Substance use initiation: the role of simultaneous polysubstance use

Stressful Life Events and Patterns of Polysubstance Use Among U.S. Late Middle-Aged and Older Adults: A Latent Class Analysis

The goals of this study were to identify patterns of polysubstance use and their associations with stressful life events among U.S. late middle-aged and older adults and examine whether gender moderates these associations. Adults aged 50 and older (N = 14,738) from the National Epidemiological Survey on Alcohol and Related Conditions-III were included. Latent class analysis was conducted to identify patterns of polysubstance use. Weighted multinomial logistic regression was estimated with a generalized structural equation model. Three different polysubstance use patterns (non-users/low substance users; cannabis and excessive alcohol users; painkiller and sedative/tranquilizer misusers) were identified. Higher levels of stressful life events were associated with patterns of polysubstance use. Gender moderated the association between stressful life events and co-misusing painkillers and sedatives/tranquilizers (p < 0.05). Substance use prevention efforts should consider aging adults' patterns of polysubstance use and associated stressful life events when designing and implementing gender-specific polysubstance use prevention interventions.

Altered functional connectivity and oscillatory dynamics in polysubstance and cannabis only users during visuospatial processing

RATIONALE AND OBJECTIVES

Cannabis use is often associated with the use of other psychoactive substances, which is subsequently linked to an increased risk for addiction. While there is a growing body of neuroimaging literature investigating the cognitive effect of long-term cannabis use, very little is known about the potential additive effects of cannabis polysubstance use.

METHODS

Fifty-six adults composed of 18 polysubstance users (i.e., cannabis plus at least one other illicit substance), 19 cannabis-only users, and 19 nonusers completed a visuospatial attention task while undergoing magnetoencephalography. A data-driven approach was used to identify oscillatory neural responses, which were imaged using a beamforming approach. The resulting cortical regions were probed for group differences and used as seeds for whole-brain connectivity analysis.

RESULTS

Participants exhibited robust theta, alpha, beta, and gamma responses during visuospatial processing. Statistical analyses indicated that the cannabis-only group had weaker occipital theta relative to the nonusers, and that both polysubstance and cannabis-only users had reduced spontaneous gamma in the occipital cortices during the pre-stimulus baseline period relative to nonusers. Finally, functional connectivity analyses revealed that polysubstance users had sharply reduced beta connectivity between occipital and prefrontal, as well as occipital and left temporal cortices.

CONCLUSIONS

Cannabis use should be considered in a polysubstance context, as our correlational design suggests differences in functional connectivity among those who reported cannabis-only versus polysubstance use in occipital to prefrontal pathways critical to visuospatial processing and attention function. Future work should distinguish the effect of different polysubstance combinations and use more causal designs.

“I Had No Problems and Just Felt So Fabulous”: The “Storylines” of Methamphetamine Initiation in Aotearoa/New Zealand

This qualitative life course-based study analyses the key circumstances preceding methamphetamine initiation. This paper utilizes Agnew’s “storylines” concept to analyse the background and situational factors that led 42 Aotearoa/New Zealanders to initiate methamphetamine. Multiple exposure to adversity across multiple life domains placed participants at heightened risk of early-onset drug use. Preceding methamphetamine initiation, the impact of social bonds and social roles were identified within the domains of family, romantic relationships, friendship and work. Whilst drug use onset broadly follows the stage theory sequence of drug use, participants did not initiate methamphetamine until age 27 on average. Initial use typically took place in a private setting among friends, family and co-workers. The initial effect was typically very positive, which greatly contributed to escalating use. Analysis revealed four main storylines, which highlight the importance of psychological state, social bonds, romantic attachments and social functioning in methamphetamine initiation.

Effects of combined THC and heroin vapor inhalation in rats

RATIONALE

Opioids are effective medications, but they have several key limitations including the development of tolerance, establishment of dependence, diversion for non-medical use, and the development of addiction. Therefore, any drugs which act in an additive or synergistic fashion with opioids to address medical applications have the potential to reduce opioid-related harms.

OBJECTIVES

To determine if heroin and Δ9-tetrahydrocannabinol (THC) interact in an additive or independent manner to alter nociception, body temperature, and spontaneous locomotor activity when inhaled or injected.

METHODS

Groups of female and male rats, implanted with radiotelemetry transmitters, were exposed to vapor generated from heroin (50 mg/mL in propylene glycol vehicle; PG), THC (50 mg/mL), or the combination for assessment of effects on temperature and activity. Thermal nociception was assessed with a warm water tail-withdrawal assay.

RESULTS

Heroin inhalation increased temperature and activity whereas THC inhalation decreased temperature and activity in both female and male Sprague-Dawley rats. Effects of combined inhalation were in opposition, and additional experiments found the same outcome for the injection of heroin (0.5 mg/kg, s.c.) and THC (10 mg/kg, i.p.) alone and in combination. In contrast, the co-administration of heroin and THC by either inhalation or injection produced additive effects on thermal nociception in both male and female Sprague-Dawley and Wistar rats.

CONCLUSIONS

This study shows that additive effects of THC with an opioid on a medical endpoint such as analgesia may not generalize to other behavioral or physiological effects, which may be a positive outcome for unwanted side effects.

Simultaneous Alcohol and Marijuana Use Among Young Adults: A Scoping Review of Prevalence, Patterns, Psychosocial Correlates, and Consequences

BACKGROUND

Alcohol and marijuana are commonly used by young adults, and use of both substances, particularly at the same time, is prevalent among this population. Understanding the prevalence, patterns, correlates, and consequences of simultaneous alcohol and marijuana (SAM) use is important to inform interventions. However, this literature is complicated by myriad terms used to describe SAM use, including use with overlapping effects and same-day co-use.

OBJECTIVES

This scoping review identifies and describes the peer-reviewed literature focused on SAM use by young adults and distinguishes simultaneous use from same-day co-use of alcohol and marijuana. This review also provides a narrative summary of the prevalence of SAM use, patterns of SAM and other substance use, psychosocial correlates, and consequences of SAM use.

ELIGIBILITY CRITERIA

This review is limited to papers written in English and published in peer-reviewed journals between January 2000 and August 2021. It includes papers assessing simultaneous use or same-day co-use of alcohol and marijuana among young adults ages 18 to 30. Review papers, qualitative interviews, experimental lab studies, policy work, toxicology or medical reports, and papers focused on neurological outcomes are excluded.

SOURCES OF EVIDENCE

PubMed, PsycINFO, and Web of Science databases were searched. Databases were selected and the search strategy developed in consultation with an information specialist.

CHARTING METHODS

A data charting form was utilized to specify which information would be extracted from included papers. Eight categories of data were extracted: (1) research questions and hypotheses; (2) sample characteristics; (3) study procedures; (4) definition of SAM use; (5) prevalence of SAM use; (6) patterns of SAM and other substance use; (7) psychosocial correlates of SAM use; and (8) consequences of SAM use.

RESULTS

A total of 1,282 papers were identified through initial search terms. Through double-blind title/abstract screening and full-text review, the review was narrowed to 74 papers that met review inclusion criteria. Review of these papers demonstrated that SAM use was prevalent among young adults, particularly among those who reported heavier quantities and more frequent use of alcohol and marijuana. Enhancement-related motives for use were consistently positively associated with SAM use. SAM use was associated with greater perceived positive and negative consequences of alcohol and/or marijuana use. Inconsistencies in prevalence, patterns, correlates, and consequences were found between studies, which may be due to large variations in measurement of SAM use, populations studied, methodological design (e.g., cross-sectional vs. intensive longitudinal), and the covariates included in models.

CONCLUSIONS

The literature on simultaneous use and same-day co-use of alcohol and marijuana has expanded rapidly. Of the 74 included papers (61 on SAM use; 13 on same-day co-use), 60 papers (47 on SAM use; 13 on same-day co-use) were published within the last 5 years. Future research focusing on the ways in which SAM use confers acute risk, above and beyond the risks associated with separate consumption of alcohol and marijuana, is needed for understanding potential targets for intervention.

