Levels and correlates of polydrug use among heroin users and regular amphetamine users

Causes and circumstances of death in stimulant and opioid use-A comparative study

AIMS

To investigate the individual characteristics, causes and circumstances around deaths in stimulant use, and to examine how individuals who died with stimulants in their body differ from individuals who died with opioids in their body.

METHODS

This study includes individuals who died during the years 2000-2018 and underwent a forensic autopsy at Forensic Medicine in Lund, Skåne County, Sweden. All individuals over 18 years of age with stimulants (n = 310), opioids (n = 2,039) or both stimulants and opioids (n = 385) in the body at the time of death, were included. The three groups were assessed regarding gender, age, place of death, BMI, other substances detected in forensic toxicological analysis, organ weights and underlying and contributing causes of death. The data were analysed by frequency and proportion calculations, cross-tabulations and comparisons of medians.

RESULTS

The median age at death of the study population (n = 2,734) was 45.5 years (interquartile range ☯IQR] 32-60 years) and 73.2% were men. The most common cause of death in the stimulant group was suicide (26.8%), higher proportion compared to the opioid group (20.8%) (p = 0.017) and in the polysubstance group accidental poisoning (38.2%), higher proportion compared to the opioid group (18.0%) (p<0.001). Death by transport accidents was significantly associated with the stimulant group (p<0.001) as well as death by other accidents (p = 0.016).

CONCLUSIONS

Individuals who died with stimulants in their body died at a higher rate from suicide, transport accidents and other accidents, compared to individuals who died with opioids in their body. This study indicates the need to identify and prevent psychiatric conditions, elevated suicide risk, and risk-taking behaviors among people who use stimulants.

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

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

Trends and psychosocial correlates of same day polysubstance use among people who inject drugs in Australia, 2012-2022

BACKGROUND

Polysubstance use is associated with negative health and social outcomes among people who inject drugs. We aimed to describe trends in polysubstance use and identify psychosocial correlates and associated drug use risk behaviours. We defined polysubstance use as intentional same day use of more than one of three drug classes: opioids, other non-opioid depressants (hereafter 'depressants'), and stimulants.

METHODS

We used 10 years (2012-2022, excluding 2020) of data from annual surveys in Australian capital cities with people who inject drugs (N=5657) to construct five mutually exclusive polysubstance use profiles: opioid-depressant, opioid-stimulant, stimulant-depressant, opioid-stimulant-depressant, and single drug class use. We examined time trends using the Mann Kendall test and identified correlates using multinomial logistic regression.

RESULTS

Same day polysubstance use was relatively common among this sample (43.6%). Opioid-depressant use was the most frequent polysubstance use profile, but this decreased over the study period (32.6% to 13.3%, p<0.001). This aligned with observed decreases in use of pharmaceutical opioids (p<0.001), opioid agonist treatment (p=0.007), and benzodiazepines (p=0.001). There was no evidence for any trend in the other polysubstance use profiles, although single drug class use increased (51.9% to 64.7%, p=0.031). The different polysubstance use profiles were variously associated with psychosocial factors, including unstable housing and very high psychological distress, and other drug use risk behaviours, including non-fatal overdose, receptive and/or distributive needle sharing, and reusing one's own needles.

CONCLUSION

Same day polysubstance use has remained relatively common among this sample over time, although the typology has changed. Collectively, our findings point to diverse drug use patterns among people who inject drugs and reiterate the need for a range of harm reduction, treatment, and support options.

Addressing injecting related risks among people who inject both opioids and stimulants: Findings from an Australian survey of people who inject drugs

Background

Opioids and stimulants are the most commonly injected illicit drugs worldwide and in Australia. While some people who inject drugs (PWID) prefer either opioids or stimulants, others regularly use both opioids and stimulants. Limited available research indicates that those who use opioids and stimulants together, either in combination or alternating between the two, may engage in injection-related practices which potentially place them at greater health risk and could lead to poorer health outcomes.

Methods

Participants were recruited nationally through member organizations of the Australian Injecting and Illicit Drug Users League (AIVL); these organizations represent PWID in each Australian state and territory. This study compared a sample of PWID (N = 535) who reported past-month injection of opioids only (N = 173), stimulants only (N = 208), or both (N = 154) on a range of health and wellbeing outcomes. PWID completed a survey assessing drugs injected, frequency of injecting, receptive equipment sharing, psychological distress, self-reported hepatitis C (HCV) status, experienced and internalized stigma, drug use salience, and community attachment.

Results

People who injected both opioids and stimulants reported more frequent injecting, more experiences of stigma, and greater reported HCV diagnosis than people who injected stimulants or opioids alone. They also showed greater attachment to a community of PWID and greater salience of drug use to their identity.

Conclusions

The findings of increased injecting and broader harms associated with injecting both stimulants and opioids are important for tailoring harm reduction and intervention designs for people who use both opioid and stimulant drugs, including prioritizing peer-based approaches.

Amphetamine-Type Stimulant Dependence and Association with Concurrent Use of Cocaine, Alcohol, and Cannabis: A Cross-Sectional Study

INTRODUCTION

Amphetamine-type stimulants (ATSs) are the second most commonly used class of illegal substances in Europe. Although concurrent substance use has been subject to research, little is known about associations between concurrent use of cocaine, alcohol, or cannabis and ATS dependence. We expect that the concurrent use of any of the substance, especially cannabis and cocaine, is associated with ATS dependence.

METHODS

Cross-sectional data were gathered within the European ATTUNE study in 2018/2019. Participants (N = 721) were asked about their consumption patterns and social, psychological, and economic situation. Multivariate logistic regressions were carried out for associations between ATS dependence and use combinations of frequent cocaine, alcohol, or cannabis, with the reference group of no frequent concurrent use (model 1). Model 2 calculated associations for ATS dependence with lifetime methamphetamine use for respective use combinations.

RESULTS

The study population was on average 28.9 years old (SD = 7.7), with the majority being male (63.5%). In model 1, the adjusted odds ratio (aOR) for frequent alcohol use was 0.70 (confidence interval [CI] 0.41-1.20). Similar results were shown for model 2 (aOR 0.82, CI 0.42-1.62). Frequent cannabis use significantly reduced the chance for ATS dependence by 50% in adjusted model 1 (aOR 0.50, CI 0.28-0.89) and by 62% in model 2 (aOR 0.38, CI 0.18-0.82). For frequent cocaine use, models 1 and 2 report an aOR at 1.37 (CI 0.58-3.25) and 2.39 (CI 0.77-7.43), although not statistically significant. Frequent users of all 3 substances had a significant 3-fold chance for ATS dependence (model 1: aOR 2.98, CI 1.16-7.63; model 2: aOR 2.95, CI 1.02-8.58).

