIPANTS/CASES

Patients were eligible if they received a consult to the inpatient ACS.

MEASUREMENTS

We used Addiction Severity Index-Lite scores to capture self-reported substance use at baseline and follow-up for heroin, other opioid, alcohol, amphetamine, and cocaine.

FINDINGS

From 2015 to 2018, 486 individuals consented to participate. More than half of patients used more than one substance at baseline. Of those reporting any baseline opioid use, nearly three-quarters (n=187, 69.5%) had polysubstance use in the previous 30 days, including alcohol (n=80, 29.7%), cocaine (n=25, 9.3%), or amphetamine use (n=142, 52.8%). We identified three patterns of substance use at baseline: 1) alcohol use dominant, 2) polysubstance use dominant, and 3) heroin and other opioid use dominant. Patients transitioned along five trajectories to three different follow-up profiles that showed lower endorsement of all substances used. Slightly more than 40% (40.1%) of patients newly endorsed abstinence of at least one substance at follow-up.

CONCLUSIONS

Polysubstance use is common in hospitalized patients with substance use disorders and identifying patterns of polysubstance use can guide clinical management. Hospital providers should prepare to manage polysubstance use during hospitalization and hospitals should broaden care beyond interventions for opioid use disorder.

Exploring gender differences in the longitudinal association between bullying and risk behaviours with Body Mass Index among COMPASS youth in Canada

The purpose of this study was to identify gender differences in the association between bullying and Body Mass Index (BMI) longitudinally. Longitudinal data (2013-2015) from 4510 youth (Ontario, Canada) were used to model BMI with consecutive bullying status prospectively, adjusting for previously identified gender-specific health risk behaviour latent classes. To assess for gender differences, these mixed-effects models were stratified by gender. Youth who were victims of bullying (VoB) were more active, engaged in more substance use and reported higher BMI than their non-victim of bullying (NVoB) peers. The gender-specific mixed-models showed that there are gender differences in the association between bullying and BMI. Among females, repeated bullying was associated with higher odds of having overweight/obesity [by 51% (95% C.I. = 1.03, 2.23)] at follow-up. Among male youth, being a VoB at the previous wave only, was associated with higher odds of having overweight/obesity [by 60% (95% C.I. = 1.11, 2.29)] at follow-up. In contrast with previous literature that measured BMI during adulthood (i.e., years after school victimization), our study adds a unique contribution to the literature that across one year (while youth are still in secondary school), bullying is associated with higher odds of weight status and BMI among female and male youth. Since this increase occurs during secondary school, school-based programs aimed at decreasing youth bullying behaviours and addressing increases in BMI before youth leave school are of paramount importance.

Gender differences in the longitudinal association between multilevel latent classes of chronic disease risk behaviours and body mass index in adolescents

INTRODUCTION

Few studies have assessed the relationship between chronic disease risk behaviours and body mass index (BMI) in a longitudinal, sex/gender-specific context. This study used gender-specific analyses to assess the extent to which chronic disease risk behaviour latent classes are associated with BMI and weight status at follow-up.

METHODS

Longitudinal data from 4510 students in Grades 9 to 12, tracked from 2013- 2015, who participated in the COMPASS study were used to assess gender differences in the lagged association between previously determined latent classes (of physical activity and substance use) with BMI using multilevel mixed-effects models. Our multilevel regression models assessed the association between two latent classes, active experimenters and inactive non-using youth, with BMI when stratified by gender.

RESULTS

Male inactive non-substance-using youth were associated with a 0.29 higher continuous BMI (95% CI: 0.057, 0.53) and odds of overweight/obesity increased by 72% (OR = 1.72, 95% CI: 1.2, 2.4) for binary BMI at follow-up relative to active youth who experiment with substance use. No significant associations were detected in females.

CONCLUSION

Over time, physical activity has a protective role on BMI in male youth. Both substance use and physical inactivity should be addressed in obesity prevention efforts. Gender stratification in analyses is also important since females and males have different contributing factors to increases in BMI.

Latent classes of lifetime drug use disorder in national epidemiological survey on alcohol and related conditions - III

AIMS/BACKGROUND

People diagnosed with multiple drug use disorders are high-risk subpopulations, but changes in diagnostic classification and drug use prevalence mean patterning of drug use disorders has changed in the past decade. We analyzed comorbidity patterns of lifetime drug use disorder in a general population sample.