A Scoping Review of Gender, Sex and Sexuality Differences in Polysubstance Use in Adolescents and Adults

BACKGROUND

Polysubstance use is a common, problematic behavior that increases risk of harm to self and others. Research suggests that rates may vary based on gender, sex and sexuality. Understanding the current state of this literature may inform prevention and treatment of polysubstance use, leading to reduced public health burden.

OBJECTIVES

This review aimed to synthesize research on gender, sex and sexuality differences in polysubstance use in adults and adolescents.

METHODS

A scoping review was conducted using all EBSCO databases, PubMed and Google Scholar to identify articles examining the effects of gender, sex and sexuality on polysubstance use. Polysubstance use was defined broadly as the use of any combination of substances over any time period and included licit (alcohol, tobacco) and illicit substances, concurrent and simultaneous use, from lifetime to daily use and use at any frequency. Studies were considered if they were published in peer-reviewed journals between January 1990 and October 2020 and were written in English. Publicly available data sources were also utilized to fully capture prevalence data that has not been published elsewhere.

RESULTS

Findings were mostly inconsistent and often conflicting. Only two findings were generally consistent: adult men were overall more likely to report polysubstance use than adult women, and sexual and gender minorities report more frequent polysubstance use than non-minorities.

CONCLUSIONS

Research has been unable to clearly elucidate differences in polysubstance use prevalence and patterns according to gender, sex and sexuality. Several recommendations are offered to advance future research and address limitations of current research.

Towards quantifying the reciprocal associations between frequency of cannabis use and alcohol consumption: a cross-lagged analysis from the CONSTANCES cohort

OBJECTIVE

Disentangle the temporal relationships between frequency of cannabis use and alcohol consumption.

METHODS

A cross-lagged model providing standardised coefficients (SCs)±their standard errors in 13 255 men and 13 696 women enrolled in 2015 or 2016 in the French population-based 'CONSulTANts des Centres d'Examens de Santé' (CONSTANCES) cohort. Cannabis use was categorised as follows: 'No use during the past 12 months', 'Use during the past 12 months but not in the past month' and 'Use in the past month' for cannabis use at baseline, and No use during the past 12 months, 'Use less than once per month' and 'Use once per month or more' for cannabis use at 1 year of follow-up. Alcohol consumption was measured at baseline and at 1 year of follow-up and three categories were determined: low risk (<28 drinks per week in men; <14 drinks per week in women), moderate risk (≥28 and<42 in men; ≥14 and<28 in women) and high risk (≥42 in men; ≥28 in women). Analyses were adjusted for age, sex, education, income, tobacco consumption, self-rated health status and depressive symptoms.

RESULTS

Both associations from alcohol to cannabis and from cannabis to alcohol were significant (SC=0.02±0.01 with p=0.003 and SC=0.06±0.01 with p<0.001, respectively). However, the SC of the association from cannabis to alcohol was three times higher than the opposite association (p<0.001). After stratification for sex, SCs of the association from cannabis to alcohol were more than two times higher than for the opposite association in men, and more than four times higher in women (both p<0.001).

CONCLUSIONS

The association between frequency of cannabis use and subsequent alcohol consumption was stronger than the opposite association. This finding encourages considering the risk of increased alcohol consumption among cannabis users.

Polysubstance Use in Early Adulthood: Patterns and Developmental Precursors in an Urban Cohort

Polysubstance use (i.e., simultaneous or sequential use of different psychoactive substances) is associated with increases in the risk of severe health problems and social impairments. The present study leverages community-representative, long-term longitudinal data from an urban cohort to assess: (a) the prevalence and continuation of polysubstance use between adolescence and early adulthood; (b) different patterns of polysubstance use (i.e., combinations of substances) in early adulthood; and (c) childhood risk factors for polysubstance use in early adulthood. At age 20 (n = 1,180), respondents provided comprehensive self-reported information on past-year substance use, including use of legal and illicit substances (e.g., cannabinoids, stimulants, and hallucinogens), and nonmedical use of prescription drugs (e.g., opioids, tranquilizers). In adolescence (ages 13-17), limited versions of this questionnaire were administered. In childhood (ages 7-11), potential risk factors, including individual-level factors (e.g., sensation-seeking, low self-control, aggression, and internalizing symptoms) and social-environmental factors (e.g., social stressors, exposure to others' substance use), were assessed. We fitted latent class models to identify classes of participants with different substance use profiles in early adulthood. The results show that polysubstance use increased between early adolescence and early adulthood. The continuation of polysubstance use was common (stability between all adjacent assessments: odds ratio >7). At age 20, more than one-third of participants reported polysubstance use (involving illicit substances, nonmedical use of prescription drugs, and cannabidiol). Four latent classes with polysubstance use were identified: (1) broad spectrum of substances; (2) cannabis and club drugs; (3) cannabis and the nonmedical use of prescription drugs; and (4) different cannabinoids. Risk factors for any polysubstance use included childhood sensation-seeking and exposure to others' substance use; some childhood risk factors were differentially associated with the four classes (e.g., low self-control in childhood was associated with an increased likelihood of being in the broad spectrum class). The classes also differed with regard to socio-demographic factors. This study revealed that polysubstance use is a widespread and multifaceted phenomenon that typically emerges during adolescence. To facilitate the design of tailored prevention mechanisms, the heterogeneity of polysubstance use and respective socio-demographic and developmental precursors need to be considered.

Trends in binge drinking, marijuana use, illicit drug use, and polysubstance use by sexual identity in the United States (2006-2017)

Background: National studies often examine associations between sexual identity and substance use at a single point in time and neglect to examine whether these associations change over time. The present study examines U.S. trends in the past-year prevalence of binge drinking, marijuana use, illicit drug use, and polysubstance use across sexual identity subgroups (gay, lesbian, bisexual and heterosexual). Methods: The data come from four independent, cross-sectional samples measured by the National Survey of Family Growth (2006-2010, 2011-2013, 2013-2015, and 2015-2017). Based on the consistency in the sampling procedures used over time, merging the four data sets was possible. The target population is men and women 15-44 years of age. Results: Lesbian women had the sharpest decline in past-year binge drinking over time, followed by heterosexual women. The prevalence of binge drinking for bisexual women did not change significantly over time and was higher in 2015-2017 than for any sexual identity subgroup. In contrast, there were no significant differences in the prevalence of binge drinking among men by sexual identity subgroup. Past-year abstinence from substance use was consistently lower among lesbian women, gay men, and bisexual women relative to other sexual identity subgroups. Polysubstance use was consistently more prevalent among bisexual women (e.g., 32.3% in 2015-2017) as compared to other sexual identity subgroups. Conclusion: This is the first study to examine U.S. national trends in alcohol, marijuana, illicit drug, and polysubstance use across sexual identity subgroups, and demonstrates that sexual identity subgroup differences were robust with relatively few changes in trends over time. The consistently high rates of binge drinking and polysubstance use among bisexual women deserve much closer attention based on the related health consequences.

Use and abuse of dissociative and psychedelic drugs in adolescence

Adolescence is a period of profound developmental changes, which run the gamut from behavioral and neural to physiological and hormonal. It is also a time at which there is an increased propensity to engage in risk-taking and impulsive behaviors like drug use. This review examines the human and preclinical literature on adolescent drug use and its consequences, with a focus on dissociatives (PCP, ketamine, DXM), classic psychedelics (LSD, psilocybin), and MDMA. It is the case for all the substances reviewed here that very little is known about their effects in adolescent populations. An emerging aspect of the literature is that dissociatives and MDMA produce mixed reinforcing and aversive effects and that the balance between reinforcement and aversion may differ between adolescents and adults, with consequences for drug use and addiction. However, many studies have failed to directly compare adults and adolescents, which precludes definitive conclusions about these consequences. Other important areas that are largely unexplored are sex differences during adolescence and the long-term consequences of adolescent use of these substances. We provide suggestions for future work to address the gaps we identified in the literature. Given the widespread use of these drugs among adolescent users, and the potential for therapeutic use, this work will be crucial to understanding abuse potential and consequences of use in this developmental stage.

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.