DISCUSSION

Against initial hypotheses, frequent concurrent use of alcohol or cannabis generally decreased chances for ATS dependence. An explanation could be the study population, which consists of many irregular users of ATS, who mainly consume alcohol or cannabis. Cocaine generally increased chances, although results were not significant. The frequent use of all 3 substances together with ATS in the last year was significantly associated with dependence, thus reporting important information for treatment services. Further research is needed for disentangling causal relationships underlying these associations and for pinpointing consequences for relapse prevention and retention success.

Benzodiazepine misuse and cigarette smoking status in US adults: Results from the National Survey on Drug Use and Health, 2015-2018

BACKGROUND

Benzodiazepines are the third most commonly misused drugs in the U.S.

POPULATION

There is a growing public health concern related to recent increases in benzodiazepine-related overdose deaths, emergency department visits, and treatment admissions. Although benzodiazepine misuse often occurs along with other drug use, little is known about the association between benzodiazepine and cigarette smoking.

METHODS

We used a pooled dataset from the National Survey on Drug Use and Health (NSDUH) for 2015-2018 (N = 171,766). We estimated a multivariable logistic regression model of past-year benzodiazepine misuse as a function of past-year tobacco use (cigarette smoking, other tobacco use), controlling for survey years, sociodemographics, past-year substance use, and psychiatric comorbidities.

RESULTS

Among the analytic sample (N = 171,766), 2.1% (weighted; unweighted n = 4,942) reported they misused benzodiazepines in the past 12 months. In the multivariable logistic regression model, correlates of past-year benzodiazepine misuse were past-year cigarette smoking (aOR = 1.85, 95% CI = 1.67, 2.06) and other tobacco use (e.g., cigars and smokeless tobacco) (aOR = 1.17, 95% CI = 1.03, 1.34), female (aOR = 1.14, 95% CI = 1.04, 1.26), uninsured (aOR = 1.26, 95% CI = 1.12, 1.42), past-year use of alcohol (aOR = 1.48, 95% CI = 1.21, 1.80), cannabis (aOR = 2.76, 95% CI = 2.46, 3.10), and other drugs (aOR = 7.92, 95% CI = 7.08, 8.86), as well as, past-year distress (aOR = 1.84, 95% CI = 1.61, 2.10), and depressive symptoms (aOR = 1.32, 95% CI = 1.16, 1.51).

CONCLUSION

Nicotine is independently associated with benzodiazepine misuse, even after controlling for other drug use and psychiatric variables. Future studies examining potential mechanisms linking nicotine and benzodiazepine use are necessary.

Antidepressants abuse in subjects with opioid use disorders: A 10-year study in the French OPPIDUM program

Accumulating evidence shows that some antidepressants are abused for their psychostimulant effects, but the extent of antidepressants abuse is unknown in subjects with opioid use disorders (OUD). The objective of this work is to assess the prevalence of antidepressant abuse and its correlates in subjects with OUD. Subjects ≥18 year-old in an opiate maintenance treatment (OMT) program who reported using an antidepressant were selected from the OPPIDUM program from 2011 to 2020. The outcome was antidepressant abuse. Antidepressant abusers were identified as subjects reporting at least one of the following behaviors: "drug abuse," "concomitant use of alcohol," "illegal obtaining," and "dose higher than recommended in the Summary of Product Characteristics." Among the 83 040 observations of subjects ≥18 year-old in an OMT program included in the OPPIDUM program from 2011 to 2020, 2708 (3.3%) subjects reported using an antidepressant in monotherapy. Among them, there were 385 (14.2%) abusers. The proportion of abusers was the highest for amitriptyline (n = 31, 25.0%). In multivariate analysis, antidepressant abuse was positively associated with amitriptyline (OR 2.07, 95% CI [1.16, 3.73]; p = 0.015), unemployment (OR 1.52, 95% CI [1.16, 2.01]; p = 0.003), the use of intravenous route of administration (OR 1.77, 95% CI [1.12, 2.80]; p = 0.014), and the use of benzodiazepines (OR 1.53, 95% CI [1.21, 1.94]; p < 0.001). Clinicians should be aware of the risk of antidepressant abuse when prescribing in subjects with OUD, accounting for their heterogeneous pharmacological properties that may account for their abuse potential.

Understanding opioid overdose risk and response preparedness among people who use cocaine and other drugs: Mixed-methods findings from a large, multi-city study

BACKGROUND

Fatal overdoses involving cocaine (powdered or crack) and fentanyl have increased nationally and in Massachusetts. It is unclear how overdose risk and preparedness to respond to an overdose differs by patterns of cocaine and opioid use. Methods: From 2017 to 2019, we conducted a nine-community mixed-methods study of Massachusetts residents who use drugs. Using survey data from 465 participants with past-month cocaine and/or opioid use, we examined global differences (p < 0.05) in overdose risk and response preparedness by patterns of cocaine and opioid use. Qualitative interviews (n = 172) contextualized survey findings. Results: The majority of the sample (66%) used cocaine and opioids in the past month; 18.9% used opioids alone; 9.2% used cocaine and had no opioid use history; and 6.2% used cocaine and had an opioid use history. Relative to those with a current/past history of opioid use, significantly fewer of those with no opioid use history were aware of fentanyl in the drug supply, carried naloxone, and had received naloxone training. Qualitative interviews documented how people who use cocaine and have no history of opioid use are largely unprepared to recognize and respond to an overdose. Conclusions: Public health efforts are needed to increase fentanyl awareness and overdose prevention preparedness among people primarily using cocaine.

