The topography of multiple drug use among adolescent Australians: findings from the National Drug Strategy Household Survey

Suicidal Thoughts and Behaviors Among US Adolescents: The Cumulative Effects of Polysubstance Use Behaviors

Background: The linkage between substance use and youth suicidality is less developed due to the predominant focus on certain types of substances (e.g., alcohol consumption, prescription opioid misuse). This study examines polysubstance use and its mutual impact on suicidal thoughts and behaviors among US adolescents. Methods: Data from 2019 Youth Risk Behavior Survey were utilized. Associations between the concurrent use of five substances (cigarette, e-cigarette, alcohol, marijuana, and prescription opioid) and suicidality (suicidal thoughts, suicide plans, and suicide attempts) were measured by logistic regression models. The combined effect of polysubstance use on suicidality was further assessed by structural equation modeling. Results: About two in five (42.1%) adolescents used at least one type of substances in the past month and one in seven (13.5%) used three or more types concurrently (polysubstance use). Adolescents with polysubstance use behaviors were three to five times more likely to experience suicidal thoughts (OR=3.8, p < 0.05), make a suicide plan (OR=3.5, p < 0.05), or attempt suicide (OR=4.6, p < 0.05) than non-users. In the final structural model, polysubstance use and suicidality were significantly correlated with each other (β=0.37, p < 0.05). Collectively, polysubstance use explained about 14% of variance in youth suicidality. Conclusions: Polysubstance use shows a significant impact on youth suicidality. School-based health centers and educational programs are recommended to reduce substance use and suicidal behaviors among adolescents. Accessible mental health services and targeted treatments are needed for polysubstance users to mitigate their risk of suicide.

Birds of a Feather Get High Together: A Reconceptualization of the Social Bond with Latent Class Analysis and a Test with Different Forms of Drug Use

Social bond theory has received significant empirical support in examinations of drug use for decades. However, research utilizing the theory has often been fragmented and has not incorporated all four dimensions of the social bond. Additionally, much of this research has collapsed drug use into categories rather than examining specific forms of drug use. These concerns confuse the theoretical and practical insights that may be derived from such analyses. I utilize Monitoring the Future (2019) data to examine social bonding wholistically as latent classes in line with the concept of the social bond described by Hirschi (1969) and estimate the effect of the classes on specific forms of drug use. I find there are four distinct classes of social bonding among U.S. seniors most clearly differentiated by levels of attachment and commitment. Logistic regression results indicated different classes of social bonding were associated with different forms of drug use. I discuss the theoretical implications of the results and how they can be applied for criminal justice practitioners.

Polysubstance Use Is Positively Associated with Gaming Disorder Symptom Severity: A Latent Class Analytical Study

INTRODUCTION

The link between gaming disorder (GD) and substance use amongst adolescents is not clear. Some studies reported positive associations, whereas others suggested that alcohol and illicit drug use are not related to GD severity.

OBJECTIVES

The present study aimed to identify empirically based latent classes of alcohol and illicit drug use amongst adolescents and explore their associations with GD symptom severity and whether endorsement of specific criteria of GD is linked to the membership of latent classes of alcohol and illicit drug use.

METHODS

Data of the national sample of Hungarian adolescents from the Health Behaviour in School-aged Children survey (N = 2,768; females: 52.08%; mean age: 16.73 years) were analysed. Measures for frequency of alcohol and illicit drug use, gaming, GD symptom severity, and life satisfaction were included in the analyses.

RESULTS

Latent class analysis discriminated 4 subgroups of alcohol and illicit drug use: polysubstance users, high-risk alcohol users, moderate alcohol users, and infrequent substance users. Polysubstance users presented significantly higher levels of GD symptom severity and higher odds for endorsement of criteria of "giving up other activities" and "negative consequences."

CONCLUSIONS

Positive associations were shown between higher GD severity and the polysubstance using class. The roles of criteria of "giving up other activities" and "negative consequences" were highlighted in more severe substance use patterns. However, GD severity and criteria did not differ as a function of the level of alcohol use. These findings may imply common roots of GD and illicit drug use in adolescents.

Co-exposure of cocaine and cannabinoids and its association with select biological, behavioural and health outcomes: A systematic scoping review of multi-disciplinary studies

Cocaine use entails severe health- and social-related harms globally. Treatment options for cocaine dependence are highly limited. Benefits of cannabinoids for addiction have been documented, making it opportune to examine existing data on the possible outcomes associated with cannabinoids and cocaine co-use. We conducted a systematic scoping review following the PRISMA guidelines of peer-reviewed, English-language studies published from 2000 to 2021 in four databases (Medline, Web-of-Science, CINAHL Plus, and PsycInfo), assessing the co-exposure of cannabis/cannabinoids with cocaine on behavioural, biological or health outcomes. Both quantitative and qualitative, as well as humans and pre-clinical animals' studies (n=46) were included. Pre-clinical studies (n=19) showed mostly protective effects of cannabidiol (CBD) administration on animal models of addiction (e.g., cocaine-craving, -relapse, and -withdrawal) and cocaine-toxicity. Tetrahydrocannabinol (THC) had more inconsistent results, with both protective and counter-protective effects. Human studies (n=27) were more heterogeneous and assessed natural ongoing cannabis and cocaine use or dependence. Quantitative-based studies showed mostly enhanced harms in several outcomes (e.g., cocaine use, mental health); two available clinical trials found no effect upon CBD administration on cocaine-related treatment outcomes. Qualitative data-based studies reported cannabis use as a substitute for or to alleviate harms of crack-cocaine use. While pre-clinical studies suggest a potential of cannabinoids, especially CBD, to treat cocaine addiction, the few trials conducted in humans found no benefits. Cannabis co-use by cocaine users commonly presents a risk factor, entailing enhanced harms for users. More rigorous, controlled trials are still necessary to investigate cannabinoids' potential considering pre-clinical findings and reported benefits from specific drug users.

New psychoactives within polydrug use trajectories-evidence from a mixed-method longitudinal study

AIMS

To provide public health-related research evidence on types and usage patterns of new psychoactive substances (NPS), developmental pathways into NPS and decision-making factors for, and associated harms of, NPS use.

DESIGN

Three-phase mixed-methods design, including a latent class analysis (LCA) of the longitudinal Belfast Youth Development Study (BYDS), a narrative analysis of interviews with NPS users and a three-step approach manual method modelling using regressions to reveal classes of substance use and their associated predictors and outcomes.

SETTING

Northern Ireland.

PARTICIPANTS

A total of 2039 people who responded to the questions on 'ever use' of the drug variables included at wave 7 (aged 21 years) of the BYDS. Eighty-four narrative interviews with NPS users.

MEASUREMENTS

Categories of drug use identified by LCA. Predictors and outcomes included measures of family, partners, peers, substance use, school, delinquency and mental health.

FINDINGS

A four-class solution provided the best fit for the data: alcohol; alcohol and tobacco; alcohol, tobacco and cannabis; and polydrug (the latter including NPS). The qualitative analysis yielded a taxonomy that distinguished how NPS operate within a wider range of drug repertoires from experimental to problematic.

CONCLUSIONS

In Northern Ireland, new psychoactive substances appear to be a feature of broader polydrug use rather than a standalone class of drug use.

Apoptotic inducement of neuronal cells by codeine: possible role of disrupted redox state and caspase 3 signaling

Background

Codeine, a common drug of abuse, has been reported to induce organ damage; however, there are scanty available data on the effects of codeine on the brain.

Objective

Thus, we tested the hypothesis that redox dysregulation and inflammation of the brain induced by codeine exposure is 8-OHdG and/or caspase 3-dependent.

Methods

New Zealand White rabbits (Oryctolagus cuniculus) received vehicle (control; n = 7), low-dose codeine (4 mg/kg/day p.o; n = 6), or high-dose codeine (10 mg/kg/day p.o; n = 6) for six weeks. Body weight was checked before and after the study.

Results

Findings showed that codeine exposure resulted in redox dysregulation (evident by elevated MDA and H₂O₂ accompanied by reduced enzymatic antioxidant activities), elevated MPO activity, and distorted cytoarchitecture of the brain tissue. The observed codeine-induced redox imbalance and brain inflammation was accompanied by depletion of neuronal and purkinje cells, reduced AchE activity, and elevated 8-OHdG levels and caspase 3 activity.