Marijuana Use and Sexual Risk Behavior Among Young Black Men Who Have Sex with Men in California

Young black men who have sex with men (YBMSM) are disproportionately affected by HIV and continue to experience higher rates of new HIV infections when compared to other population groups. As part of the Peer Promotion of Wellness and Enhanced Linkage to Resources Project, we examined problem marijuana use and the overall sexual risk profile of 250 YBMSM. Eighty percent reported prior use of marijuana in their lifetime (n = 200). Among those, problem marijuana use was correlated with problem use of alcohol (r = 0.51, p < 0.001) and other drugs (r = 0.29, p < 0.001); lower household income (r = - .22, p < .01); homelessness (r = 0.15, p < 0.05); incarceration (r = 0.16, p < 0.05); exchanging sex for money, drugs, or shelter (r = 0.18, p < 0.05); having sex with someone known or suspected of having HIV and/or an STI (r = 0.20, p < 0.01); having sex with someone known or suspected of being an injector (r = 0.24, p < 0.01); and having unprotected sex while under the influence of alcohol or drugs (r = 0.32, p < 0.001). The complex relationship between marijuana and sexual risk behavior was examined while accounting for the possible moderating effects of alcohol or other drugs. Problem marijuana, alcohol, and other drug use each made unique contributions to predicting risky sex behavior. A significant marijuana and other drug interaction was found to predict sexual risk behaviors. Future efforts should include holistic intervention approaches for YBMSM that consider factors facilitating high-risk sexual behaviors.

Assessment of chromosomal aberrations among agricultural workers exposed to pesticides in Punjab, India

Chromosomal aberrations (CAs) are an important tool for assessment of exposure to pesticides. Genotoxic potential of pesticides is a principal risk factor for long-term health effects. The present study was aimed toward the assessment of CAs among agricultural workers exposed to pesticides and comparison with nonagricultural workers not exposed to pesticides. A total of 296 subjects were enrolled in the study: exposed (n = 148) and nonexposed subjects (n = 148) from Punjab. A significantly high frequency of aberrations was seen in peripheral blood lymphocytes of exposed subjects as compared with nonexposed ones. Most CAs were present as loss (aneuploidy) and were observed significantly in subjects having a history of alcohol consumption. It can be, thus, concluded that agricultural workers exposed to a mixture of pesticides, in addition to being alcoholic, are at a greater risk of genotoxic damage. It is highly recommended that the agricultural workers are educated regarding the potential hazards of occupational exposure to pesticides.

Does use of other tobacco products change when cigarette smoking status changes: A descriptive study of young adults

BACKGROUND

Whether polytobacco use or nicotine dependence (ND) change when cigarette smoking status changes in young adults is an understudied issue. Our objective was to describe use of other tobacco products (OTPs) and ND according to change in cigarette smoking status over four years in young adults.

METHODS

We drew data from a longitudinal study of 1294 adolescents age 12-13 at inception in 1999-2000 and followed into young adulthood. Among 790 participants with data at age 20 and 24, 22% had never smoked cigarettes; 37% were "sustained smokers"; 9% were "relapsers"; 10% had quit 1-3 years ago; and 22% had quit ≥4 years ago. We described past-year OTP (i.e., cigars/cigarillos, waterpipe, sundry tobacco products (i.e., pipe, bidis, chewing tobacco, snuff)) use and ND over 4 years in these groups.

RESULTS

At age 20, sustained smokers reported using a mean(SD) of 1.1(0.9) OTP in the past-year; relapsers reported 0.5(0.6); shorter-term quitters reported 0.9(0.7); longer-term quitters reported 0.3(0.6); and never smokers reported 0.2(0.4). There was no change in OTP use or ND in never smokers and longer-term quitters. Shorter-term quitters reduced the number of OTPs by -0.5(95% confidence interval: -0.7,-0.3) on average over 4 years; sustained smokers decreased by -0.2(-0.3,-0.1). Relapsers increased by 0.6(0.4,0.7) on average.

CONCLUSIONS

OTP use and ND were stable in early adulthood among never smokers, sustained smokers and longer-term quitters, but fluctuated in parallel with stopping and starting to smoke. Research is needed to ascertain the underpinnings of these fluctuations and whether they help or hinder cessation.

Examining the Utility of a General Substance Use Spectrum Using Latent Trait Modeling

BACKGROUND

Polysubstance use (PSU; lifetime use of multiple substances) is common among individuals with problematic alcohol/substance use and is associated with poor prognosis and poor physical/mental health. Furthermore, simultaneous co-use of substances, such that drug effects overlap, is also common and related to unique risks (e.g. overdose). Despite the importance of PSU, current diagnostic systems continue to conceptualize problems with alcohol/substances as class-specific constructs (e.g. Stimulant Use Disorder), which essentially ignore many unique PSU processes.

METHODS

The current study modeled problems with alcohol, cannabis, stimulants, sedatives, opiates, and simultaneous co-use of these substances as a manifestation of a general substance use continuum versus as correlated class-specific constructs in a sample of young-adults(n = 2482) using confirmatory factor analysis. Utility of the models was evaluated by examining associations between the general substance use spectrum and class-specific latent factors with measures of anxiety, ADHD, adult antisocial problems, borderline symptoms, neuroticism, and intelligence in a subset of the sample(n=847).

RESULTS

Findings supported the conceptualization of problems with all substances, including co-use of substances, as being manifestations of a general substance use spectrum, as class-specific constructs were not differentially associated with other measures of psychological dysfunction. Examination of this general substance use spectrum indicated that all substances, separately and co-use, were robustly informative of this spectrum, but tended to discriminate between different severity levels.

DISCUSSION

The general substance use spectrum allows for integration of information from the use and co-use of all substances to provide better assessment of overall problems with substances compared to class-specific constructs.

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.

OREX-1019: A Novel Treatment of Opioid Use Disorder and Relapse Prevention

There is an urgent need for new pharmacological treatments for substance use disorders, including opioid use disorder, particularly for use in relapse prevention. A combination of buprenorphine with naltrexone has shown particular promise, with clinical studies indicating a substantial improvement over treatment with naltrexone alone. OREX-1019 (formerly BU10119) is a compound that mimics the pharmacology of the buprenorphine/naltrexone combination. This study evaluated, in rhesus monkeys, the therapeutic potential of OREX-1019 for treating opioid use disorder. Pretreatment with OREX-1019 (0.01-0.3 mg/kg s.c.) dose-dependently decreased responding for the μ opioid receptor agonist remifentanil in rhesus monkeys but did not maintain levels of responding above vehicle when it was available for self-administration. OREX-1019 (0.01-1.0 mg/kg s.c.) also decreased cue- plus heroin-primed reinstatement of extinguished responding in monkeys that self-administered remifentanil but did not alter cue- plus cocaine-primed reinstatement of responding in monkeys that self-administered cocaine. OREX-1019 (0.3 mg/kg s.c.), like naltrexone (0.1 mg/kg s.c.), increased heart rate and blood pressure, produced overt observable signs, and eliminated food-maintained responding in monkeys treated chronically with morphine. These results confirm that OREX-1019 has little or no efficacy at μ opioid receptorsand has low abuse potential, and, combined with promising safety (clean profile vs. other off-target proteins including the hERG (human ether-a-go-go-related gene) K⁺ channel) and pharmacokinetic data (supporting administration by subcutaneous or sublingual routes, but with low oral bioavailability), suggest it could be a safe and effective alternative to current treatments for opioid use disorders particularly as applied to relapse prevention. SIGNIFICANCE STATEMENT: The novel opioid OREX-1019 potentially provides an improved relapse prevention agent for use in opioid use disorder. The current study demonstrates that in monkeys OREX-1019 is able to inhibit the self-administration of, and cue- plus heroin-primed reinstatement of, responding previously maintained by remifentanil.

Multidisciplinary team actions of a Brazilian Psychosocial Care Center for Alcohol and Drugs

OBJECTIVE

to investigate the criteria used by health professionals to identify the phase of consumption of alcohol and drug users, and actions directed to their care.

METHOD

a qualitative study developed with 14 professionals from a Brazilian Psychosocial Care Center for Alcohol and Drugs (Centro de Atenção Psicossocial Álcool e Drogas) based in the south of the country. Data were collected in June 2017 through semi-structured interviews and then submitted to thematic analysis.