Synergistic effects of MDMA and ethanol on behavior: Possible effects of ethanol on dopamine D2 -receptor-related signaling

Polydrug abuse is common among drug abusers. In particular, psychostimulants are often taken with ethanol, and the combination of 3,4-methylenedioxymethamphetamine (MDMA) and alcohol is one of the most common forms of polydrug abuse. However, the mechanism by which these drugs influence behavior remains unclear. The present study was designed to delineate the mechanisms that underlie the effects of the interaction between MDMA and ethanol on behavior in rodents. The combination of MDMA with ethanol enhanced their locomotor-increasing, rewarding, and discriminative stimulus effects without enhancing their effects on the release of dopamine from the nucleus accumbens in rodents. In addition, ethanol potently enhanced locomotor activity produced by the dopamine receptor agonist apomorphine in mice. In antagonism tests, the dopamine D₁ -receptor antagonist SCH23390, but not the D₂ -receptor antagonist haloperidol, completely suppressed hyperlocomotion induced by MDMA. However, hyperlocomotion induced by the co-administration of MDMA and ethanol was potently suppressed by haloperidol. These results suggest that the synergistic effects of MDMA and ethanol are mediated through dopamine transmission, especially through postsynaptical regulation of D₂ -receptor-mediated functions.

Pre-incarceration polysubstance use involving opioids: A unique risk factor of postrelease return to substance use

OBJECTIVE

Justice-involved populations are at increased risk of overdose following release from prison and jail. This risk is exacerbated by polysubstance use, including the use of opioids with other substances. This study explored pre-incarceration polysubstance use involving opioids as a unique risk factor for postrelease return to substance use.

METHODS

The study examined data from a cohort of 501 justice-involved persons who were enrolled in a therapeutic community treatment program while incarcerated. Latent profile validation identified profiles of polysubstance use involving opioids prior to incarceration. Multivariate logistic regression examined return to substance use, defined as self-reported relapse, and a time series model examined time in the community until a relapse event occurred.

RESULTS

A latent profile validation found six unique polysubstance opioid patterns prior to incarceration. Two of these profiles, primarily alcohol and primarily buprenorphine, were at increased and accelerated risk for relapse postrelease relative to a less polysubstance use profile. Both profiles at increased risk had pre-incarceration co-use of marijuana (≈45% of month) and nonmedical use of opioids (≈40% of month) but were unique in their respective near daily use of alcohol and nonmedical buprenorphine.

CONCLUSIONS

Among persons who use opioids returning to the community, return to substance use occurs along a continuum of risk. Providers' consideration of polysubstance use patterns during treatment may assist in mitigating adverse outcomes for patients postrelease.

The phenomics and genetics of addictive and affective comorbidity in opioid use disorder

Opioid use disorder (OUD) creates significant public health and economic burdens worldwide. Therefore, understanding the risk factors that lead to the development of OUD is fundamental to reducing both its prevalence and its impact. Significant sources of OUD risk include co-occurring lifetime and current diagnoses of both psychiatric disorders, primarily mood disorders, and other substance use disorders, and unique and shared genetic factors. Although there appears to be pleiotropy between OUD and both mood and substance use disorders, this aspect of OUD risk is poorly understood. In this review, we describe the prevalence and clinical significance of addictive and affective comorbidities as risk factors for OUD development as a basis for rational opioid prescribing and OUD treatment and to improve efforts to prevent the disorder. We also review the genetic variants that have been associated with OUD and other addictive and affective disorders to highlight targets for future study and risk assessment protocols.

Prevalence and correlates of simultaneous, multiple substance injection (co-injection) among people who inject drugs in Melbourne, Australia

AIMS

To estimate the prevalence of and risk factors associated with concurrent injection of multiple substances (co-injection) among a community-recruited cohort of people who inject drugs.

DESIGN

Cross-sectional study.

SETTING

Melbourne, Australia.

PARTICIPANTS

A sample of 720 actively injecting participants from the Melbourne Injecting Drug User Cohort Study (33% female) was extracted.

MEASUREMENTS

We constructed two statistical models: a logistic regression model analysing correlates of co-injection of any substance combination in the past month and a multinomial logistic regression model analysing correlates of three mutually exclusive groups: heroin-diphenhydramine co-injection only, co-injection of other substances and no co-injection. Risk factors examined included drug use characteristics, demographic characteristics, health service use, hepatitis C status, injection risk behaviours and previous experience of non-fatal overdose.

FINDINGS

One-third [n = 226, 31%; 95% confidence interval (CI): 28-34%] of participants reported co-injecting substances within the past month, with equal numbers of participants reporting injecting combinations of heroin-diphenhydramine (n = 121, 54%; 95% CI = 48-60%) and heroin-methamphetamine (n = 121, 54%; 95% CI = 48-60%). In logistic regression analyses, reporting co-injection of any substance combination was associated with male sex [adjusted odds ratio (aOR) = 1.80, 95% CI = 1.18-2.74, P = 0.006] and injecting daily or more frequently (aOR = 2.04, 95% CI = 1.31-3.18, P = 0.002). In multinomial logistic regression analyses, participants reporting heroin-diphenhydramine co-injection only were significantly more likely to report groin injecting [adjusted relative risk ratio (aRRR) = 6.16, 95% CI = 2.80-13.56, P < 0.001] and overdose (requiring an ambulance) in the past 12 months (aRRR = 2.81, 95% CI = 1.17-6.72, P = 0.021) compared with participants reporting no co-injection or co-injection of other substances.

CONCLUSIONS

A substantial proportion of people who inject drugs report co-injection of multiple substances, which is associated with a range of socio-demographic, drug use and health service use risk factors.

Increasing Heroin-Methamphetamine (Goofball) Use and Related Morbidity Among Seattle Area People Who Inject Drugs

BACKGROUND AND OBJECTIVES

Methamphetamine use is increasing in the United States, potentially including the simultaneous injection of methamphetamine with heroin (goofball). We compared demographic, behavioral, contextual, and health factors among people who inject drugs (PWID) in the Seattle area and who reported that their main drug was goofball, heroin, or methamphetamine.

METHODS

We used data from 2017 and 2019 cross-sectional surveys of clients at Public Health-Seattle & King County's syringe services program (N = 792).

RESULTS

Among PWID participants, 55.3% reported using goofball in the last 3 months, and the proportion reporting goofball as their main drug doubled between 2017 (10.3%) and 2019 (20.1%, P < .001). The goofball group had the highest proportions of people who were aged less than 30, women, homeless or unstably housed, and recently incarcerated. PWID whose main drug was goofball reported considerable health risks and morbidity. Witnessing an opioid overdose was most commonly reported by participants whose main drug was goofball. This group also reported naloxone possession and use in an overdose situation more than other participants. The majority of participants were interested in reducing or stopping their opioid and stimulant use.