Conclusions

The current study demonstrates that chronic codeine use induces oxido-inflammatory response and apoptosis of the brain tissue that is associated with neuronal and purkinje cells injury, and impaired AchE activity through 8-OHdG and/or caspase 3-dependent pathway.

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Codeine led to redox dysregulation and inflammation of the brain.

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This was accompanied by distorted cytoarchitecture of the brain.

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Codeine also caused depletion of neuronal and purkinje cells with reduced acetylcholinesterase activity.

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Codeine-induced brain injury was mediated by upregulation of 8-OHdG/caspase 3 signaling.

Opioid Misuse among Smokers with Chronic Pain: Relations with Substance Use and Mental Health

Opioid misuse is a significant public health concern with substantial medical, social, and economic costs. Cross cutting the personal and societal effects of this current crisis, opioid misuse is associated with poorer physical and mental health outcomes that impair function across numerous life domains. Importantly, opioid misuse disproportionately affects persons with chronic pain and individuals who smoke tobacco. Despite the higher risk for smokers with chronic pain to engage in opioid misuse, little work has examined how opioid misuse may be related to mental health problems, including other substance use, among this vulnerable group. The current study examined opioid misuse as a predictor of substance use and mental health problems among 187 (M_age = 39.02, SD = 9.94, 74.9% female) daily cigarette smokers with chronic pain who currently use opioids. Results indicated that opioid misuse is associated with greater tobacco (13% of variance), alcohol (27% of variance), and cannabis (22% of variance) problems, as well as anxiety (26% of variance) and depressive symptoms (26% of variance). These results highlight the potential importance of opioid misuse in terms of concurrent substance and mental health problems among smokers with chronic pain. Future work is needed to explicate directionality and temporal ordering in the observed relations.

Polysubstance use among adolescents in Malaysia: Findings from the National Health and Morbidity Survey 2017

BACKGROUND

Polysubstance use is defined as the use of more than one non-prescribed licit or illicit substance either concurrently or simultaneously. This study aimed to determine the prevalence of single substance users and polysubstance users and 'their associated factors among adolescents in Malaysia.

METHODS

This study was a secondary data analysis from the National Health and Morbidity Survey (NHMS) 2017, a cross-sectional survey conducted among Malaysian school-going adolescents aged 13 to 17. The NHMS utilised a two-stage stratified cluster sampling. Multivariate Multinomial Logistic Regression analysis was applied.

RESULTS

The overall prevalence of single substance use and polysubstance use among adolescents were 17.2% and 5.1% respectively. The multinomial model showed a higher likelihood of being single or polysubstance user among male (single user OR = 3.0, poly user OR = 4.6), others Bumiputeras vs Malay (single user OR = 1.7, poly user OR = 5.3), those who live with a single parent (single user OR = 1.2, poly user OR = 1.4), involved in truancy (single user OR = 1.7, poly user OR = 3.6) and being bullied (single user OR = 1.3, poly user OR = 3.4), those who had lack of peer support (single user OR = 1.3, poly user OR = 1.4), poor parental bonding (single user OR = 1.4, poly user OR = 1.8), depression (single user OR = 1.4, poly user OR = 3.2) and those who had no close friend (single user OR = 1.3, poly user OR = 2.7).

CONCLUSION

Our study highlighted multiple significant associated factors of single and polysubstance use among adolescents in Malaysia. This result can assist in the development of specific intervention and prevention programs targeting high-risk groups.

Clustering of health-related behaviours within children aged 11-16: a systematic review

OBJECTIVE

We aimed to systematically review and synthesise evidence on the clustering of a broad range of health-related behaviours amongst 11-16 year olds.

METHOD

A literature search was conducted in September 2019. Studies were included if they used cluster analysis, latent class analysis, prevalence odds ratios, principal component analysis or factor analysis, and considered at least three health-related behaviours of interest among 11-16 year olds in high-income countries. Health-related behaviours of interest were substance use (alcohol, cigarettes and other drug use) and other behavioural risk indicators (diet, physical activity, gambling and sexual activity).

RESULTS

The review identified 41 studies, which reported 198 clusters of health-related behaviours of interest. The behaviours of interest reported within clusters were used to define eight behavioural archetypes. Some included studies only explored substance use, while others considered substance use and/or other health-related behaviours. Consequently, three archetypes were comprised by clusters reporting substance use behaviours alone. The archetypes were: (1) Poly-Substance Users, (2) Single Substance Users, (3) Substance Abstainers, (4) Substance Users with No/Low Behavioural Risk Indicators, (5) Substance Abstainers with Behavioural Risk Indicators, (6) Complex Configurations, (7) Overall Unhealthy and (8) Overall Healthy.

CONCLUSION

Studies of youth health behavioural clustering typically find both a 'healthy' cluster and an 'unhealthy' cluster. Unhealthy clusters are often characterised by poly-substance use. Our approach to synthesising cluster analyses may offer a means of navigating the heterogeneity of method, measures and behaviours of interest in this literature.

Preadult polytoxicomania-strong environmental underpinnings and first genetic hints

Considering the immense societal and personal costs and suffering associated with multiple drug use or "polytoxicomania", better understanding of environmental and genetic causes is crucial. While previous studies focused on single risk factors and selected drugs, effects of early-accumulated environmental risks on polytoxicomania were never addressed. Similarly, evidence of genetic susceptibility to particular drugs is abundant, while genetic predisposition to polytoxicomania is unexplored. We exploited the GRAS data collection, comprising information on N~2000 deep-phenotyped schizophrenia patients, to investigate effects of early-life environmental risk accumulation on polytoxicomania and additionally provide first genetic insight. Preadult accumulation of environmental risks (physical or sexual abuse, urbanicity, migration, cannabis, alcohol) was strongly associated with lifetime polytoxicomania (p  = 1.5 × 10^-45; OR = 31.4), preadult polytoxicomania with OR = 226.6 (p = 1.0 × 10^-33) and adult polytoxicomania with OR = 17.5 (p = 3.4 × 10^-24). Parallel accessibility of genetic data from GRAS patients and N~2100 controls for genome-wide association (GWAS) and phenotype-based genetic association studies (PGAS) permitted the creation of a novel multiple GWAS-PGAS approach. This approach yielded 41 intuitively interesting SNPs, potentially conferring liability to preadult polytoxicomania, which await replication upon availability of suitable deep-phenotyped cohorts anywhere world-wide. Concisely, juvenile environmental risk accumulation, including cannabis and alcohol as starter/gateway drugs, strongly predicts polytoxicomania during adolescence and adulthood. This pivotal message should launch more effective sociopolitical measures to prevent this deleterious psychiatric condition.

Prevalence and Characteristics of Borderline Intellectual Functioning in a Cohort of Patients With Polysubstance Use Disorder

Objective: To determine the prevalence and associated demographic and clinical features of borderline intellectual functioning (BIF) among individuals with polysubstance use disorder (pSUD). Methods: We applied a cross-sectional analytical design to data from the Norwegian STAYER study (n = 162), a cohort study of patients with a pSUD from the Stavanger University hospital catchment area. We used Wechsler Abbreviated Scale of Intelligence Full Scale IQ (FSIQ) to define BIF (FSIQ = 70-85) and non-BIF (FSIQ = >85) and collected demographic and clinical data using semi-structured interviews and self-reports on the Symptom Checklist 90-Revised (SCL-90-R) and the Satisfaction With Life Scale (SWLS). Results: The prevalence of BIF was 18% in the present study. The presence of BIF was associated with higher SCL-90-R GSI scores than in the non-BIF group. There were no significant differences between the BIF and non-BIF groups regarding age, gender, participation in meaningful daily activity, years of work experience, years of education, satisfaction with life, level of care, treatment attempts, age at substance-use onset, years of substance use, history of injecting drugs, or age of onset of injecting drugs. Conclusion: The present study confirmed a higher prevalence of BIF among patients with pSUD than expected from the distribution of IQ scores in a general population. Elevated SCL-90-R GSI scores suggested that BIF is associated with increased psychological distress in patients receiving treatment for pSUD. Further studies on this association, and its effect on treatment procedure and outcomes are strongly warranted.