RESULTS

the criteria used by the professionals were: periodicity of use; amount and type of drug used; repercussions of misuse; and place that the drug occupies in the person's life. The actions developed were orientation and referral to support groups, therapeutic workshops and individual care.

FINAL CONSIDERATIONS

the chronic nature of alcohol/drug use/dependence requires specific care in each phase, and objective criteria to identify and intervene in early phases, aiming at the prevention of chemical dependence.

Acute and long-term cannabis use among stimulant users: Results from CTN-0037 Stimulant Reduction Intervention using Dosed Exercise (STRIDE) Randomized Control Trial

AIMS

The aim of this study was to examine the impact of vigorous intensity, high dose exercise (DEI) on cannabis use among stimulant users compared to a health education intervention (HEI) using data from the Stimulant Reduction Intervention using Dosed Exercise, National Institute of Drug Abuse National Drug Treatment Clinical Trials Network Protocol Number 0037 (STRIDE).

METHODS

Adults (N = 302) enrolled in the STRIDE randomized clinical trial were randomized to either the DEI or the HEI. Interventions included supervised sessions three times a week during the Acute phase (12 weeks) and once a week during the Follow-up phase (6 months). Cannabis use was measured at each assessment via Timeline Follow Back and urine drug screens. Cannabis use was compared between the groups during the Acute and Follow-up phases using both the intent-to-treat sample and a complier average causal effects (CACE) analysis.

FINDINGS

Approximately 43% of the sample reported cannabis use at baseline. The difference in cannabis use between the DEI and HEI groups during the Acute phase was not significant. During the Follow-up phase, the days of cannabis use was significantly lower among those in the DEI group (1.20 days) compared to the HEI group (2.15 days; p = 0.04).

CONCLUSIONS

For those who adhered to the exercise intervention, vigorous intensity, high dose exercise resulted in less cannabis use. Results suggest that there were no significant short-term differences in cannabis use between the groups. Further study on the long-term impact of exercise as a treatment to reduce cannabis use should be considered.

Alcohol, tobacco, and marijuana consumption is associated with increased odds of same-day substance co- and tri-use

BACKGROUND

Little is known about event-level patterns of marijuana co- or tri-use with alcohol and tobacco. Thus, the study goal was to examine patterns of same-day alcohol, cigarette, and marijuana co- and tri-use at the individual level in non-treatment-seeking alcohol users.

METHODS

Participants (N = 551) completed an in-person interview for alcohol, cigarette, and marijuana use over the previous 30 days, and the event-level substance use patterns of n = 179 participants who reported using each of these substances at least once per month were analyzed.

RESULTS

The use of alcohol, marijuana, or cigarettes independently increased the probability of subsequent, simultaneous co-use of one of the two remaining substances. The co-use of alcohol with cigarettes and marijuana with cigarettes produced generally additive effects on the odds of same day tri-use of marijuana and alcohol, respectively. Conversely, the co-use of alcohol and marijuana produced sub-additive effects on likelihood of cigarette use. Sex moderated several of the observed patterns of co- and tri-use: the relationship between alcohol or cigarette use predicting marijuana co-use was stronger in men, whereas the observed additive relationships between drug co-use leading to tri-use was stronger in women.

CONCLUSIONS

The presented results may aid in the understanding of how simultaneous co-use of marijuana with alcohol and/or tobacco relates to the etiology, maintenance, and treatment of comorbid and trimorbid substance use disorder. Replication and extension of the results in treatment seeking populations using more fine-grained analysis approaches, e.g. ecological momentary assessment, is needed.

Context matters: Characteristics of solitary versus social cannabis use

INTRODUCTION AND AIMS

Given the increase in cannabis availability and use in North America, identification of risk factors for cannabis use and dependence is paramount. One factor that may be associated with various cannabis-related adverse outcomes is the context in which it is used. This secondary analysis study sought to examine the extent to which the social context of cannabis use is related to patterns of use and associated harms.

DESIGN AND METHODS

One hundred and eighty-eight adult cannabis users were community-recruited in Halifax, Canada. Participants took part in a face-to-face structured interview where they provided information about the social context of their most recent cannabis-using occasion and about their patterns of, and motives for, cannabis use.

RESULTS

Compared to individuals reporting their most recent cannabis-using occasion as social, solitary users (n = 55) were significantly more likely to screen positive for psychosis, endorse more symptoms of cannabis abuse/dependence, report using cannabis to cope, and use cannabis on more days within the previous 30 days. On the other hand, social users were significantly more likely to report using alcohol in addition to cannabis during their most recent cannabis-using occasion (all P < 0.05).

DISCUSSION AND CONCLUSIONS

Results suggest that solitary cannabis use may be associated with specific motives for use and future adverse consequences. Findings from this study serve as a guide for future investigations which could ultimately inform public policy and the development of targeted harm-reduction strategies.

The importance of considering polysubstance use: lessons from cocaine research

BACKGROUND

Polysubstance use (PSU) is prevalent among individuals with substance use disorders, but the vast majority of preclinical substance use research has focused on individual substances in isolation. Cocaine has been prevalent in the repertoire of persons who use more than one illicit substance.

METHODS

We conducted a meta-analysis combining results from literature searches and secondary data analyses to estimate the prevalence of simultaneous and concurrent cocaine + alcohol and cocaine + cannabis use among cocaine users. We next summarized the small body of literature on behavioral, cognitive and neurobiological consequences of cocaine PSU across species, with a focus on alcohol and cannabis. Finally, we used systematic literature searches to assess the extent to which human and animal studies on the neurobiological consequences of cocaine include PSU subjects.

RESULTS

The estimated prevalence of simultaneous and concurrent alcohol use among human cocaine users was 74% and 77%, respectively. The estimated prevalence of simultaneous and concurrent cannabis use among cocaine users was 38% and 64%, respectively. Consumption of alcohol or cannabis with cocaine enhances subjective responses to cocaine, concomitant with changes in cocaine metabolism that increase blood cocaine levels, and, in the case of alcohol, produce the psychoactive metabolite cocaethylene. There is also consistent evidence for neurobiological effects of cocaine + alcohol combinations. However, animal PSU research with cocaine lags behind human research.

CONCLUSION

Based on the prevalence and known consequences of PSU, consideration of PSU in both human and animal research is vital for understanding patterns of substance use.

Correlates and trends in youth co-use of marijuana and tobacco in the United States, 2005-2014

BACKGROUND

Past-month marijuana and tobacco use (co-use) are increasing among U.S. adults, but little is known about the prevalence of co-use among U.S. youth. This study uses nationally representative data to assess the prevalence, correlates, and trends in co-use of marijuana and tobacco, tobacco-only use, and marijuana-only use among U.S. youth.

METHODS

Data came from 176,245 youth ages 12-17 who responded to the National Survey on Drug Use and Health - a nationally representative, household interview survey - between 2005 and 2014. Prevalence, demographics and substance use characteristics from 2013 to 14 were assessed across three groups: past-month users of marijuana and tobacco (co-users), past-month tobacco-only users, and past-month marijuana-only users. Multinomial logistic regression was used to assess demographic correlates of each group. Linear and quadratic trends were assessed from 2005 to 2014 using logistic regression with orthogonal polynomials.

RESULTS

In 2013-14, 5.4% of youth reported past-month co-use of tobacco and marijuana, 2.2% reported marijuana-only use, and 3.9% reported tobacco-only use. Co-use was associated with higher prevalence of past year marijuana dependence (vs. marijuana-only users), and higher past-month risky alcohol and other illicit drug use (vs. both tobacco and marijuana-only use groups). Co-use did not increase significantly between 2005 and 2014; tobacco-only use declined, and marijuana-only use increased.

CONCLUSIONS

Co-use of marijuana and tobacco is more prevalent than tobacco-only or marijuana-only use in U.S. youth. Given changing tobacco and marijuana policies, ongoing surveillance and studies that seek to increase our understanding of co-use behaviors in youth are critical.