DISCUSSION AND CONCLUSIONS

Among PWID, using goofball as a main drug doubled over 2 years and was characterized by contextual and individual factors that increase the risk of morbidity and mortality.

SCIENTIFIC SIGNIFICANCE

This is the first study to characterize goofball use as a main drug. Clinical and public health efforts to diminish morbidity associated with opioid use need to integrate interventions that address the co-use of methamphetamine. (Am J Addict 2020;00:00-00).

Aspiration in lethal drug abuse-a consequence of opioid intoxication

AIMS

The primary objective of this study was to investigate whether the fatalities of opioid abuse are not only related to respiratory depression but also as a result of other side effects such as emesis, delayed gastric emptying, a reduction of the cough reflex, and impaired consciousness leading to the aspiration of gastric contents, a finding regularly observed in drug-related deaths.

DESIGN

A retrospective exploratory study analyzing heroin/morphine/methadone-related deaths submitted to court-ordered autopsy.

SETTING

Center for Forensic Medicine, Medical University of Vienna, Austria (2010-2015).

PARTICIPANTS

Two hundred thirty-four autopsy cases were included in the study: morphine (n = 200), heroin (n = 11), and methadone (n = 23) intoxication.

FINDINGS

Analyses revealed that 41.88% of all deceased showed aspiration of gastric contents with equal gender distribution (p = 0.59). Aspiration was more frequent in younger deceased (χ² = 8.7936; p = 0.012) and in deceased with higher body mass index (BMI) (χ² = 6.2441; p = 0.044). Blood opioid concentration was lower in deceased with signs of aspiration than in non-aspirators (p = 0.013). Toxicological evaluation revealed a high degree of concomitant substance abuse (91%)-benzodiazepines (61.6%) and/or alcohol (21.8%).

CONCLUSIONS

There are lower opioid concentrations in deceased with signs of aspiration, a fact which strongly points to aspiration as alternative cause of death in opioid-related fatalities. Furthermore, this study highlights the common abuse of slow-release oral morphine in Vienna and discusses alternative medications in substitution programs (buprenorphine/naloxone or tamper-resistant slow-release oral morphine preparations), as they might reduce intravenous abuse and opioid-related deaths.

Polysubstance Use Patterns among Justice-Involved Individuals Who Use Opioids

AIM

The current study explores pre-incarceration polysubstance use patterns among a justice-involved population who use opioids. Design: Setting: Data from prison and jail substance use programing in the state of Kentucky from 2015-2017 was examined. Participants: A cohort of 6,569 individuals who reported both pre-incarceration use of opioids and reported the use of more than one substance per day. Measurements: To determine the different typologies of polysubstance use involving opioids, latent profile analysis of the pre-incarceration thirty-day drug use of eight substances was conducted. Multinomial logistic regression predicted latent profile membership. Findings: Six unique profiles of polysubstance use involving opioids and other substances were found; Primarily Alcohol (9.4%), Primarily Heroin (19.0%), Less Polysubstance Use (34.3%), Tranquilizer Polysubstance Use (16.3%), Primarily Buprenorphine (7.8%), and Stimulant-Opioid (13.2%). Profiles differed by rural/urban geography, injection drug use, physical, and mental health symptoms. Conclusion: Findings indicate the heterogeneity of opioid use among a justice-involved population. More diverse polysubstance patterns may serve as a proxy to identifying individuals with competing physical and mental health needs. Future interventions could be tailored to polysubstance patterns during the period of justice-involvement.

Not what the doctor ordered: Motivations for nonmedical prescription drug use among people who use illegal drugs

BACKGROUND

Nonmedical Prescription Drug Use (NMPDU) is common among people who use illegal drugs. NMPDU is particularly problematic among this population however, as medications such as benzodiazepines and gabapentinoids can potentiate the harmful effects of opioids. Despite these harms, there is some evidence that NMPDU can have harm reducing and therapeutic potential for some people who use illegal drugs. This study provides further evidence of the harm reducing motives for NMPDU among people who use illegal drugs in community and prison settings in Wales, UK.

METHODS

In depth, semi-structured interviews were conducted with 60 interviewees recruited from statutory and third sector drug treatment providers operating in five towns and cities in Wales, and from two Welsh prisons. Eligibility was based primarily on whether the person was currently (or previously) a user of illegal drugs and had recent experience of NMPDU.

RESULTS

NMPDU was found to be largely driven by insufficient access to certain prescription medications and treatment. In this context, NMPDU played an important role in alleviating legitimate medical concerns and overcoming logistical and regulatory barriers associated with Opioid Substitution Therapy. NMPDU also had everyday practicality and mitigated many of the everyday harms experienced by people who use drugs, including opioid withdrawal and stimulant comedowns.

CONCLUSION

Results suggest that NMPDU has the potential to mitigate a number of legitimate medical concerns in the absence of treatment. Finding nuanced ways of responding to patient need whilst reducing the potential for NMPDU are therefore needed, and harm reduction strategies that harness the knowledge and expertise of people who use drugs should be encouraged. Additional policy measures that attend to the inequities and social-structural factors that produce and maintain the need to consume prescription medications in ways that are not intended are also required.

One Is Not Enough: Understanding and Modeling Polysubstance Use

Substance use disorder (SUD) is a chronic, relapsing disease with a highly multifaceted pathology that includes (but is not limited to) sensitivity to drug-associated cues, negative affect, and motivation to maintain drug consumption. SUDs are highly prevalent, with 35 million people meeting criteria for SUD. While drug use and addiction are highly studied, most investigations of SUDs examine drug use in isolation, rather than in the more prevalent context of comorbid substance histories. Indeed, 11.3% of individuals diagnosed with a SUD have concurrent alcohol and illicit drug use disorders. Furthermore, having a SUD with one substance increases susceptibility to developing dependence on additional substances. For example, the increased risk of developing heroin dependence is twofold for alcohol misusers, threefold for cannabis users, 15-fold for cocaine users, and 40-fold for prescription misusers. Given the prevalence and risk associated with polysubstance use and current public health crises, examining these disorders through the lens of co-use is essential for translatability and improved treatment efficacy. The escalating economic and social costs and continued rise in drug use has spurred interest in developing preclinical models that effectively model this phenomenon. Here, we review the current state of the field in understanding the behavioral and neural circuitry in the context of co-use with common pairings of alcohol, nicotine, cannabis, and other addictive substances. Moreover, we outline key considerations when developing polysubstance models, including challenges to developing preclinical models to provide insights and improve treatment outcomes.