Patterns of substance use among adolescents: A systematic review

PURPOSE

This review characterizes empirically derived patterns of multiple (multi-) substance use among adolescents. A secondary objective was to examine the extent to which mental health symptomatology was included in the empirical analyses examining substance use patterns.

METHODS

Eligible studies included those that used cluster-based approaches, included the assessment of at least two different substances, and were based on study samples with mean ages between 11 and 18 years. 4665 records were screened including 461 studies for full-text screening.

RESULTS

70 studies were included with common clusters being: low use, single or dual substance use, moderate general multi-use, and high multi-use. The most common patterns of single or multi-substance use were: alcohol only, alcohol with cannabis and/or tobacco, and use of alcohol, tobacco, and cannabis with and without other drugs. Lower socioeconomic status, older age, and male gender were consistent predictors of multi-use clusters. Only 37 % of studies compared differences in levels of mental health across clusters with symptoms consistently associated with a greater likelihood of multi-use. Only 29 % of studies included mental health indicators in cluster-based analyses, with over half identifying distinct mental health and substance use clusters. Fit indices in cluster analyses and measurement properties of substance use were heterogeneous and inconsistently reported across studies.

CONCLUSIONS

Distinct patterns of substance use were derived but methodological differences prevented direct comparison and reduced capacity to generalize across studies. There is a need to establish standardized methodological approaches to identify robust patterns of substance use to enhance etiological, prognostic, and intervention research.

Drug Use Among Adolescents and Young Adults with Unsuppressed HIV Who Use Alcohol: Identifying Patterns of Comorbid Drug Use and Associations with Mental Health

Youth living with HIV (YLWH; aged 16-24) are at elevated risk of alcohol and drug use. Studies in older populations have identified patterns or profiles of multiple substance use differentially associated with mental health and anti-retroviral therapy (ART) adherence. No studies of YLWH have yet examined such patterns. A sample of 179 YLWH, reporting ART non-adherence and alcohol use, were recruited at five Adolescent Trials Network clinics in urban areas of the US between November 2014 and August 2017. Participants completed the Alcohol Smoking and Substance Involvement Screening Test (ASSIST) to assess substance use involvement scores, and the Brief Symptom Inventory. Latent Profile Analysis identified three substance use patterns: minimal illicit drug use (15.1%), cannabis only (56.4%), and global polysubstance use (28.5%). Global polysubstance users experienced more mental health problems compared to the minimal illicit drug use group. The co-occurrence of drug use with alcohol was common among these YLWH-all of whom reported ART adherence problems-indicating the importance of interventions capable of addressing multiple substance use rather than alcohol alone.

Prevalence and correlates of youth poly-substance use in the COMPASS study

BACKGROUND AND AIMS

Youth poly-substance use, associated with long-term negative health and social outcomes, is of increasing concern following the rise of e-cigarette vaping and cannabis legalization in Canada. This work aimed to investigate current evidence on correlates of this behaviour to inform effective prevention and harm reduction programming.

DESIGN

Cross-sectional sample taking part in a cohort study.

SETTING

Canadian high schools (AB, BC, ON, QC) PARTICIPANTS: 74,501 Canadian high school students who completed the COMPASS student questionnaire in 2018/2019.

MEASUREMENTS

Self-report data on use of five substances (alcohol, cigarettes, e-cigarettes, cannabis, and opioids) alongside demographic factors, social and school support, and mental health-related measures.

RESULTS

Of the 39% of youth who reported current substance use, 53% reported using two or more. E-cigarette vaping was most prevalent (28%) and most often combined with other substances. Feeling supported by friends and having no problem with seeking help at school were associated with higher levels of poly-substance use. Family support, school connectedness, and school support to resist drugs decreased the risk of substance co-use.

CONCLUSIONS

The evidence presented here suggests that interventions for youth poly-substance use should rely on joint efforts between parents, schools, and communities to focus on structural factors rather than problematizing the individual.

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.

The changing patterns and correlates of population-level polysubstance use in Australian youth: a multi-group latent class analysis of nationally representative samples spanning 12 years

AIMS

To (1) identify population-level classes of polysubstance use among young Australians between 2004 and 2016, (2) test if these classes changed over the same period, in terms of class prevalence and probabilities of substance use within each class, and (3) identify demographic and health-related correlates of polysubstance use.

DESIGN

Repeated cross-sectional nationally representative household surveys.

SETTING

All Australian states/territories.

PARTICIPANTS

Young adult samples (aged 18-30 years; 58% females) from the National Drug Strategy Household Surveys (n = 20 350) MEASUREMENTS: Outcomes were the extent of past-year use of 10 licit (e.g. alcohol), and illicit substances (e.g. cannabis) were used to derive polysubstance use classes. The correlates were gender, age, psychological distress, general health, language background, personal income, education level, remoteness of residence and socio-economic index for area of residence.

FINDINGS

Three polysubstance use classes were consistently identified between 2004 and 2016 (SSABIC: 188349): minimal users (MU, ~60%), mainly tobacco, alcohol and cannabis users (TAC, ~30%) and extended range polysubstance users (POLY, ~10%). There were substantial changes in use of different substances within each class over the study period. For example, smoking decreased in all classes (P < 0.05), while harmful alcohol use only decreased in the first two classes (P < 0.05). Factors associated with TAC and POLY were similar over the study period. These included: being male and having an English-speaking background, a high level of psychological distress, suboptimal health and high personal income. Living in an affluent area was associated with reduced likelihood of being TAC, but an increased likelihood of being POLY.

CONCLUSION

At the population-level among young Australians between 2004 and 2016, six in 10 did not engage in polysubstance use; four in 10 used a limited range of substances (mainly alcohol, tobacco and cannabis) and one in 10 used an extended range of substances. Over time, the types of substance within the extended polysubstance use class changed substantially.

Unique versus shared associations between self-reported behavioral addictions and substance use disorders and mental health problems: A commonality analysis in a large sample of young Swiss men

BACKGROUND AND AIMS

Behavioral addictions (BAs) and substance use disorders (SUDs) tend to co-occur; both are associated with mental health problems (MHPs). This study aimed to estimate the proportion of variance in the severity of MHPs explained by BAs and SUDs, individually and shared between addictions.

METHODS

A sample of 5,516 young Swiss men (mean = 25.47 years old; SD = 1.26) completed a self-reporting questionnaire assessing alcohol, cannabis, and tobacco use disorders, illicit drug use other than cannabis, six BAs (Internet, gaming, smartphone, Internet sex, gambling, and work) and four MHPs (major depression, attention-deficit hyperactivity disorder, social anxiety disorder, and borderline personality disorder). Commonality analysis was used to decompose the variance in the severity of MHPs explained (R²) by BAs and SUDs into independent commonality coefficients. These were calculated for unique BA and SUD contributions and for all types of shared contributions.

RESULTS

BAs and SUDs explained between a fifth and a quarter of the variance in severity of MHPs, but individual addictions explained only about half of this explained variance uniquely; the other half was shared between addictions. A greater proportion of variance was explained uniquely or shared within BAs compared to SUDs, especially for social anxiety disorder.

CONCLUSIONS

The interactions of a broad range of addictions should be considered when investigating their associations with MHPs. BAs explain a larger part of the variance in MHPs than do SUDs and therefore play an important role in their interaction with MHPs.

Trends of poly-substance use among Canadian youth

INTRODUCTION

Poly-substance use, increasingly understood as a behaviour with uniquely adverse consequences, is on the rise among Canadian youth. High levels of e-cigarette vaping and the recent legalization of recreational cannabis use may result in an acceleration of this trend. The aim of this work was to characterise changes in youth poly-substance use over time, generate baseline data for future investigations, and highlight areas of interest for policy action.

METHODS

Descriptive statistics and regression models explored patterns and trends in concurrent use of multiple substances (alcohol, cigarettes, cannabis, and e-cigarettes) among Canadian high school students taking part in the COMPASS prospective cohort study during Y2 (2013/2014; n = 45,298), Y3 (2014/2015, n = 42,355), Y4 (2015/2016; n = 40,436), Y5 (2016/2017; n = 37,060), and Y6 (2017/2018; n = 34,879).