Places and social contexts associated with simultaneous use of alcohol, tobacco and marijuana among young adults

INTRODUCTION AND AIMS

Little is known about social-ecological correlates of simultaneous use of alcohol with other substances. This study examined places and social contexts associated with simultaneous use of alcohol, tobacco and marijuana among young adults.

DESIGN AND METHODS

We used survey data obtained from 1538 young adult recent alcohol drinkers (49% male; 18-30 years old) in 24 non-contiguous cities in California. Event-level measures included alcohol, tobacco and marijuana use, drinking places and social characteristics of the event. Individual-level measures included alcohol expectancies, depression and demographics.

RESULTS

Bars and restaurants had less alcohol and marijuana use (odds ratio = 0.34; 95% confidence interval 0.18, 0.62; P < 0.001) and alcohol, marijuana and tobacco use (odds ratio = 0.27; 95% confidence interval 0.14, 0.54; P < 0.001) compared with alcohol use only. Perceived percent of intoxicated people at an event was associated with greater likelihood of using alcohol with tobacco and marijuana at the event. At the individual level, greater age was generally associated with increased odds of simultaneous use. Participants who were male, less educated, more depressed and had positive alcohol expectancies were more likely to simultaneously co-use alcohol with tobacco and marijuana. Those with negative expectancies were less likely to simultaneously use these substances.

DISCUSSION AND CONCLUSIONS

Social events in private settings with a high percentage of people who are intoxicated had increased likelihood of simultaneous use of alcohol, tobacco and marijuana. Prevention efforts in these settings may reduce simultaneous use of these substances and related harms. [Lipperman-Kreda S, Paschall MJ, Saltz RF, Morrison CN. Places and social contexts associated with simultaneous use of alcohol, tobacco and marijuana among young adults. Drug Alcohol Rev 2017;00:000-000].

Marijuana use among adults: Initiation, return to use, and continued use versus quitting over a one-year follow-up period

BACKGROUND

This study examined factors associated with marijuana use initiation among never users, prior-to-past year user who return to use, and users who continue use over a 12-month follow-up period.

METHODS

Two waves (W1 and W2) of the Population Assessment of Tobacco and Health (PATH) Study provided data (N=26,204 aged 18+). Multivariable logistic regression models were used to examine associations of W1 sociodemographic, health/mental health, and other substance use characteristics with W2 use status. As applicable, marijuana initiation age, use frequency, and use problems were also examined.

RESULTS

At W2, 2.36% and 10.42% of W1 never users and prior-to-past year users, respectively, reported having used marijuana, and 72.54% of W1 past-year users reported continued use. Those in the 18-24 age group were most likely to initiate, resume, or continue use. Among never and prior-to-past year users, those who reported more mental health problems at W1 also had greater odds of use at W2. Marijuana initiation and return to use were significantly associated with movement from nonuse to use of other substances. Continued marijuana use, as opposed to quitting, was also associated with other substance use, initiation of marijuana use prior to age 18, weekly or more frequent use (AOR=2.34, 95% CI=1.87-2.93), and use problems (AOR=1.40, 95% CI=1.05-1.85) reported at W1.

CONCLUSIONS

Movement between marijuana nonuse and use was substantial during the 12-month follow-up period. Early intervention to prevent initiation of, return to, and continued marijuana and other substance use, especially among young adults, is needed.

Preclinical Studies of Cannabinoid Reward, Treatments for Cannabis Use Disorder, and Addiction-Related Effects of Cannabinoid Exposure

Cannabis use has become increasingly accepted socially and legally, for both recreational and medicinal purposes. Without reliable information about the effects of cannabis, people cannot make informed decisions regarding its use. Like alcohol and tobacco, cannabis can have serious adverse effects on health, and some people have difficulty discontinuing their use of the drug. Many cannabis users progress to using and becoming addicted to other drugs, but the reasons for this progression are unclear. The natural cannabinoid system of the brain is complex and involved in many functions, including brain development, reward, emotion, and cognition. Animal research provides an objective and controlled means of obtaining information about: (1) how cannabis affects the brain and behavior, (2) whether medications can be developed to treat cannabis use disorder, and (3) whether cannabis might produce lasting changes in the brain that increase the likelihood of becoming addicted to other drugs. This review explains the tactics used to address these issues, evaluates the progress that has been made, and offers some directions for future research.

Multiple DSM-5 substance use disorders: A national study of US adults

OBJECTIVE

Our aim is to determine the lifetime and past-year prevalence estimates of multiple Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5) substance use disorders (SUDs) among U.S. adults.

METHODS

The 2012-2013 National Epidemiologic Survey on Alcohol and Related Conditions featured in-person interviews with a nationally representative sample of adults aged 18 and older.

RESULTS

The majority of past-year nonalcohol DSM-5 SUDs had at least 1 other co-occurring past-year SUD, ranging from 56.8% (SE = 3.4) for past-year prescription opioid use disorder to 97.5% (SE = 2.7) for past-year hallucinogen use disorder. In contrast, only 15.0% (SE = 0.6) of past-year alcohol use disorders had a co-occurring past-year SUD. The odds of past-year multiple SUDs were greater among males, younger adults, African-Americans, and those with mood, personality, posttraumatic stress, or multiple psychiatric disorders.

CONCLUSIONS

Assessment, diagnosis, and treatment often focus on individual substance-specific SUDs rather than multiple SUDs, despite evidence for substantial rates of polysubstance use in clinical and epidemiological studies. There are notable differences in the prevalence of multiple SUDs between alcohol use disorders and other nonalcohol SUDs that have important clinical implications; for example, multiple SUDs are more persistent than individual SUDs. These findings suggest that clinical assessment and diagnosis should screen for multiple SUDs, especially among adults with nonalcohol DSM-5 SUDs.

The 3-Year Course of Multiple Substance Use Disorders in the United States: A National Longitudinal Study

OBJECTIVE

To examine the 3-year course of multiple co-occurring substance use disorders (SUDs) based on longitudinal survey data from a large, nationally representative sample.

METHODS

National estimates of the prevalence of DSM-IV SUDs were derived by analyzing data from structured, face-to-face diagnostic interviews as part of the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC), which collected data from a large, nationally representative sample of noninstitutionalized US adults at 2 waves (2001-2002 and 2004-2005; N = 34,653).

RESULTS

US adults with multiple past-year SUDs at Wave 1 were substantially more likely than those with an individual past-year SUD or no SUD at Wave 1 to report at least 1 past-year SUD at Wave 2 (66.3% vs 46.0% vs 6.9%, respectively). There were several sociodemographic characteristics and psychiatric disorders (ie, male, younger age, never married, sexual minority identity, nicotine dependence, mood disorder, and personality disorder) associated with increased odds of developing multiple SUDs and having 3-year persistence of multiple SUDs. The majority of adults with multiple past-year SUDs had a lifetime personality disorder and did not utilize substance abuse treatment or other help-seeking.

CONCLUSIONS

Multiple SUDs are associated with a more persistent 3-year course of disease over time relative to individual SUDs. Despite a more severe 3-year course and higher rates of comorbidity with other psychiatric disorders, the majority of US adults with multiple SUDs do not utilize substance abuse treatment or other help-seeking. Clinical assessments and the substance abuse literature tend to focus on drug-specific individual SUDs rather than considering the more complex multiple SUDs, which can be more challenging to treat.

Long-term cognitive, emotional and neurogenic alterations induced by alcohol and methamphetamine exposure in adolescent rats

A high proportion of young methamphetamine (MA) users simultaneously consume alcohol. However, the potential neurological and behavioural alterations induced by such a drug combination have not been systematically examined. We studied in adolescent rats the long-term effects of alcohol, MA, and alcohol and MA combined on anxiety-like behaviour, memory, and neurogenesis in the adult hippocampus. Rats received saline, ethanol (ETOH, 1.5g/kg), MA (MA, 2mg/kg), or ethanol and MA combined (ETHOH-MA, 1.5g/kg ethanol plus 2mg/kg MA) via oral gavage, once daily for 5 consecutive days. Open field (OF), elevated plus maze (EPM) and radial arm maze (RAM) tests were conducted following a 15-day withdrawal period. The results showed alterations in exploratory behaviour in the OF in the MA and ETOH-MA groups, and anxiety-like effects in the EPM in all three drug treatment groups. All three drug groups exhibited reference memory deficits in the RAM, but only the combination treatment group displayed alterations in working memory. Both MA and ETOH-MA treatments increased the length of doublecortin (DCX)-void gaps in the dentate gyrus but only ETOH-MA treatment increased the number of such gaps. An increased number and length of DCX-void gaps correlated with decreased exploratory activity in the OF, and impaired working memory in the RAM was associated with an augmented number of gaps. These findings suggest that alterations in adult hippocampal neurogenesis are linked to the persistent cognitive and behavioural deficits produced by alcohol and MA exposure.