Social cognition impairments in long-term opiate users in treatment

BACKGROUND

Long-term opiate users experience pervasive social difficulties, but there has been surprisingly limited research focused on social-cognitive functioning in this population.

AIM

The aim of this study was to investigate whether three important aspects of social cognition (facial emotion recognition, theory of mind (ToM) and rapid facial mimicry) differ between long-term opiate users and healthy controls.

METHODS

The participants were 25 long-term opiate users who were enrolled in opiate substitution programmes, and 25 healthy controls. Facial emotion recognition accuracy was indexed by responses to 60 photographs of faces depicting the six basic emotions (happiness, sadness, anger, fear, surprise and disgust). ToM was assessed using the Reading the Mind in the Eyes task, which requires participants to infer mental states of others from partial facial cues. Rapid facial mimicry was assessed by recording activity in the zygomaticus major and corrugator supercilii muscle regions while participants passively viewed images of happy and angry facial expressions.

RESULTS

Relative to the control group, the opiate user group exhibited deficits in both facial emotion recognition and ToM. Moreover, only control participants exhibited typical rapid facial mimicry responses to happy facial expressions.

CONCLUSIONS

These data indicate that long-term opiate users exhibit abnormalities in three distinct areas of social-cognitive processing, pointing to the need for additional work to establish how social-cognitive functioning relates to functional outcomes in this group. Such work may ultimately inform the development of interventions aimed at improving treatment outcomes for long-term opiate users.

Concurrent Alcohol and Opioid Use Among Harm Reduction Clients

BACKGROUND

Harm reduction services infrequently address alcohol use among clients using opioids, despite the evaluated risk of overdose or medical consequences for clients with viral infections. The purpose of this study is to assess concurrent alcohol and opioid use among syringe services and overdose prevention program participants predominately in southern Ohio and northern Kentucky.

METHODS

This is a cross-sectional study using self-report data (n = 1,142) pooled across regional overdose prevention programs and a mobile syringe services program. The outcome variable was concurrent use categorized as no concurrent alcohol, prescription opioid or heroin use; alcohol and heroin or prescription opioid use; and alcohol, prescription opioid and heroin use in the past three months.

RESULTS

The sample was predominantly white (95%), 56% were male and the mean age was 33 years old. Forty-seven percent of the clients had no concurrent use of alcohol and opioids; 20.1% reported concurrent use of alcohol and either heroin or prescription opioids; and 33.4% reported concurrent use of alcohol, heroin and prescription opioids in the past 3 months. Lifetime suicidal ideation and non-opioid drug use were associated with concurrent alcohol and opioid use in the multivariable model.

CONCLUSION

Harm reduction clients with concurrent alcohol and opioid use may warrant enhanced overdose prevention services. Syringe services and overdose prevention program participants may benefit from education or a brief intervention on alcohol consumption.

Does Cannabis Use Influence Opioid Outcomes and Quality of Life Among Buprenorphine Maintained Patients? A Cross-sectional, Comparative Study

OBJECTIVES

Use of various psychoactive substances can influence outcomes of patients on opioid agonist treatment (OAT). While use of alcohol and cocaine has shown to adversely affect OAT results, associated cannabis use shows mixed results. This study aimed to assess the pattern of cannabis use among opioid-dependent patients maintained on buprenorphine. Additionally, the study compared the dose of buprenorphine, opioid-related craving and withdrawals, productivity, and also quality of life between those with and without recent (past 90-day) cannabis use.

METHODS

We collected data on demographic and drug use details in 100 randomly selected adult male patients attending a community drug treatment clinic, who were stabilized on buprenorphine for more than 3 months. Other measures included scores on World Health Organization (WHO)-Alcohol, Smoking and Substance Involvement Screening Tool and WHO-Quality of Life-Brief (WHOQOL-Bref) version.

RESULTS

The average duration of maintenance treatment with buprenorphine was 96 months, with excellent compliance for buprenorphine (86.92 ± 9.58 days in 90 days). Thirty-five per cent had used cannabis in past 90 days, with lifetime use of cannabis in 77%. Participants using cannabis currently were on lower doses of buprenorphine (mean dose per day: 7.9 mg vs 8.9 mg; P = 0.04). Yet, there was no significant difference in the rates of opioid use or opioid withdrawals and craving between the 2 groups. Compliance to OAT, number of days of employment, daily earning, and WHOQOL-Bref scores in all domains were comparable between those with and without cannabis use. Duration of cannabis use, current use of alcohol, and dose of buprenorphine predicted current cannabis use in multivariable logistic regression analysis.

CONCLUSIONS

Cannabis use does not negatively influence opioid outcomes among patients receiving buprenorphine maintenance treatment. There is no difference in productivity and quality of life between individuals maintained on buprenorphine with and without current cannabis use.

Persistence and Subtype Stability of ADHD Among Substance Use Disorder Treatment Seekers

Objective: To examine ADHD symptom persistence and subtype stability among substance use disorder (SUD) treatment seekers. Method: In all, 1,276 adult SUD treatment seekers were assessed for childhood and adult ADHD using Conners' Adult ADHD Diagnostic Interview for Diagnostic and Statistical Manual of Mental Disorders (4th ed.; DSM-IV; CAADID). A total of 290 (22.7%) participants met CAADID criteria for childhood ADHD and comprise the current study sample. Results: Childhood ADHD persisted into adulthood in 72.8% (n = 211) of cases. ADHD persistence was significantly associated with a family history of ADHD, and the presence of conduct disorder and antisocial personality disorder. The combined subtype was the most stable into adulthood (78.6%) and this stability was significantly associated with conduct disorder and past treatment of ADHD. Conclusion: ADHD is highly prevalent and persistent among SUD treatment seekers and is associated with the more severe phenotype that is also less likely to remit. Routine screening and follow-up assessment for ADHD is indicated to enhance treatment management and outcomes.

Is there a discrete negative symptom syndrome in people who use methamphetamine?