DESIGN

Using latent class analysis, we derived lifetime drug use disorder classes based on dichotomous indicators of sedative, cannabis, opioid, cocaine, stimulant, hallucinogen, inhalant/solvent, club drug, heroin, and other drug use disorders in the National Epidemiologic Survey on Alcohol and Related Conditions-III (n = 36,309). Multinomial models assessed associations between sociodemographic and clinical correlates and latent class status.

RESULTS

Four latent classes of lifetime substance use disorder were identified: A very low risk class, a class with high opioid, sedative and heroin comorbidity, a class based on cocaine and stimulant comorbidity, and class with high likelihood of multiple lifetime drug use disorders. All higher risk classes were associated with higher risk of lifetime personality disorder and mood disorder. Conduct disorder was also associated with higher risk, but level of risk varied by class. Opioid and sedative class was associated with higher odds of lifetime eating disorder diagnosis.

CONCLUSIONS

Comorbidity of drug use disorders is associated with a range of lifetime mental health disorder diagnoses. Unlike previous research, we did not identify a cannabis use class, possibly due to changes in diagnostic criteria and cannabis prevalence rates.

Age trends in alcohol use behavior patterns among U.S. adults ages 18-65

INTRODUCTION

Although much of the work on risky alcohol use behaviors, such as heavy drinking, focuses on adolescence and young adulthood, these behaviors are associated with negative health consequences across all ages. Existing studies on age trends have focused on a single alcohol use behavior across many ages, using methods such as time-varying effect modeling, or a single age period with many behaviors, using methods such as latent class analysis. This study integrates aspects of both modeling approaches to examine age trends in alcohol use behavior patterns across ages 18-65.

METHODS

Data from the National Epidemiologic Survey on Alcohol and Related Conditions-III were used to identify past-year alcohol use behavior patterns among a nationally representative sample of U.S. adults (n = 30,997; 51.1% women; 63.5% White Non-Hispanic) and flexibly estimate nonlinear trends in the prevalences of those patterns across ages 18-65.

RESULTS

Five patterns were identified: Non-Drinkers, Frequent Light Drinkers, Infrequent Heavy Episodic Drinkers, Frequent Heavy Episodic Drinkers, and Extreme Drinkers. Pattern prevalences were allowed to vary flexibly across the entire age range. Prevalences of the Infrequent Heavy Episodic and Extreme Drinkers peaked around ages 22-24, but peaked for Frequent Heavy Episodic Drinkers around age 49. Non-Drinkers were most prevalent across all ages except during the early 20 s when Extreme Drinkers were more prevalent. Around ages 24-30, the Non-, Frequent Light, and Extreme Drinkers were approximately equally prevalent.

CONCLUSIONS

The approach used here holds promise for understanding characteristics associated with behavior patterns at different ages and long-term age trends in complex behaviors.

Patterns of Polysubstance Use Among Non-Hispanic White and American Indian/Alaska Native Adolescents: An Exploratory Analysis

INTRODUCTION

The prevalence of polysubstance use is well described, but less is known about correlates and patterns of polysubstance use. Previous research characterized latent subgroups of substance users by the type substance used. Racial disparities in the prevalence of polysubstance use exist, particularly for American Indian/Alaska Native (AI/AN) populations. The objective of our study was to describe differences in patterns of polysubstance use between non-Hispanic white and AI/AN adolescents.

METHODS

We obtained data from the 2013 Youth Risk Behavior Survey (YRBS). We analyzed substance use patterns (cigarettes, alcohol, marijuana, cocaine, inhalants, heroin, methamphetamines, ecstasy, steroids, and injected drugs) separately among 375 AI/AN and 15,633 non-Hispanic white adolescents. We calculated pairwise correlations. Exploratory factor analysis identified latent factors of polysubstance use patterns.

RESULTS

The use of all substances by AI/AN adolescents was the same or higher than use by non-Hispanic white adolescents, particularly for cocaine, heroin, and steroids. We found strong correlations between use of heroin and injected drugs and between use of cocaine and ecstasy among both populations. We found a latent factor for cigarettes, alcohol, and marijuana and another factor for broad polysubstance use among both populations. We found a factor for steroids and injected drugs among AI/AN adolescents, a factor for cocaine and ecstasy among non-Hispanic white adolescents, and a unique factor for methamphetamines.

CONCLUSION

Differences in substance use patterns exist between AI/AN and non-Hispanic white adolescents, particularly for illegal drug use. If validated in future research, information on these differences could be used to inform tailored intervention programs aimed at preventing substance use.

Transitions in the use of multiple substances from adolescence to young adulthood

BACKGROUND

Research indicates that many adolescents frequently use multiple substances. This study examines stability and transitions in the use and co-use of multiple substances (cigarette, alcohol, marijuana, illicit drugs) from adolescence to young adulthood.