Persistency of Cannabis Use Predicts Violence following Acute Psychiatric Discharge

BACKGROUND

Violence is a major concern and is prevalent across several mental disorders. The use of substances has been associated with an exacerbation of psychiatric symptoms as well as with violence. Compared to other substances such as alcohol and cocaine, existing literature on the cannabis-violence relationship has been more limited, with most studies being conducted in the general population, and has shown controversial results. Evidence has suggested a stronger relationship when examining the effects of the persistency of cannabis use on future violent behaviors. Though, while cannabis use is highly prevalent amid psychiatric patients, far less literature on the subject has been conducted in this population. Hence, the present prospective study aims to investigate the persistency of cannabis use in psychiatric patients.

METHOD

The sample comprised of 1,136 recently discharged psychiatric patients provided by the MacArthur Risk Assessment Study. A multi-wave (five-assessment) follow-up design was employed to allow temporal sequencing between substance use and violent behaviors. Generalized estimating equations (GEE) were used to examine the effect of persistency of cannabis use on violence, while controlling for potential confounding factors. Potential bidirectional association was also investigated using the same statistical approach.

RESULTS

Our results suggest a unidirectional association between cannabis use and violence. GEE model revealed that the continuity of cannabis use across more than one time wave was associated with increased risks of future violent behavior. Patients who reported having used cannabis at each follow-up periods were 2.44 times more likely to display violent behaviors (OR = 2.44, 95% CI: 1.06-5.63, p < 0.05).

CONCLUSION

These findings are particularly relevant as they suggest that the longer individuals report having used cannabis after a psychiatric discharge, the more likely they are of being violent in the following time waves. These results add to our understanding of the negative consequences of chronic cannabis use amid psychiatric patients.

Experiences of Health Professionals Caring for People Presenting to the Emergency Department After Taking Crystal Methamphetamine ("ICE")

Globally, addiction to "ICE" (crystal methamphetamine) is increasing and presents emergency health care services personnel with a number of challenges. This paper reports the first of two major themes arising from a qualitative study investigating health professionals' experiences' managing people presenting to the Emergency Department (ED) after taking "ICE." The theme "Caring for people who use 'ICE' when presenting to EDs" comprises five subthemes. These are: (a) expecting the unexpected: "they're just off their heads"; (b) complexity of care: "underlying trauma and emotional dysregulation";

Gender Differences in the Association Between Religion/Spirituality and Simultaneous Polysubstance Use (SPU)

While religion/spirituality strongly protects against drug use (Cheney et al. in J Drug Issues 44(1):94-113, 2014), little is known about gender differences in the association of religion/spirituality on simultaneous polysubstance use (SPU) among those who use prescription opioids. Data come from a community-based study that recruited community members from the St Louis area (N = 632). Participants were asked whether they used prescription opioids when not prescribed for them or in ways other than prescribed in the past 12 months. Religion/spirituality was categorized as high, medium, or low based on personal views on the importance of religion and spirituality, attendance at religious services, and advice seeking from religious leaders. SPU was defined as non-medical use of opioids simultaneously with use of cocaine, alcohol, ecstasy, or marijuana. Multivariate logistic regression determined the association between religion/spirituality, demographic variables, and SPU. Men with high levels of religion/spirituality had 63 % decreased odds of SPU compared with men with low levels. Other variables associated with SPU in men were four or more arrests (AOR 2.21), multiple sex partners (AOR 2.11), and opioid use without a prescription (AOR 3.04). Women with high or medium levels of religion/spirituality had 58 and 62 % decreased odds of SPU compared with women with low levels. Variables that predicted SPU in women also included 4+ arrests (AOR 5.00) and never being married (AOR 2.13). Being African-American was associated with decreased odds of SPU in women (AOR 0.32). Overall, a high level of religion/spirituality was associated with lower odds of SPU. Gender differences in this association were evident, whereas women with even a medium level of religion/spirituality had significantly decreased odds of SPU. Future drug prevention and interventions should consider the relevance of religion/spirituality in SPU.

Marijuana and Other Substance Use Among Motor Vehicle Operators: A Latent Class Analysis

OBJECTIVE

The deleterious effect of multiple-substance use on driving performance is well established, but relatively little research has examined the patterns of drug use among multiple-substance users and its relationship to both alcohol use and adverse driving outcomes.

METHOD

The current study used latent class analysis to examine subgroups of substance users among a population of drivers who screened positively for 2 or more of 13 substances other than alcohol (N = 250). A series of logistic regression analyses was conducted to examine demographic predictors of latent class assignment and class association with adverse driving outcomes.

RESULTS

Four distinct subclasses of users were identified among multiple-substance-using drivers: Class 1 consisted of individuals who demonstrated high levels of all substances indicators (5%). The second class demonstrated high levels of marijuana and cocaine use and lower levels of all other substances (27%). The third class screened high for marijuana and nonmedical prescription opiate analgesics use (36%), whereas the last class demonstrated high nonmedical prescription opiate analgesics and benzodiazepine use (32%). Drivers in Class 2 (marijuana and cocaine users) were more likely to be younger and have a positive breath alcohol concentration than drivers in any other class.

CONCLUSIONS

Because multidrug users show dissimilar characteristics, the propensity of researchers to lump all multiple-substance users together may either erroneously attribute the potentially profound impact of those in the marijuana and cocaine use class to all multiple-substance users or dilute their specific contribution to crash risk.

Managing Chronic Pain in Special Populations with Emphasis on Pediatric, Geriatric, and Drug Abuser Populations

In the adult population chronic pain can lead to loss of productivity and earning potential, and decreased quality of life. There are distinct groups with increased vulnerability for the emergence of chronic pain. These groups may be defined by developmental status and/or life circumstances. Within the pediatric, geriatric, and drug abuser populations, chronic pain represents a significant health issue. This article focuses on known anatomic, physiologic, and genetic mechanisms underlying chronic pain in these populations, and highlights the need for a multimodal approach from multiple health care professionals for management of chronic pain in those with the most risk.

Prevalence and correlates of co-ingestion of prescription tranquilizers and other psychoactive substances by U.S. high school seniors: Results from a national survey

INTRODUCTION

Nonmedical tranquilizer use (NMTU) is a concerning and understudied phenomenon in adolescents, despite being the second most prevalent form of nonmedical use in this population. Thus, this work aimed to examine the sociodemographic and substance use correlates of past-year co-ingestion of a prescription tranquilizer and another substance among adolescents.

METHODS

Data were from the Monitoring the Future study, a nationally representative survey of U.S. high school students. Data from 11,444 seniors (12th graders) completing form 1 of the survey were used. The participants represented a population that was 52.7% female, 61.8% White, and had a modal age of 18. Weighted frequencies and Rao-Scott chi-square analyses were computed to describe the target population and examine associations of interest.

RESULTS

An estimated 5.3% of the population engaged in past-year NMTU during this time period, with an estimated 72.6% of those users engaged in past-year co-ingestion of a tranquilizer and another substance. Marijuana and alcohol were the most commonly co-ingested substances. Those engaged in co-ingestion were more likely than past-year nonmedical users without co-ingestion to be engaged in other substance or nonmedical use (including past year nonmedical Xanax® (alprazolam) use), have an earlier onset of NMTU, and endorse recreational motives.

CONCLUSIONS

Adolescent nonmedical tranquilizer users engaged in co-ingestion may be a particularly vulnerable population, with higher rates of other substance use, other nonmedical use and problematic NMTU characteristics than nonmedical users without co-ingestion. Identification of and intervention with adolescent co-ingestion users are important avenues for future research and clinical practice.