BACKGROUND

Positive psychotic symptoms have consistently been associated with methamphetamine use but the presence of a negative symptom cluster remains unclear. We used exploratory factor analysis to examine whether a discrete negative syndrome could be delineated among methamphetamine users, and to examine the clinical correlates of this syndrome.

METHOD

Participants (N = 154) were people who used methamphetamine at least monthly and did not meet DSM-IV diagnostic criteria for lifetime schizophrenia. Scores on the Brief Psychiatric Rating Scale for the past month were subject to exploratory factor analysis. Latent class analysis was applied to resultant factor scores to determine whether negative and positive factors were experienced by the same participants. Past-month substance use measures were days of use for each drug type and methamphetamine dependence assessed using the Severity of Dependence Scale.

RESULTS

We articulated a three-factor model including 'positive/activation symptoms' (e.g. suspiciousness, hallucinations, conceptual disorganisation, tension), 'affective symptoms' (e.g. depression, anxiety) and 'negative symptoms' (e.g. blunted affect, motor retardation). Positive-activation and affective symptoms (but not negative symptoms) were positively correlated with past month days of methamphetamine use (r = 0.16; r = 0.25) and severity of dependence (r = 0.24; r = 0.41). Negative symptoms were correlated with heroin (r = 0.24) and benzodiazepine use (r = 0.21). Latent class analysis revealed a three-class model comprising a positive-symptom class (44%, high positive-activation, low negative symptoms), a negative-symptom class (31%, low positive-activation, high negative symptoms), and a low-symptom class (38%, low on all factors).

CONCLUSIONS

A negative symptom syndrome exists among people who use methamphetamine, but this appears related to polysubstance use rather than forming a part of the psychotic syndrome associated with methamphetamine use. Overlooking the role of polysubstance use on negative symptoms may conflate the profiles of methamphetamine-associated psychosis and schizophrenia.

Health-related quality of life among people who use methamphetamine

INTRODUCTION AND AIMS

We assessed health-related quality of life amongst people who use methamphetamine, examined how this related to different patterns of methamphetamine use and what other factors were associated with decrements in quality of life in this sample.

DESIGN AND METHODS

A cross-sectional survey of 169 at least monthly methamphetamine users. Health utility scores were derived using the Assessment of Quality of Life - 4D for the past month (0 reflects death and 1 represents full health; the population mean Assessment of Quality of Life score in Australia is 0.81). Dependence on methamphetamine was a score of 4+ on the Severity of Dependence Scale. Other measures included days of methamphetamine use and other substance use in the past month, injecting methamphetamine, demographics, psychiatric symptoms (score of 4+ on the Brief Psychiatric Rating Scale items) and a lifetime DSM-IV diagnosis of schizophrenia.

RESULTS

The mean utility score was 0.52 (95% confidence interval 0.48-0.56). Methamphetamine dependence was associated with lower utility (-0.10, P = 0.003) after adjustment for other univariate correlates of utility. Other factors independently associated with lower utility were being a woman (-0.14, P < 0.001), depression (-0.10, P = 0.008), self-neglect (-0.08, P = 0.035), schizophrenia (-0.17, P = 0.003) and fewer years of schooling (0.02 per year, P = 0.037).

DISCUSSION AND CONCLUSIONS

We found poor quality of life in this sample of methamphetamine users relative to the general population, this being associated with both dependence on methamphetamine and other factors, particularly poor mental health. We also found poorer health amongst women.

Polydrug use patterns and their impact on relapse among heroin-dependent patients in Shanghai, China

AIMS

To describe the polysubstance use patterns of heroin-dependent patients and to understand the impact of polysubstance use patterns on relapse during the 5 years after completing compulsory rehabilitation programmes.

DESIGN

In this secondary analysis, the baseline data of 503 heroin-dependent patients were linked with their 5-year follow-up data from official records.

SETTING

Four compulsory rehabilitation centres in Shanghai, China.

PARTICIPANTS

A total of 564 heroin-dependent patients who were discharged from Shanghai compulsory rehabilitation facilities in 2007 and 2008 were recruited. Among these, 503 patients with available follow-up records were included in this analysis.

MEASUREMENTS

The baseline measurements included the Addiction Severity Index, the Temperament and Character Inventory and the Medical Outcomes Study Social Support Scale. Relapses after discharge from the compulsory rehabilitation centres were extracted monthly from the official electronic record system. Latent class analysis was used to identify different polysubstance use patterns. Associations between the identified latent classes and heroin use and the factors related to relapse during the 5-year follow-up were analysed with the Cox regression model.

FINDINGS

Three latent classes were identified in this cohort: (1) alcohol polydrug users (APU; 13.7%), (2) low polydrug users (LPU; 76.5%) and (3) amphetamine-type stimulant polydrug users (ASPU; 9.7%). During the 5-year follow-up, 298 heroin patients relapsed, and the three groups showed different relapse rates (ASPU 69.4 versus LPU 60.5 versus APU 44.9%, P = 0.02). The average durations of abstinence for the three groups differed (ASPU 31.27 ± 3.41 months versus LPU 36.77 ± 1.19 months versus APU 42.46 ± 2.81 months, P = 0.02). Multivariate Cox regression analyses found that the LPU [hazard ratio (HR) = 1.63, 1.06-2.51] and ASPU (HR = 2.10, 1.24-3.56) classes were positively associated with the risk of heroin relapse.

CONCLUSION

Polydrug use patterns differ among heroin-dependent patients in compulsory rehabilitation programmes in China. A history of polydrug use may predict heroin relapse risk among patients in those compulsory rehabilitation programmes.

Change in alcohol and other drug use during five years of continuous opioid substitution treatment

BACKGROUND

English national prospective, observational cohort study of patients continuously enrolled for five years in opioid substitution treatment (OST) with oral methadone and sublingual buprenorphine. This is a secondary outcome analysis of change in use of alcohol and other drug use (AOD) following identification of heroin use trajectories during OST.

METHODS

All adults admitted to community OST in 2008/09 and enrolled to 2013/14 (n = 7717). Data from 11 sequential, six-monthly clinical reviews were used to identify heroin and AOD use trajectories by multi-level Latent Class Growth Analysis. OST outcome in the sixth and seventh year was 'successful completion and no re-presentation' (SCNR) to structured treatment and was assessed using multi-level logistic regression.