RESULTS

Poly-substance use increased significantly over time, with over 50% of students who used substance reporting past-year use of multiple substances by 2017/2018. Male and Indigenous students were significantly more likely to report poly-substance use than female and white students respectively. E-cigarette vaping doubled from Y5 to Y6 and was included in all increasingly prevalent substance use combinations.

CONCLUSIONS

Youth poly-substance use, rising since 2012/2013, saw a particularly steep increase after 2016/2017. Differential effects were observed for distinct demographic subpopulations, indicating tailored interventions may be required. E-cigarette vaping surged in parallel with the observed increase, suggesting a key role for this behaviour in shaping youth poly-substance use.

Patterns of polysubstance use and simultaneous co-use in high risk young adults

BACKGROUND

Polysubstance use (PSU) is associated with worse prognosis and poorer physical and mental health compared to single substance use. The current study provides information about PSU patterns by examining a diverse range of alcohol/substance use behaviors ranging from low-level experimentation to indicators of severe abuse. In addition, the current study, for the first time, examines how simultaneous co-use of multiple substances cluster with other more commonly studied PSU behaviors.

METHODS

Latent Class Analysis was used to identify patterns of substance use, in a sample of young-adults (n = 2098), using 25 items from the Semi-Structured Assessment for the Genetics of Alcoholism (SSAGA-II) including: items assessing severity of problems with alcohol, cannabis, stimulants, opiates, and sedatives; items assessing # of lifetime uses; items assessing simultaneous co-use of all combinations of substances. Then the association of class membership and age, antisocial and impulsive personality, experience seeking, anxiety, and neuroticism was examined using Multinomial Regression.

RESULTS

Fit indices (i.e. AIC, SSABIC, and entropy) and interpretability of classes supported a five-class solution: "Low Problems" (32% of sample), "Alcohol Primary" (11%), "Alcohol and Cannabis" (25%), "Moderate PSU" (23%), and "Severe PSU" (9%). Simultaneous co-use behaviors discriminated between lower and higher severity groups. Externalizing personality constructs robustly predicted membership in the "Moderate" and "Severe" PSU classes compared to the "Alcohol Primary" class.

CONCLUSIONS

PSU patterns followed an additive pattern of use with lower severity classes using alcohol/cannabis and more severe classes using other illicit substances in addition. Co-use items provided valuable information about PSU severity.

Reconsidering the associations between self-reported alcohol use disorder and mental health problems in the light of co-occurring addictions in young Swiss men

BACKGROUND

Alcohol use disorder (AUD) is known to co-occur with other addictions, as well as with mental health problems. However, the effects of other addictions co-occurring with AUD on mental health problems were rarely studied and not considering them may bias estimates of the association between AUD and mental health problems. This study investigated which role co-occurring addictions play for the cross-sectional associations between self-reported AUD and mental health problems.

METHOD

Participants were 5516 young Swiss men (73.0% of those that gave written informed consent) who completed a self-report questionnaire. Using short screening questionnaires, we assessed three substance use disorders (alcohol, cannabis and tobacco), seven behavioural addictions (internet, gaming, smartphone, internet sex, gambling, work, exercise) and four mental health problems (major depression, bipolar disorder, attention deficit hyperactivity disorder (ADHD) and social anxiety disorder). Differences in the proportions of mental health problems were tested using logistic regressions between (1) participants with no AUD and AUD, (2) participants with no AUD and AUD alone and (3) participants with no AUD and AUD plus at least one co-occurring addiction.

RESULTS

Overall, (1) participants with AUD had higher proportions of major depression (Odds ratio (OR [95% confidence interval]) = 3.51 [2.73, 4.52]; ADHD (OR = 3.12 [2.41, 4.03]); bipolar disorder (OR = 4.94 [3.38, 7.21]) and social anxiety (OR = 2.21 [1.79, 2.73])) compared to participants with no AUD. Considering only participants with AUD alone compared to participants with no AUD (2), differences in proportions were no longer significant for major depression (OR = 0.83 [0.42, 1.64]), bipolar disorder (OR = 1.69 [0.67, 4.22]), social anxiety (OR = 1.15 [0.77, 1.73]) and ADHD (OR = 1.65 [1.00, 2.72]) compared to participants with no AUD. In contrast, (3) proportions of mental health problems were considerably higher for participants with AUD plus at least one other addiction when compared to participants with no AUD, with OR's ranging from 2.90 [2.27, 3.70] for social anxiety, 4.03 [3.02, 5.38] for ADHD, 5.29 [4.02, 6.97] for major depression to 6.64 [4.44, 9.94] for bipolar disorder.

CONCLUSIONS

AUD was associated with all four measured mental health problems. However, these associations were mainly due to the high proportions of these mental health problems in participants with AUD plus at least one co-occurring addiction and only to a lesser degree due to participants with AUD alone (i.e. without any other co-occurring addictions). Hence, estimates of the association between AUD and mental health problems that do not consider other addictions may be biased (i.e. overestimated). These findings imply that considering addictions co-occurring with AUD, including behavioural addictions, is important when investigating associations between AUD and mental health problems, and for the treatment of AUD and co-morbid disorders.

A retrospective examination of antisocial and risk-taking behaviours

Engagement in antisocial and risk-taking behaviours is a recurring issue that has been associated with a range of negative outcomes for the individual, community, and society. This research explored factors that influenced engagement and co-occurring behaviours. Responses (n = 393) from an Australian sample who completed the Antisocial Engagement Questionnaire showed that the majority of the behaviours of interest were associated, indicating that engagement in one behaviour was associated with engagement in additional antisocial and risk-taking behaviours. Engagement in antisocial behaviours was also associated with increased substance consumption. An investigation into the associations between 15 substance-related behaviours found that use of one substance was associated with the use of additional substances. The findings have implications for understanding the development of an antisocial lifestyle, the associations between behaviours, the findings build on research relating to behaviour prediction and will assist clinicians working with at-risk individuals and intervention design.

Types of Polydrug Use Among Spanish Students in Health Sciences

Polydrug use among university students may be a predictor for established patterns of multiple substance use and potentially entail long-term health problems. This study examined the types of polydrug use among Spanish students in health sciences. Undergraduate students (n = 968), aged 18-38 years (M = 21.09 years, SD = 4.10), completed the survey. A percentage of 44.3% of the participants were classified as polydrug users. Type A users (alcohol and cigarettes) made up 17.8% of the participants surveyed, whereas 20.1% were Type B (cannabis with cigarettes and/or alcohol), and a further 5.7% were Type C (cannabis with cigarettes and/or alcohol, plus at least another kind of illegal drug). Type A was the most common type among women, whereas Type C was the most common among men. Type B use was higher among women 18-19 years old than among women 25-29 years old, whereas there were no female Type C users younger than 20 years old. Weekend consumption was higher, than weekday consumption, across all polydrug user types and substances. These results suggest that the prevalence of polydrug use among Spanish students in health sciences was similar to students in other disciplines, with Type B as the most prevalent among healthcare and nonhealthcare students. Taking into account the differences based on gender, age, and time of consumption, a specific approach to the different typologies of polydrug users might be a vital step in the successful development of preventive interventions tailored to the changing reality of psychoactive substance use.

Latent Classes of Polysubstance Use Among Adolescents in the United States: Intersections of Sexual Identity with Sex, Age, and Race/Ethnicity

PURPOSE

We aimed to estimate latent classes of concurrent polysubstance use and test for sexual orientation differences in latent class memberships with representative data from adolescents living in 19 U.S. states. We also tested whether sex, race/ethnicity, and age moderated the sexual identity differences in polysubstance use class memberships.

METHODS

We analyzed data from 119,437 adolescents from 19 states who participated in the 2015 Youth Risk Behavior Survey. Latent class analysis characterized polysubstance use patterns based on self-reported frequency of lifetime and past-month use of alcohol (including heavy episodic drinking), tobacco (cigarettes, cigars, and smokeless tobacco), and marijuana. Multinomial logistic regression models tested differences in latent class memberships by sexual identity. Interaction terms tested whether sex, race/ethnicity, and age moderated the sexual identity differences in polysubstance use class memberships.