White matter deficits assessed by diffusion tensor imaging and cognitive dysfunction in psychostimulant users with comorbid human immunodeficiency virus infection

BACKGROUND

Psychostimulant drug use is commonly associated with drug-related infection, including the human immunodeficiency virus (HIV). Both psychostimulant use and HIV infection are known to damage brain white matter and impair cognition. To date, no study has examined white matter integrity using magnetic resonance imaging (MRI) diffusion tensor imaging (DTI) in chronic psychostimulant users with comorbid HIV infection, and determined the relationship of white matter integrity to cognitive function.

METHODS

Twenty-one subjects (mean age 37.5 ± 9.0 years) with a history of heavy psychostimulant use and HIV infection (8.7 ± 4.3 years) and 22 matched controls were scanned on a 3T MRI. Fractional anisotropy (FA) values were calculated with DTI software. Four regions of interest were manually segmented, including the genu of the corpus callosum, left and right anterior limbs of the internal capsule, and the anterior commissure. Subjects also completed a neurocognitive battery and questionnaires about physical and mental health.

RESULTS

The psychostimulant using, HIV positive group displayed decreased white matter integrity, with significantly lower FA values for all white matter tracts (p < 0.05). This group also exhibited decreased cognitive performance on tasks that assessed cognitive set-shifting, fine motor speed and verbal memory. FA values for the white matter tracts correlated with cognitive performance on many of the neurocognitive tests.

CONCLUSIONS

White matter integrity was thus impaired in subjects with psychostimulant use and comorbid HIV infection, which predicted worsened cognitive performance on a range of tests. Further study on this medical comorbidity is required.

Progression to regular heroin use: examination of patterns, predictors, and consequences

BACKGROUND

The present study retrospectively evaluated the chronology and predictors of substance use progression in current heroin-using individuals.

METHODS

Out-of-treatment heroin users (urinalysis-verified; N=562) were screened for laboratory-based research studies using questionnaires and urinalysis. Comprehensive substance use histories were collected. Between- and within-substance use progression was analyzed using stepwise linear regression models.

RESULTS

The strongest predictor of onset of regular heroin use was age at initial heroin use, accounting for 71.8% of variance. The strongest between-substance predictors of regular heroin use were ages at regular alcohol and tobacco use, accounting for 8.1% of variance. Earlier onset of regular heroin use (≤20 years) vs. older onset (≥30 years) was associated with a more rapid progression from initial to regular use, longer duration of heroin use, more lifetime use-related negative consequences, and greater likelihood of injecting heroin. The majority of participants (79.7%) reported substance use progression consistent with the gateway hypothesis. Gateway-inconsistent individuals were more likely to be African-American and to report younger age at initial use, longer duration of heroin use, and more frequent past-month heroin use.

CONCLUSIONS

Our findings demonstrate the predictive validity and clinical relevance of evaluating substance use chronology and the gateway hypothesis pattern of progression.

Simultaneous co-ingestion of prescription stimulants, alcohol and other drugs: a multi-cohort national study of US adolescents

OBJECTIVE

To determine the past-year prevalence rates and correlates of simultaneous co-ingestion of prescription stimulants and other substances among US high school seniors.

METHODS

Nationally representative probability samples of US high school seniors were surveyed as a part of the Monitoring the Future study. The sample consisted of five cohorts including a total of 12,431 high school seniors (modal age: 18 years) and represented a population that was 53% female.

RESULTS

Among past-year nonmedical users of prescription stimulants (n = 835), the estimated prevalence of any past-year simultaneous co-ingestion of prescription stimulants and other substances was 64.4%. The substances most commonly co-ingested with prescription stimulants included marijuana (51.1%) and alcohol (48.4%). Nonmedical users who co-ingested prescription stimulants with other substances were more likely to report non-oral routes of administration, recreational motives and greater subjective high when using prescription stimulants than nonmedical users who did not co-ingest prescription stimulants with other substances.

CONCLUSIONS

The majority of past-year nonmedical users of prescription stimulants reported simultaneous co-ingestion of prescription stimulants and other substances. The findings indicate that co-ingestion of prescription stimulants and other substances is a pervasive behavior among US adolescents who engage in nonmedical use of prescription stimulants and should be carefully considered in future clinical practice and research.

Neurocognitive Profiles of Methamphetamine Users: Comparison of Those With or Without Concomitant Ketamine Use

OBJECTIVE

Methamphetamine (MAMP) and ketamine are neurotoxic drugs whose chronic use has been linked with a cognitive decline in some users. This paper aims to assess the possible effect of concomitant ketamine use on the neurocognitive performance of MAMP users.

METHODS

This study divides 42 MAMP users into MAMP users who use ketamine (MAMP+K, n = 16) and MAMP users who do not use ketamine (MAMP-K, n = 26). The performance of these two groups was compared using the Brief Assessment of Cognition in Schizophrenia (BACS), Conners' Continuous Performance Tests (CPT), the Wisconsin Card Sorting Test (WCST), the Iowa Gambling Task (IGT), and the Barratt Impulsiveness Scale (BIS).

RESULTS

In comparison to the MAMP-K group, the MAMP+K group showed worse performances in verbal fluency, executive function and composite score in BACS; worse performances in total errors, perseverative errors, nonperseverative errors and conceptual level response in WCST; and greater levels of total scores and novelty-seeking in BIS. Neither the attention function evaluated with CPT nor the decision-making behavior evaluated with IGT was associated with previous ketamine use.

CONCLUSION

This study detected worse executive function and higher impulsivity level among MAMP users with additional ketamine use versus their counterparts without ketamine use. Further studies with a longitudinal design and a large sample size are necessary to clarify the connection between cognitive deficits and concomitant use of MAMP and ketamine.

Social Influence on Adolescent Polysubstance Use: The Escalation to Opioid Use

BACKGROUND

Fewer than 9% of 12-17 year olds in need (∼146,000 of 1.7 million) receive inpatient or outpatient substance abuse recovery services or other mental health services (SAMHSA, 2012). The literature on adolescent addiction is sparse, however, as most published addiction recovery efforts involve adult populations-often college students.

OBJECTIVES

The present study examined social influences on escalating substance use (from tobacco, alcohol, and marijuana use to polysubstance use involving opioids) for students enrolled in recovery high schools.

METHODS

A sample of 31 adolescents enrolled in substance use recovery high schools were surveyed on their patterns of substance use leading to their abuse of opioids.

RESULTS

Youth who begin their substance use as young as age 8 are often pressured by peer culture to do so and come from substance-using families. Their escalation in polysubstance use to a pattern including opioids was also most often attributed to peer influence over several years. Conclusions/Importance: This paper is one of scant few that address patterns of use in high school students. Perhaps most salient from this study are the tertiary prevention implications: similar to their adult counterparts, students enrolled in recovery high school programs are likely from substance-using families and have combined complex constellations of substances including opioids by dint of their relationships with substance-using peers.

Identifying patients with problematic drug use in the emergency department: results of a multisite study

STUDY OBJECTIVE

Drug-related emergency department (ED) visits have steadily increased, with substance users relying heavily on the ED for medical care. The present study aims to identify clinical correlates of problematic drug use that would facilitate identification of ED patients in need of substance use treatment.

METHODS

Using previously validated tests, 15,224 adult ED patients across 6 academic institutions were prescreened for drug use as part of a large randomized prospective trial. Data for 3,240 participants who reported drug use in the past 30 days were included. Self-reported variables related to demographics, substance use, and ED visit were examined to determine their correlative value for problematic drug use.

RESULTS

Of the 3,240 patients, 2,084 (64.3%) met criteria for problematic drug use (Drug Abuse Screening Test score ≥ 3). Age greater than or equal to 30 years, tobacco smoking, daily or binge alcohol drinking, daily drug use, primary noncannabis drug use, resource-intense ED triage level, and perceived drug-relatedness of ED visit were highly correlated with problematic drug use. Among primary cannabis users, correlates of problematic drug use were age younger than 30 years, tobacco smoking, binge drinking, daily drug use, and perceived relatedness of the ED visit to drug use.