RESULTS

With 'rapid decreasing' heroin use trajectory as referent, 'continued high-level' heroin use predicted 'continued high-level' crack cocaine use (relative risk ratio [RRR] 58.7; 95% confidence interval [CI] 34.2-100.5),'continued high-level' alcohol use (RRR 1.2; 95% CI 1.0-1.5), 'increasing' unspecified drug use (RRR 1.7; 95% CI 1.4-2.1) and less 'high and increasing' cannabis use (RRR 0.5; 95% CI 0.4-0.6). 'Increasing' crack use was negatively associated with SCNR outcome for the 'decreasing then increasing' and 'gradual decreasing' heroin use groups (adjusted odds ratio [AOR] 0.5; 95% CI 0.3-0.9 and AOR 0.2; 95% CI 0.1-0.7, respectively).

CONCLUSIONS

Continued high-level heroin use non-response during long-term OST is associated with high-level crack cocaine and alcohol use, increasing unspecified drug use, but less high and increasing cannabis use. Increasing use of crack cocaine is negatively associated with the likelihood that long-term OST is completed successfully.

Patterns and sociodemographic characteristics of substance abuse in Al Qassim, Saudi Arabia: a retrospective study at a psychiatric rehabilitation center

BACKGROUND

The problem of substance abuse is one of the top 20 risk factors for poor health worldwide. Though widely prevalent in the Middle East, there are few studies in Saudi Arabia.

OBJECTIVE

Record the pattern of substances abuse and the sociodemographic characteristics of abusers attending the local rehabilitation center.

DESIGN

Descriptive, retrospective medical record review.

SETTING

Patients admitted to psychiatric rehabilitation center.

METHODS

The sample included all patients admitted to a rehabilitation center during the period of January 2016-December 2016. Data was collected retrospectively from patient records.

MAIN OUTCOME MEASURES

Descriptive epidemiological data and statistical comparisons.

SAMPLE SIZE

612 patients.

RESULTS

The majority of patients (73%) were 21-40 years of age. Polysubstance abuse (60%) and amphetamine (24%) abuse were most predominant in the 20-40 year olds (45%) and high school dropouts (41%). The average number of drugs being used by polysubstance abusers was 2.5 (and the maximum was 6). There was no relationship of family history of drug abuse and mental illness.

CONCLUSION

There was an increased use of polysubstances and amphetamine with a decreased abuse of prescription drugs when compared to previous studies reported in Saudi Arabia. There was a decreasing prevalence for heroin and alcohol. Substance abusers have certain epidemiological, social and drug patterns and we recommend that authorities and planners integrate their efforts to look for the reasons for substance abuse.

LIMITATIONS

Females not included and prevalence of tobacco smoking not studied.

CONFLICT OF INTEREST

None.

The relationship between illicit amphetamine use and psychiatric symptom profiles in schizophrenia and affective psychoses

This study examines whether illicit amphetamine use is associated with differences in the prevalence of specific psychiatric symptoms in a community sample of individuals diagnosed with schizophrenia or affective psychotic disorders. Data was drawn from the Australian Survey of High Impact Psychosis. The Diagnostic Interview for Psychosis was used to measure substance use and psychiatric symptoms. Participants had used amphetamine within their lifetime and had an ICD-10 diagnosis of schizophrenia (n = 347) or an affective psychotic disorder (n = 289). The past year prevalence of psychiatric symptoms was compared among those who had used amphetamine in the past year (past-year use, 32%) with those who had not (former use, 68%). Univariate logistic regression analysis indicated that past-year users with schizophrenia had a significantly higher past year prevalence of hallucinations, persecutory delusions, racing thoughts, dysphoria, and anhedonia relative to former amphetamine users with schizophrenia. There were no significant differences in symptoms between past-year and former users with affective psychotic disorders. The relationship between amphetamine use and specific psychiatric symptoms varies across different psychotic disorders. Amphetamine use may hinder prognosis by exacerbating symptoms of schizophrenia through dopaminergic dysfunctions or depressive vulnerabilities, however, this needs to be confirmed by prospective longitudinal research.

Mortality and causes of death among people who inject amphetamine: A long-term follow-up cohort study from a needle exchange program in Sweden

BACKGROUND

Abuse of amphetamines is a worldwide problem with around 34 million users, and amphetamine is commonly used by people who inject drugs (PWID). Despite this, there is relatively little research on mortality and cause of death among people who use amphetamines primarily. The present study aimed to examine mortality and causes of death among people who inject amphetamine, and compare these results to the general population.

METHODS

This retrospective cohort study was based on data from The Malmö Needle Exchange Program in Sweden (MNEP) and on data from The Swedish National Cause of Death Register. Participants in the MNEP, between 1987 and 2011, with registered national identity number and amphetamine as their primary drug of injection use, were included in the study. Standardized mortality ratios (SMR) was calculated for overall mortality and categories of causes of death.

RESULTS

2019 individuals were included (mean follow-up-time 13.7 years [range 0.02-24.2 years], a total of 27,698 person-years). Of the 448 deceased, 428 had a registered cause of death. The most common causes of death were external causes (n = 162, 38%), followed by diseases of the circulatory system (n = 67, 16%). SMR were significantly elevated (8.3, 95% CI [7.5-9.1]) for the entire study population, and for every category of causes of death respectively.

CONCLUSIONS

People injecting amphetamine as a primary drug were found to have significantly elevated mortality compared with the general population, with high rates of both external and somatic causes of death.

Clinical characteristics of poly-drug abuse among heroin dependents and association with other psychopathology in compulsory isolation treatment settings in China

OBJECTIVE

To investigate clinical characteristics and associations of polydrug abuse among heroin-dependent patients in compulsory isolation settings in China.

METHODS

Structured interviews were conducted in 882 heroin-dependent patients in two compulsory isolation settings in Changsha, China. Descriptive statistics were employed to report prevalence and general information of polydrug abuse among the participants. Bivariate associations were examined between polydrug abuse and variables regarding demographics, heroin use profile and psychopathology. Multivariate logistic regressions were conducted to determine independent factors associated with polydrug abuse.

RESULTS

Of all the participants, 40.6% reported abuse of/dependence on at least one other type of drug/alcohol than heroin/opioids during the month preceding admission, with benzodiazepines and alcohol being the most common type of drugs abused apart from heroin. Antisocial and depressive personality disorders, as well as more severe heroin use patterns, including younger age at initiate use and larger amount used per day, were found to be independently associated with polydrug abuse.