RESULTS

A six-class model of polysubstance use fit the data best and included nonusers (61.5%), experimental users (12.2%), marijuana-alcohol users (14.8%), tobacco-alcohol users (3.8%), medium-frequency three-substance users (3.6%), and high-frequency three-substance users (4.1%). Gay/lesbian- and bisexual-identified adolescents had significantly higher odds than heterosexual-identified adolescents of being in all of the user classes compared with the nonuser class. These sexual identity differences in latent polysubstance use class memberships were generally larger for females than for males, varied occasionally by race/ethnicity, and were sometimes larger for younger ages.

CONCLUSION

Compared with their heterosexual peers, gay/lesbian and bisexual adolescents-especially females-are at heightened risk of engaging in multiple types of polysubstance use. Designing, implementing, and evaluating interventions will likely reduce these sexual orientation disparities.

A latent class analysis of the past-30-day substance use patterns among lifetime cocaine users: Findings from a community sample in North Central Florida

Objectives

Cocaine use is increasing and many cocaine users engage in polysubstance use. Within polysubstance use, relationships among use of individual substances are necessarily complex. To address this complexity, we used latent class analysis (LCA) to identify patterns of polysubstance use among lifetime cocaine users and examine associations among these patterns, demographics, and risk profiles.

Methods

Members of HealthStreet, an ongoing community engagement program, were asked about lifetime and past 30-day use of cocaine, alcohol, tobacco, marijuana, and prescription medications, mental health conditions, recent Emergency Department (ED) visits and demographics. LCA was used to identify classes of past 30-day polysubstance use among individuals who endorsed lifetime cocaine use. Multinomial logistic regression identified factors associated with these classes.

Results

Among 1797 lifetime cocaine users, a five-class LCA model was identified: 1) past 30-day tobacco use only (45%), 2) past 30-day alcohol, marijuana and tobacco use (31%), 3) past 30-day tobacco, prescription opioid and sedative use (13%), 4) past 30-day cocaine, alcohol, marijuana and tobacco use (9%), 5) past 30-day cocaine and multiple polysubstance use (2%). Demographics, ED visits and mental health conditions were associated with class membership.

Conclusions

Approximately 11% of lifetime cocaine users used cocaine in the past 30 days with two different concurrent substance use patterns. Prescription medication (opioids and sedatives) and complex polysubstance use patterns were stronger indicators of negative outcomes than current cocaine use. Cocaine was not used frequently with other stimulants. In addition to polysubstance use, prescription medication use should be targeted for intervention among lifetime cocaine users.

Non-medical use of pharmaceutical opioids with and without other illicit substances in Australia: Prevalence and correlates

INTRODUCTION AND AIMS

To estimate the prevalence of non-medical use of pharmaceutical opioids and examine the socio-demographic, psychological, health and behavioural correlates and type of opioids used.

DESIGN AND METHODS

Data from the Australian National Drug Strategy Household Survey 2016 was used. The sample consisted of. 23 448 participants aged over 14 years (54% female). The key measure was opioid use status in the past year. Based on participants' responses to questions about their substance use in the past 12 months, they were grouped into four opioid use status: (i) No illicit substance use (ISU) and no non-medical use of pharmaceutical opioids (NMUPO); (ii) ISU but no NMUPO; (iii) NMUPO but no ISU; and (iv) NMUPO and ISU.

RESULTS

The prevalence non-medical pharmaceutical opioid use was 3.56%. Two-thirds of them engaged in NMUPO but no ISU; one-third engaged in NMUPO and ISU. Younger people were more likely to use pharmaceutical opioids in addition to other illicit drugs, while older people were more likely to only use pharmaceutical opioids. Alcohol risk and daily smoking were associated with using pharmaceutical opioids and other illicit drugs, but not with pharmaceutical opioids only. Those who reported only using pharmaceutical opioids were more likely to use over-the-counter codeine products.

DISCUSSION AND CONCLUSIONS

Over 700 000 Australian used pharmaceutical opioids for non-medical purpose. Among users, two-thirds used only opioids and one-third used opioids in addition to other illicit drugs. Profile of these two types of users were substantially different. Future prevention efforts targeting different type of opioids users may need to be optimised based on their profiles.

Poly-use of cannabis and other substances among juvenile-justice involved youth: variations in psychological and substance-related problems by typology

BACKGROUND

Adolescent cannabis use is associated with increased risk for psychological problems, with evidence for more severe problems among youth who use cannabis in combination with other substances (i.e., polysubstance use). Juvenile offenders engage in both cannabis use and polysubstance use at higher rates than the general adolescent population. Yet, limited research has examined the relationship between cannabis poly-use (e.g., cannabis and alcohol use) and functional or psychological problems among juvenile offenders.

OBJECTIVES

The current study addresses this gap by examining the association of polysubstance use of cannabis compared to cannabis only use with cognitive functioning, psychological distress, and substance-related problems among juvenile detainees.

METHODS

Participants were 238 detained youth ages 12-18 (80.4 % male, 77.3% non-White) who completed assessments of substance use, intellectual functioning, psychological symptoms, and substance-related problems. Youth were also assessed by a clinical psychologist for substance use disorder.

RESULTS

Four cannabis-use typologies were identified; cannabis and alcohol use was the largest class, followed by cannabis only use, cannabis, alcohol and other drug use, then cannabis and other drug use. Polysubstance use was associated with lower scores on measures of intellectual functioning, more externalizing and internalizing symptomology, and more substance-related problems relative to cannabis only use. However, the relationship between polysubstance use and problems varied by typology.

CONCLUSIONS

Findings suggest that justice-involved youth engaged in polysubstance use may be at greater need for concurrent academic, affective, and behavioral support in their rehabilitation and transition back to the community.

Universal cannabis outcomes from the Climate and Preventure (CAP) study: a cluster randomised controlled trial

Background

The Climate and Preventure (CAP) study was the first trial to assess and demonstrate the effectiveness of a combined universal and selective approach for preventing alcohol use and related harms among adolescents. The current paper reports universal effects from the CAP study on cannabis-related outcomes over three years.

Methods

A cluster randomized controlled trial was conducted with 2190 students from twenty-six Australian high schools (mean age: 13.3 yrs., SD 0.48). Participants were randomised to one of four conditions; universal prevention for all students (Climate); selective prevention for high-risk students (Preventure); combined universal and selective prevention (Climate and Preventure; CAP); or health education as usual (Control). Participants were assessed at baseline, post intervention (6–9 months post baseline), and at 12-, 24- and 36-months, on measures of cannabis use, knowledge and related harms. This paper compares cannabis-related knowledge, harms and cannabis use in the Control, Climate and CAP groups as specified in the protocol, using multilevel mixed linear models to assess outcomes.

Results

Compared to Control, the Climate and CAP groups showed significantly greater increases in cannabis-related knowledge initially (p <  0.001), and had higher knowledge at the 6, 12 and 24-month follow-ups. There was no significant difference between the Climate and CAP groups. While no differences were detected between Control and the CAP and Climate groups on cannabis use or cannabis-related harms, the prevalence of these outcomes was lower than anticipated, possibly limiting power to detect intervention effects. Additional Bayesian analyses exploring confidence in accepting the null hypothesis showed there was insufficient evidence to conclude that the interventions had no effect, or to conclude that they had a meaningfully large effect.

Conclusions

Both the universal Climate and the combined CAP programs were effective in increasing cannabis-related knowledge for up to 2 years. The evidence was inconclusive regarding whether the interventions reduced cannabis use and cannabis-related harms. A longer-term follow-up will ascertain whether the interventions become effective in reducing these outcomes as adolescents transition into early adulthood.

Trial registration

This trial was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12612000026820) on the 6th of January 2012, https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=347906&isReview=true

Electronic supplementary material

The online version of this article (10.1186/s13011-018-0171-4) contains supplementary material, which is available to authorized users.

Predictors of initiation of nicotine, alcohol, cannabis, and cocaine use: Results of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

BACKGROUND AND OBJECTIVES

There may be substantial overlap in the risk factors for substance use and substance use disorders (SUD). Identifying risk factors for substance use initiation is essential for understanding the etiology and natural history of SUD and to develop empirically-based preventive interventions to reduce initiation.