METHODS

Data were collected biennially from 662 youth in six assessments across ten years (2003-2013). We used latent class analysis (LCA) to classify youth by substances used at each wave and used latent transition analysis (LTA) to examine transition probabilities across waves.

RESULTS

At each wave, a three-class model best fit the data. Classes included a poly-use class, that had the highest probabilities of use among all substances, a co-use class, that had high probabilities of use of alcohol and marijuana, and an alcohol-dominate class that started with low probabilities of use among all substances but showed increasing probabilities of alcohol use, at later ages. LTA showed that the probability of remaining in the poly-use class was the most stable from one wave to the next, followed by the alcohol-dominate class, and the co-use class. The most transitions occurred for the co-use class, with more individuals transitioning to the poly-use class than to the alcohol-dominate class.

CONCLUSIONS

Strong stability among adolescent substance use classes was found between waves. Transitions were typically to classes using more substances, although, transitions to use fewer substances was evident for some individuals. Distinguishing stable and transitioning classes of substance use and co-use provides opportunities for prevention and intervention to disrupt high-risk use classes.

Assessing the longitudinal stability of latent classes of substance use among gay, bisexual, and other men who have sex with men

BACKGROUND

Association between substance use and HIV-risk among gay and bisexual men (GBM) is well documented. However, their substance use patterns are diverse, and it is unknown whether self-reported use patterns are stable over time.

METHODS

Sexually-active GBM, aged >16 years, were recruited in Metro Vancouver using respondent-driven sampling and followed across 5 study visits at six-month intervals (n = 449). To identify distinct patterns of substance use and their longitudinal stability, Latent Transition Analysis (LTA) was conducted for drugs reported by at least 30 participants. Intraclass correlation coefficients (ICC) quantified the stability of class assignments.

RESULTS

Six classes characterizing 'limited drug use' (i.e., low use of all drugs, except alcohol), 'conventional drug use' (i.e., use of alcohol, marijuana, and tobacco), 'club drug use' (i.e., use of alcohol, cocaine, and psychedelics), 'sex drug use' (i.e., use of alcohol, crystal meth, GHB, poppers, and erectile dysfunction drugs), 'street drug use' (i.e., use of alcohol and street opioids) and 'assorted drug use' (i.e., use of most drugs) were identified. Across five visits (2.5 years), 26.3% (n = 118/449) of GBM transitioned between classes. The prevalence of limited use trended upwards (Baseline:24.5%, Visit 5:28.3%, p < 0.0001) and assorted use trended downwards (13.4%-9.6%, p = 0.001). All classes had strong longitudinal stability (ICC > 0.97).

CONCLUSION

The stability of latent substance use patterns highlight the utility of these measures in identifying patterns of substance use among people who use drugs - potentially allowing for better assessment of these groups and interventions related to their health.

Patterns of the co-use of alcohol, marijuana, and emerging tobacco products in a national sample of young adults

BACKGROUND

Emerging tobacco product use is on the rise in young adults and has been linked to alcohol and marijuana use. Little is known about which patterns of alcohol, marijuana, and emerging tobacco product co-use are most popular in this age group.

OBJECTIVES

This study examined the prevalence of a broad spectrum of marijuana, alcohol, and tobacco co-use patterns across a variety of tobacco products in a national sample of young adults.

METHODS

Data were analyzed from a sub-set of 18-24 year olds (unweighted n = 3,940) from five waves of the Truth Initiative Young Adult Cohort, a national sample of 18-34 year olds. A user-generated statistical program in R was used to assess all possible patterns of past 30-day use of alcohol, marijuana, cigarettes, cigars, e-cigarettes, little cigars/cigarillos, hookah, and other tobacco (pipe, chew, dip, snus, dissolvables).

RESULTS

No past 30-day use of any substance emerged as the most popular pattern across all years (42%), followed by exclusive past 30-day alcohol use (31%), and past 30-day alcohol use with cigarettes (5%) or marijuana (4%). The popularity of exclusive marijuana use increased over time, but only 1% reported exclusive marijuana use without the combination of either alcohol or a tobacco product. E-cigarette use only emerged in combination with alcohol and was the least popular pattern of co-use relative to other patterns.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

Patterns stress the importance of alcohol among young people. Successful substance use prevention should focus on alcohol's co-use with a variety of substances of abuse, rather than focus on a single behavior. (Am J Addict 2016;25:634-640).