CONCLUSION

Clinical correlates of drug use problems may assist the identification of ED patients who would benefit from comprehensive screening, intervention, and referral to treatment. A clinical decision rule is proposed. The correlation between problematic drug use and resource-intense ED triage levels suggests that ED-based efforts to reduce the unmet need for substance use treatment may help decrease overall health care costs.

Comparison of antidepressant-like and abuse-related effects of phencyclidine in rats

Preclinical Research N-methyl-D-aspartate (NMDA) receptor antagonists, such as ketamine, have emerged as novel candidate treatments for major depressive disorder, but abuse potential of these agents is a concern. The NMDA antagonist phencyclidine has known abuse liability but undefined efficacy as an antidepressant. To further evaluate the relationship between antidepressant-like and abuse-related effects of NMDA antagonists, this study evaluated the effects of phencyclidine (1.0-10.0 mg/kg) in male Sprague-Dawley rats responding under two procedures that have been used to assess antidepressant-like effects (differential-reinforcement-of-low-rate [DRL] 72 s schedule of food reinforcement; n = 9) and abuse-related drug effects (intracranial self-stimulation [ICSS]; n = 6). Under the DRL 72 s schedule, phencyclidine (10.0 mg/kg) increased reinforcers and decreased responses without shifting the peak location of the interresponse time (IRT) distribution. Ketamine (10.0 mg/kg) also increased reinforcers and decreased responses, but unlike phencyclidine, it produced a rightward shift in the peak location of the IRT distribution. The 10.0 mg/kg phencyclidine dose that decreased DRL 72 s responding also decreased rates of ICSS for 50 min after its administration; however, abuse-related ICSS facilitation was observed at later times (100-300 min) or after a lower phencyclidine dose (3.2 mg/kg). These results suggest that phencyclidine produces weaker antidepressant-like effects, but stronger abuse-related effects than ketamine in these procedures.

Polysubstance use: diagnostic challenges, patterns of use and health

PURPOSE OF REVIEW

Polysubstance use is common, particularly amongst some age groups and subcultures. It is also associated with elevated risk of psychiatric and physical health problems. We review the recent research findings, comment on changes to polysubstance diagnoses, report on contemporary clinical and epidemiological polysubstance trends, and examine the efficacy of preventive and treatment approaches.

RECENT FINDINGS

Approaches to describing polysubstance use profiles are becoming more sophisticated. Models over the last 18 months that employ latent class analysis typically report a no use or limited-range cluster (alcohol, tobacco and marijuana), a moderate-range cluster (limited range and amphetamine derivatives), and an extended-range cluster (moderate range, and nonmedical use of prescription drugs and other illicit drugs). Prevalence rates vary as a function of the population surveyed. Wide-ranging polysubstance users carry higher risk of comorbid psychopathology, health problems, and deficits in cognitive functioning.

SUMMARY

Wide-ranging polysubstance use is more prevalent in subcultures such as 'ravers' (dance club attendees) and those already dependent on substances. Health risks are elevated in these groups. Research into the prevention and treatment of polysubstance use is underdeveloped. There may be benefit in targeting specific polysubstance use and risk profiles in prevention and clinical research.

Drugs currently in Phase II clinical trials for cocaine addiction

INTRODUCTION

There are no FDA-approved pharmacotherapies for treating cocaine addiction; thus, developing drugs to treat cocaine dependence is an unmet critical need. Fortunately, there are a number of drugs that are currently in Phase II clinical trial/s. This is due in part to the advances from in vivo imaging in humans which provided a roadmap of the neurochemistry of the cocaine-dependent brain. Most drugs currently in Phase II clinical trials attempt to modulate the disturbed neurochemistry in cocaine dependents to resemble those of healthy individuals. These predominantly modulate dopamine, serotonin, glutamate, GABA or noradrenaline signalling.

AREAS COVERED

This review summarizes the therapeutic potential of each drug as evidenced by clinical and preclinical studies. It also discusses their utility in terms of bioavailability and half-life.

EXPERT OPINION

Amphetamine salts and topiramate clearly stand out in terms of their potential efficacy in treating cocaine addiction. The efficacy of topiramate was closely associated with regular cognitive-behavioural therapy (CBT), which highlights the importance of a combined effort to promote abstinence and enhance retention via CBT. Cognitive/psychological screening appears necessary for a more symptom-based approach with more reasonable outcomes other than abstinence (e.g., improved quality of life) in treating cocaine addiction.

A drug use survey among clients of harm reduction sites across British Columbia, Canada, 2012

Background

In British Columbia (BC), understanding of high-risk drug use trends is largely based on survey and cohort study data from two major cities, which may not be representative of persons who use drugs in other regions. Harm reduction stakeholders, representing each of the five geographic health regions in BC, identified a need for data on drug use to inform local and regional harm reduction activities across the province. The aims of this project were to (1) develop a drug use survey that could be feasibly administered at harm reduction (HR) sites across all health regions and (2) assess the data for differences in reported drug use frequencies by region.

Methods

A pilot survey focusing on current drug use was developed with stakeholders and administered among clients at 28 HR supply distribution sites across the province by existing staff and peers. Data were collated and analysed using univariate and bivariate descriptive statistics to assess differences in reported drug use frequencies by geography. A post-survey evaluation was conducted to assess acceptability and feasibility of the survey process for participating sites.

Results

Crack cocaine, heroin, and morphine were the most frequently reported drugs with notable regional differences. Polysubstance use was common among respondents (70%) with one region having 81% polysubstance use. Respondents surveyed in or near their region's major centre were more likely to report having used crack cocaine (p < 0.0001) and heroin (p < 0.0001) in the past week as compared to those residing >50 km from the major centre. Participants accessing services >50 km from the regional centre were more likely to have used morphine (p < 0.0001). There was no difference in powder cocaine use by client/site proximity to the regional centre. Participating sites found the survey process acceptable, feasible to administer annually, and useful for responding to client needs.

Conclusions

The survey was a feasible way for harm reduction sites across BC to obtain drug use data from clients who actively use drugs. Drug use frequencies differed substantially by region and community proximity to the regional centre, underlining the need for locally collected data to inform service planning.

Cannabis use motives and personality risk factors

According to the model of substance abuse of Conrod, Pihl, Stewart, and Dongier (2000), four personality factors (i.e., anxiety sensitivity [AS], introversion/hopelessness [I/H], sensation seeking [SS], and impulsivity [IMP]) are associated with elevated risk for substance use/misuse, with each personality factor being related to preference for particular drugs of abuse (e.g., AS with anxiolytics). However, cannabis use has not been consistently linked to any one of these personality factors. This may be due to the heterogeneity in cannabis use motives. The present study explored the association between these four personality risk factors and different cannabis use motives. Cannabis users completed an interview about their motives for cannabis use as well as the self-report Substance Use Risk Profile Scale (SURPS; Woicik, Conrod, Stewart, & Pihl, 2009), which measures the four personality risk factors. Results showed that AS was associated with conformity motives and I/H was associated with coping motives for cannabis use. SS was positively associated with expansion motives and IMP was associated with drug availability motives. Thus, personality risk factors in the model of Conrod et al. (2000) are associated with distinct cannabis use motives in a pattern consistent with theory.

Use of psychoactive substances by adolescents: current panorama

Adolescence is a period of vulnerability to substance use disorders (SUDs). Epidemiological studies indicate that about 23% of Brazilian adolescents use drugs, with alcohol being the most widely consumed substance. The etiology of SUDs is complex, influenced by an interaction of genetic risk, individual development, environmental factors, context of use, and substance used. Clinicians should consider diagnostic criteria and be aware of behavioral changes that may indicate drug use and its consequences in various aspects of adolescent life. Identification and treatment of comorbid conditions is critical to the management of SUDs in this age group. Interventions should restrict access to drugs and facilitate prompt recognition of initial use, preventing progression to serious patterns of abuse or dependence. Intervention should be broad, including academic and occupational activities as well as social relationships and leisure, which are critical to the reestablishment of normal adolescent development.