METHODS

Analyses were done on Wave 1 participants of the National Epidemiological Survey of Alcohol and Related Conditions (NESARC) (n = 43,093). Estimates of the cumulative probability of substance use initiation were obtained separately for nicotine, alcohol, cannabis, and cocaine. Survival analyses with time-varying covariates were implemented to identify risk factors for substance initiation.

RESULTS

The lifetime cumulative probabilities of substance initiation were 45.5% for nicotine, 82% for alcohol, 19.6% for cannabis, and 6.4% for cocaine. Among respondents with lifetime nicotine use, 50% had used it by age 15.3, whereas for alcohol, cannabis, and cocaine the respective ages were 17.8, 16.6, and 19.8. Previous use of another substance, being male, having a cluster B personality disorder, family history of SUD, and being separated, divorced, or widowed increased the risk of use of all the substances assessed, whereas social anxiety disorder and some personality disorders were associated with specific substances.

DISCUSSION AND CONCLUSIONS

Although the age of substance use initiation varies by substance, in more than 50% of cases initiation of use occurs in the first two decades of life. Although most risk factors for substance use initiation are common across substances, some are substance-specific.

SCIENTIFIC SIGNIFICANCE

This information may help in the development of empirically-based preventive interventions. (Am J Addict 2018;27:477-484).

Age of Onset, Current Use of Alcohol, Tobacco or Marijuana and Current Polysubstance Use Among Male and Female Mexican Students

Aims

This study aimed to examine alcohol, tobacco or marijuana use onset and associations between age of onset and current use, and between age of onset and current polysubstance use among a sample of Mexican young people aged 17-20 years.

Methods

Alcohol, tobacco, marijuana and other substance use were identified in a 2012 cross-sectional survey of male and female students entering first year university in Mexico City. Chi-square tests and logistic regression models examined associations between gender, age of onset, order of onset, family substance use and current polysubstance use among 22,224 students.

Results

The largest proportions of males and females initiated alcohol at age 15, tobacco at ages 15-16 and marijuana at ages 16-17. Earlier alcohol and tobacco initiation was associated with past 30-day use of the same substance. Gender differences in alcohol and tobacco use were small but males were significantly more likely than females to use marijuana and be polysubstance users. Family substance use was associated with earlier onset. There was a significant association between the earliest age of any of the three substances and current polysubstance use.

Conclusions

A number of contextual and cultural factors in Mexico may be contributing to early onset, continued use and polysubstance use and deserve attention in research and by prevention programs.

Gradient of association between parenting styles and patterns of drug use in adolescence: A latent class analysis

BACKGROUND

To identify different patterns of drug use in adolescence and determine if these are associated with parenting styles and other sociodemographic factors.

METHODS

A latent class analysis was conducted using baseline data collected in a sample (n=6381) from a randomized controlled trial conducted to evaluate the effectiveness of the #Tamojunto drug-use prevention program, carried out with 7th- and 8th-grade public school students in six Brazilian cities.

RESULTS

Three latent classes were identified among the students: 1) abstainers/low users (81.54%), 2) alcohol users/binge drinkers (16.65%), and 3) polydrug users (1.80%). A gradient of inverse association was found between parenting styles (authoritative, authoritarian, and indulgent, with the neglectful style as a reference point) and the classes "alcohol users/binge drinkers" (aOR=0.36, 95%CI=0.27-0.47; aOR=0.56, 95%CI=0.43-0.72; and aOR=0.64, 95%CI=0.51-0.80, respectively) and "polydrug users" (aOR=0.09, 95%CI=0.03-0.24; aOR=0.23, 95%CI=0.11-0.52; and aOR=0.24, 95%CI=0.08-0.74, respectively). Associations were also revealed between the latent classes and the adolescent's age and socioeconomic status.

CONCLUSION

The results suggest that activities to develop parenting skills should be included in school programs aimed at the prevention of drug use among adolescents in order to reduce neglectful practices and thereby possibly reduce drug use among the children.

Polysubstance Use Among Adolescents in a Low Income, Rural Community: Latent Classes for Middle- and High-School Students

PURPOSE

Rural communities are currently being impacted by a nationwide epidemic of prescription opioid misuse. Rural adolescent substance users may be at substantial risk for later addiction to these and other drugs.

METHODS

This study uses Latent Class Analysis to identify subtypes of polysubstance users among a sample of 7,074 rural adolescents. Separate models were estimated for middle- and high-school youth. Predictive validity was estimated using cumulative ordinal logistic regression of the classes on a set of youth and family characteristics.

FINDINGS

We identified a 4-class solution for both middle- and high-school students marked by initiation of an increasing number of substances used at greater frequency. These classes included Substance Nonusers, Primarily Alcohol Users, Initiators-Low Frequency Users, and Initiators-Moderate-to-High Lifetime Frequency Users. About 6%-10% of youth reported using prescription drugs at least once, and in the moderate-to-high frequency class, middle-school youth were more likely to use prescription drugs and inhalants compared to high-school youth in the same class. The 4 classes were associated with race/ethnicity, and in high school with receiving free/reduced price lunch.

CONCLUSION

In general, younger adolescents have lower overall use rates, but within certain classes identified by this analysis, the observed pattern suggests that younger cohorts are turning to prescription drugs and inhalants. These findings support the implementation of universal substance use prevention programs, targeted programs for youth experiencing risk factors associated with substance use, and improved rural substance abuse treatment options.

Identifying "social smoking" U.S. young adults using an empirically-driven approach

The phenomenon of "social smoking" emerged in the past decade as an important area of research, largely due to its high prevalence in young adults. The purpose of this study was to identify classes of young adult ever smokers based on measures of social and contextual influences on tobacco use. Latent class models were developed using social smoking measures, and not the frequency or quantity of tobacco use. Data come from a national sample of young adult ever smokers aged 18-24 (Truth Initiative Young Adult Cohort Study, N=1564). The optimal models identified three latent classes: Class 1 - nonsmokers (52%); Class 2 - social smokers (18%); and Class 3 - smokers (30%). Nearly 60% of the "social smoker" class self-identified as a social smoker, 30% as an ex-smoker/tried smoking, and 12% as a non-smoker. The "social smoker" class was most likely to report using tobacco mainly or only with others. Past 30-day cigarette use was highest in the "smoker" class. Hookah use was highest in the "social smoker" class. Other tobacco and e-cigarette use was similar in the "social smoker" and "smoker" classes. Past 30-day tobacco and e-cigarette use was present for all products in the "non-smoker" class. Young adult social smokers emerge empirically as a sizable, distinct class from other smokers, even without accounting for tobacco use frequency or intensity. The prevalence of hookah use in "social smokers" indicates a group for which the social aspect of tobacco use could drive experimentation and progression to regular use.

Polydrug use by European adolescents in the context of other problem behaviours

Aim

Previous studies of the association between polydrug use and other risk behaviours have generally been limited to specific substances and a small number of behaviours. The aim of this study is to obtain better insight into polydrug use (comprising legal and illegal substances: tobacco, alcohol, tranquillisers/sedatives, cannabis, and other illegal drugs) and its association with co-occurring problem behaviours drawn from various broad domains (sexual, aggressive, delinquent, school achievement, relationships) among European adolescents.

Methods

Data were obtained from 101,401 16-year-old students from 35 European countries participating in the 2011 ESPAD survey. Associations between polydrug use and other problem behaviours were examined by multinomial and binary logistic regression analyses.

Results

Tranquillisers/sedatives appeared among the commonest combinations in the polydrug use pattern, especially for females. A strong trend was found between levels of involvement with polydrug use and other problem behaviours for both genders. The highest associations with polydrug use were for problems with the police, risky sexual behaviour and skipping school. Gender differences showed higher prevalences among boys than girls of problem behaviours of aggressive, antisocial type, while girls prevailed over boys in relationship problems.

Conclusion

An incremental relationship exists between the level of involvement with polydrug use and the co-occurrence of problem behaviours. Preventative interventions should consider the misuse of tranquillisers/sedatives within the context of polydrug use by adolescents and expand their target groups towards multiple problem behaviours.

Concurrent polysubstance use in a longitudinal study of US youth: associations with sexual orientation

AIMS

To estimate longitudinal associations between self-reported sexual orientation and past-year polysubstance use among youth, and test how gender, age and early onset of tobacco and alcohol use contributed to variation in polysubstance use.

DESIGN

Longitudinal community-based cohort of US adolescents from the Growing Up Today Study (GUTS 1) (n = 16 873) followed from ages 12-29 years.

SETTING

United States of America.

PARTICIPANTS

A total of 13 519 individuals (7839 females; 5680 males) who responded to at least one of five self-administered questionnaires from 1999 to 2010. Ninety-three per cent reported their race/ethnicity as non-Hispanic white.

MEASUREMENTS

Multivariable repeated measures generalized estimating equations estimated relative risks (RRs) of concurrent polysubstance use (i.e. past 12-month use of three or more substances) comparing sexual orientation minority youth [i.e. mostly heterosexual (MH), bisexual (BI), gay/lesbian (GL)] to their same-gender, completely heterosexual (CH) counterparts. Mediation analyses tested whether early onset of tobacco and/or alcohol use explained relationships between sexual orientation and concurrent polysubstance use.

FINDINGS

Compared with their same-gender CH peers, sexual minorities evidenced higher risk for concurrent polysubstance use over all repeated measures [risk ratios (RRs) for sexual minority subgroups: from 1.63-2.91, P-values: <0.001] and for all age groups (RRs: from 1.50-4.04, P-values: < 0.05-< 0.001), except GL males aged 18-20 years. Differences between sexual minorities and CHs were larger among females than males (P-values for sexual orientation × gender interactions were < 0.05 for MHs and BIs), and among younger versus older ages (P-values for sexual orientation × age interactions were < 0.05, except for BI males). Sexual minorities' younger age of smoking and/or drinking initiation contributed to their elevated polysubstance use (% of effect explained was between 9.4-24.3, P-values: 0.04-< 0.001), except among GL males.

CONCLUSIONS

Sexual minority youth in the United States, and in particular younger females, appear to be at disproportionate risk for concurrent past-year polysubstance use. Early onset of smoking and drinking may contribute to elevated risk of polysubstance use among sexual minorities.

Substance Use Profiles Among Juvenile Offenders: A Lifestyles Theoretical Perspective

Base rates of illicit substances such as cocaine, crack cocaine, and heroin are typically low in community-based studies, which often inhibit more complex multivariate analysis. Additionally, single-item measures and aggregate scales mask within-group differences among those showing versatility in their substance use. Latent class analysis was used to model the substance use profiles of adjudicated female ( n = 98) and male ( n = 378) youth. Alcohol, marijuana, acid, mushrooms, ecstasy, cocaine, crack cocaine, heroin, crystal methamphetamine, and nonmedical use of prescription pills were used to define latent profiles of substance use. Three latent classes were identified that were qualitatively different across males and females. Multinomial logistic regression analyses indicated that time spent outside of the home of the biological parents, early substance use, and parental substance abuse were informative of the use of substances such as cocaine, crack cocaine, and heroin. Implications for more individualized treatment strategies are discussed.

Longitudinal Conjoint Patterns of Alcohol and Tobacco Use Throughout Emerging Adulthood

BACKGROUND

The concurrent use of alcohol and tobacco has a multiplicative effect on both social and physical consequences. While it is known that alcohol and tobacco use are strongly correlated in emerging adulthood, there is significant individual variability in use. However, little research has examined how patterns of concurrent use are related over time.

OBJECTIVES

The current study explores these longitudinal conjoint trajectories, as well as the associated sociodemographic factors.

METHODS

We used sequential latent class growth analysis to explore the co-occurring longitudinal patterns of recent alcohol and tobacco use across emerging adulthood (10 data collection periods, 2004-2009) with a diverse sample of 2,244 college students (60% female; 54% White).

RESULTS

Twenty distinct patterns of conjoint alcohol and tobacco use were found. There was more variation in tobacco use trajectories among alcohol users than variation in alcohol trajectories among tobacco users. Using multinomial logistic regression models we determined the impact of sociodemographic characteristics on classification into each conjoint pattern versus the normative trajectory (Abstaining tobacco/Low alcohol). Male gender, White race, fraternity/sorority affiliation, and higher family income were significantly associated with riskier conjoint trajectory patterns. Conclusions/Importance: Findings highlight the diversity of alcohol and tobacco use behaviors across emerging adulthood. The low variation in alcohol use among tobacco users indicates that tobacco use is a significant risk factor for heavier drinking. A better understanding of the covarying use of these two ubiquitous substances may provide new avenues for preventing and reducing the use of both.

Peer drug use and adolescent polysubstance use: Do parenting and school factors moderate this association?

AIMS

This study examined the association between peer drug use and adolescent polysubstance use, and investigated if this association was moderated by parenting and/or school factors.

METHODS

The sample consisted of 9966 participants (mean age=14.3; 49.34% males) randomly selected from secondary schools in Victoria, Australia. Three 30-day polysubstance use profiles were derived from latent class analysis - no drug use (47.7%), mainly alcohol use (44.1%) and polysubstance use (8.2%). These profiles were then regressed on peer's drug use, family conflict, parental monitoring, parental disapproval of drug use, school commitment, reward for prosocial involvement in school and academic failure, and the interactions between peer's drug use and each of the parenting and school variables.

RESULTS

Relative to non-users, peer's drug use was strongly associated with polysubstance use (OR=30.91, p<0.001), and this association was moderated by parental disapproval of drug use (OR=0.46, p<0.001). This indicated that high level of parental disapproval may mitigate the negative influence of drug using peers. School commitment and parental monitoring were significantly associated with reduced likelihood of polysubstance use (p<0.05), but they did not moderate the relationship between peer drug use and adolescent polysubstance use. All analyses were adjusted for key demographic factors such as age, gender, areas of residence, birth place and family affluence.

CONCLUSION

Reinforcing parent disapproval of drug use may be an important strategy in reducing adolescent substance use. Parents may need to be more integrated into mainstream prevention programs.

[Drug use and treatment misuse: Key points on polydrug use]

Problematic use of psychoactive drugs, be it legal, on prescription, or not, remains a broad phenomenon when taken as a whole, with an increasingly large spectrum of used products. The polysubstance drug use is an expanding new trend. Although its epidemiological analysis is complex, needing further research, certain patterns of drug combinations can be found, allowing to identify clusters of users associated to more specific medical and social risks. Managing polysubstance users involves assessing each drug use, but also the connections between drugs and the patient's expectations for each of them. Complications, as well as psychiatric and somatic comorbidities are to be taken into account. The therapeutic tools for polysubstance drug use, mainly pharmacological, are still often limited to the sum of specific tools for each product. Prevention is crucial but has to adapt to the identified use clusters, and the gender. Notably, a good knowledge of chronic pain management and prescribed drug dependency risks is required to prevent polysubstance drug use involving opioids.

Mostly Smokers: Identifying Subtypes of Emerging Adult Substance Users

BACKGROUND

The concurrent use of marijuana and other substances among emerging adults (ages 18-25) is a major public health problem. This study examined if there are distinct subtypes of emerging adult marijuana users and if these are associated with demographic and substance use variables.

METHODS

The design was a cross-sectional interview with a community sample of 1,503 emerging adults in the northeastern U.S. who reported last month marijuana use. We used latent class analysis (LCA) to identify distinct subtypes of emerging adults who used additional substances and examined predictors of the latent classes.

RESULTS

We identified three distinct classes of emerging adults who use substances: "mostly smokers" (those who primarily use marijuana and nicotine), "moderate users" (those who primarily use marijuana and/or heavy episodic alcohol), and "polysubstance users." Polysubstance users had higher probabilities of use of all assessed substances (e.g. cocaine, opiates, sleep medications, stimulants, synthetic marijuana, and inhalants) than the other two groups. Not being currently enrolled in school and male gender were associated with mostly smokers and polysubstance users group status.

CONCLUSIONS

We identified a distinct group of emerging adult marijuana users who primarily smoke marijuana and cigarettes, suggesting that there could be a shared vulnerability for risk of co-occurrence.

Does gender moderate the relationship between polydrug use and sexual risk-taking among Australian secondary school students under 16 years of age?

INTRODUCTION AND AIMS

This study examines the association of alcohol and polydrug use with risky sexual behaviour in adolescents under 16 years of age and if this association differs by gender.

DESIGN AND METHODS

The sample consisted of 5412 secondary school students under 16 years of age from Victoria, Australia. Participants completed an anonymous and confidential survey during class time. The key measures were having had sex before legal age of consent (16 years), unprotected sex before 16 (no condom) and latent-class derived alcohol and polydrug use variables based on alcohol, tobacco, cannabis, inhalants and other illegal drug use in the past month.

RESULTS

There were 7.52% and 2.55% of adolescents who reported having sex and having unprotected sex before 16 years of age, respectively. After adjusting for antisocial behaviours, peers' drug use and family and school risk factors, girls were less likely to have unprotected sex (odds ratio = 0.31, P = 0.003). However, the interaction of being female and polydrug use (odds ratio = 4.52, P = 0.004) was significant, indicating that girls who engaged in polydrug use were at higher risk of having unprotected sex. For boys, the effect of polydrug use was non-significant (odds ratio = 1.44, P = 0.310). Discussion and Conclusions For girls, polydrug use was significantly associated with unprotected sex after adjusting for a range of risk factors, and this relationship was non-significant for boys. Future prevention programs for adolescent risky sexual behaviour and polydrug use might benefit from a tailored approach to gender differences. [Chan GCK, Kelly AB, Hides L, Quinn C, Williams JW. Does gender moderate the relationship between polydrug use and sexual risk-taking among Australian secondary school students under 16 years of age? Drug Alcohol Rev 2016;35:750-754].

Latent classes of polysubstance use among adolescents-a systematic review

BACKGROUND

This systematic review aims to summarize latent classes of polysubstance use in adolescents (10-19 years), and to describe predictors of polysubstance use.

METHODS

A systematic literature review was conducted in three databases (PUBMED, PsycINFO, PsycARTICLES) to identify peer-reviewed articles on latent classes of adolescent polysubstance use (published through June 30, 2015), and to assess the comparability of their results.

RESULTS

23 studies (N=450-N=419,698) met the inclusion criteria. The studies showed predominantly (18 studies) average to low risk of bias. 17 studies (74%) identified between three or four latent classes, with "no use" or "low use" classes being the largest and "polysubstance use" being the smallest ones. Intermediate classes included extensive single substance use, such as "alcohol only" classes. Polysubstance use classes were unanimously predicted by higher age, higher parental and peer substance use, and poor academic performance, other predictors were highly heterogeneous.

CONCLUSIONS

Latent classes deliver solid information on polysubstance use in adolescence. Despite their sample sensitivity, the studies possess manifold similarities, hence, modeling latent classes seems to be an ecologically valid approach to further research, e.g., for subgroup analyses or on substance use trajectories. Finally, latent classes may help to illustrate differential effects and special groups in prevention and treatment that depend on the actual consumption pattern. However, there are certain methodological recommendations to be considered in order to obtain reliable results.

Predictors of comorbid polysubstance use and mental health disorders in young adults-a latent class analysis

AIM

The co-occurrence of mental health and substance use disorders adds complexity to already-significant health burdens. This study tests whether mental health disorders group differently across substance use disorder types and compares associations of early factors with the development of differing comorbidities.

DESIGN

Consecutive antenatal clinic attendees were recruited to the longitudinal Mater-University of Queensland Study of Pregnancy (MUSP). Mother/offspring dyads were followed over 21 years.

SETTING

Mater-Misericordiae Public Hospital, Brisbane, Australia.

PARTICIPANTS

MUSP offspring with maternal baseline information (n = 7223), offspring behaviour data at 14 (n = 4815) and psychiatric diagnoses at 21 (n = 2575).

MEASUREMENTS

The Composite International Diagnostic Interview yielded life-time diagnoses of mental health (MH) and substance use (SU) disorders for offspring, then latent class modelling predicted membership of polydisorder groups. We fitted the resulting estimates in multinomial logistic regression models, adjusting for maternal smoking, drinking and mental health, adolescent drinking, smoking and behaviour and mother-child closeness.

FINDINGS

Fit indices [Bayesian information criterion (BIC) = 12 415; Akaike information criterion (AIC) = 12 234] from LCA supported a four-class solution: low disorder (73.6%), MH/low SU disorder (10.6%), alcohol/cannabis/low MH disorder (12.2%) and poly SU/moderate MH disorder (3.5%). Adolescent drinking predicted poly SU/MH disorders [odds ratio (OR) = 3.34, 95% confidence interval (CI) = 1.42-7.84], while externalizing predicted membership of both SU disorder groups (ORalcohol/cannabis  = 2.04, 95% CI = 1.11-3.75; ORpolysubstance  = 2.65, 95% CI = 1.1-6.08). Maternal smoking during pregnancy predicted MH (OR = 1.53, 95% CI = 1.06-2.23) and alcohol/cannabis-use disorders (OR = 1.73; 95% CI = 1.22-2.45). Low maternal warmth predicted mental health disorders only (OR = 2.21, 95% CI = 1.32-3.71).

CONCLUSIONS

Mental health disorders are more likely in young adults with polysubstance use disorders than those with alcohol/cannabis use disorders. Predictors of comorbid mental health/polysubstance use disorders differ from those for alcohol/cannabis use disorders, and are detectable during adolescence.

Teen Dating Violence Victimization and Patterns of Substance Use Among High School Students

PURPOSE

Substance use in adolescence is a significant concern, particularly the use of multiple drugs. Yet, most studies examine a single substance in isolation, with limited consideration of the use of multiple substances. Furthermore, few studies have examined how teen dating violence (TDV) victimization is associated with patterns of substance use.

METHODS

Using latent class analysis and latent class regression, the present study aimed to (1) identify subtypes of substance use among high school students and (2) examine the association between past-year physical and psychological TDV victimization and pattern of substance use. We focused on 30-day use of alcohol, binge drinking, marijuana, cigarette, cigarillo, and prescription drug use. Analyses were conducted on data from 18,680 adolescents in Grades 9-12, across 58 high schools.

RESULTS

The latent class analysis indicated a five-class model best fit the data; the largest class was composed of nonusers, whereas the other classes were high polysubstance use, alcohol use, alcohol and marijuana use, and moderate polysubstance use. The multinomial regression analyses indicated that adolescents who had experienced physical and psychological TDV were more likely to be in the two polysubstance use classes and the alcohol and marijuana use class, as compared with nonvictimized adolescents.

CONCLUSION

There is heterogeneity in adolescents' self-reported recent substance use, although a large proportion of substance-using youth reported recent alcohol and marijuana use. Preventive interventions should focus their efforts on preventing substance use among victims of TDV, in part because substance use is a risk factor for TDV victimization.

Co-occurrence between mental distress and poly-drug use: a ten year prospective study of patients from substance abuse treatment

INTRODUCTION

Longitudinal research investigating psychiatric trajectories among patients with poly-drug use patterns remains relatively scant, even though this specific population is at elevated risk for multiple negative outcomes. The present study examined temporal associations between poly-drug use (i.e. heroin, cannabis, tranquilizers, and amphetamines) and mental distress over a 10-year period.

METHODS

A clinical cohort of 481 patients was recruited from substance use treatment facilities in Norway, and prospectively interviewed 1, 2, 7 and 10years after the initial data collection at treatment admission. At each assessment participants completed a questionnaire addressing their substance use and mental distress. Longitudinal growth models were used to examine whether, and if so, how, levels of drug use were associated with the level and rate of change in mental distress over time.

RESULTS

Results from the longitudinal growth models showed a co-occurrence between active poly-drug use and mental distress, such that there was a dose-response effect where mental distress increased both in magnitude and over time with the number of drugs used. Reduction in mental distress during the 10-year study period was evident only in the no-drug use condition. Use of multiple drugs and mental distress appear strongly co-related over time.

CONCLUSIONS

Pre-treatment assessment should carefully identify individuals manifesting poly-drug use and mental disorders. Treatment and follow-up services should be tailored to their specific needs.