CONCLUSIONS

The prevalence of polydrug abuse and its associated severe heroin use patterns and personality disorders suggests an urgent need of promoting treatment policies and strategies for heroin patients in China to address these issues.

Oxycodone-induced tolerance to respiratory depression: reversal by ethanol, pregabalin and protein kinase C inhibition

BACKGROUND AND PURPOSE

Oxycodone, a prescription opioid, is a major drug of abuse, especially in the USA, and contributes significantly to opioid overdose deaths each year. Overdose deaths result primarily from respiratory depression. We have studied respiratory depression by oxycodone and have characterized how tolerance develops on prolonged exposure to the drug. We have investigated the role of PKC in maintaining tolerance and have examined whether ethanol or pregabalin reverses oxycodone-induced tolerance.

EXPERIMENTAL APPROACH

Respiration was measured in male CD-1 mice by whole-body plethysmography. Mice were preinjected with oxycodone then implanted with mini-pumps (s.c.) delivering 20, 45 or 120 mg·kg-1 ·day-1 oxycodone for 6 days and subsequently challenged with oxycodone (3 mg·kg-1 , i.p.) or morphine (10 mg·kg-1 , i.p.) to assess the level of tolerance.

KEY RESULTS

Oxycodone-treated mice developed tolerance to oxycodone and cross tolerance to morphine-induced respiratory depression. Tolerance was less with 20 mg·kg-1 ·day-1 than with 45 or 120 mg·kg-1 ·day-1 oxycodone treatment. At doses that do not depress respiration, ethanol (0.3 g·kg-1 ), pregabalin (20 mg·kg-1 ) and calphostin C (45 μg·kg-1 ) all reversed oxycodone-induced tolerance resulting in significant respiratory depression. Reversal of tolerance was less in mice treated with oxycodone (120 mg·kg-1 ·day-1 ). In mice receiving ethanol and calphostin C or ethanol and pregabalin, there was no greater reversal of tolerance than seen with either drug alone.

CONCLUSION AND IMPLICATIONS

These data suggest that oxycodone-induced tolerance is mediated by PKC and that reversal of tolerance by ethanol or pregabalin may be a contributory factor in oxycodone overdose deaths.

Sleep disturbance as a predictor of time to drug and alcohol use treatment in primary care

BACKGROUND

Sleep Disturbances (SDs) are a symptom common to mental health disorders (MHD) and substance use disorders (SUD). We aimed to identify the value of SD as a predictor for subsequent treatment of illicit drug and alcohol use disorders (SUDs) in primary care and relative to the predictive value of mental health disorders (MHDs).

METHODS

We used electronic health records data from ambulatory primary care in a safety net Boston area healthcare system from 2013 to 2015 (n = 83,920). SUD (separated into illicit drug use disorder and alcohol use disorder) and MHD were identified through ICD-9 codes and medical record documentation. We estimated Cox proportional hazard models to examine the risk of SUD across four comparison groups (SD only, SD and MHD, MHD only, and neither SD nor MHD).

RESULTS

Compared to patients with no sleep or MHD, patients with SD had a greater risk for subsequent SUD treatment. Approximately one-fifth of patients with SD were treated for an illicit drug use disorder and approximately 12% were treated for alcohol use disorder. Risk for SUD treatment, estimated at over 30% by the end of the study, was greatest for patients with a MHD, either alone or comorbid with SD. Risk was greater for older patients and men, and lower for minority patients.

CONCLUSIONS

SD and MHD, individually and comorbid, significantly predict subsequent treatment of illicit drug and alcohol use disorder in primary care. Screening and evaluation for SD should be a routine practice in primary care to help with identifying potential SUD risk.

Polydrug use and its association with drug treatment outcomes among primary heroin, methamphetamine, and cocaine users

BACKGROUND

Polydrug use may challenge effective treatment for substance use disorders. We evaluate whether secondary substance use modifies the association between treatment and primary drug use among primary heroin, cocaine and methamphetamine (MA) users.

METHODS

Data were obtained from prospective cohort studies on people who use illicit drugs (PWUD) in California, USA. Using repeated monthly data on self-reported secondary substance use (heroin, cocaine, MA, alcohol or marijuana; ≥1day in a month), primary drug use (≥1day in a month), and treatment participation, collected via timeline follow-back, we fitted generalized linear mixed multiple regression models controlling for potential confounders to examine the interactions between treatment and secondary substance use on the odds of primary heroin, cocaine and MA use, respectively.

RESULTS

Included in our study were 587 primary heroin, 444 primary MA, and 501 primary cocaine users, with a median of 32.4, 13.3 and 18.9 years of follow-up, respectively. In the absence of secondary substance use, treatment was strongly associated with decreased odds of primary drug use (adjusted odds ratios (aORs): 0.25, 95% CI: 0.24, 0.27, 0.07 (0.06, 0.08), and 0.07 (0.07, 0.09)) for primary heroin, MA, and cocaine users, respectively. Secondary substance use of any kind moderated these associations (0.82 (0.78, 0.87), 0.25 (0.21, 0.30) and 0.53 (0.45, 0.61), respectively), and these findings were consistent for each type of secondary substance considered. Moreover, we observed different associations in terms of direction and magnitude between secondary substance use and primary drug use during off-treatment periods across substance types.

CONCLUSION

This study demonstrates secondary substance use moderates the temporal associations between treatment and primary drug use among primary heroin, MA and cocaine users. Disparate patterns of polydrug use require careful measurement and analysis to inform targeted treatment for polydrug users.

Prevalence and Correlates of Heroin-Methamphetamine Co-Injection Among Persons Who Inject Drugs in San Diego, California, and Tijuana, Baja California, Mexico

OBJECTIVE

Although persons who inject drugs (PWID) in the western United States-Mexico border region are known to inject both heroin and methamphetamine, little is known about the prevalence and risks associated with co-injection of this depressant-stimulant combination (also known as "goofball" and "Mexican speedball").

METHOD

Baseline data from parallel cohort studies of PWID conducted concurrently in San Diego, CA, and Tijuana, Mexico, were used to estimate the prevalence and identify correlates of heroin-methamphetamine co-injection. PWID older than 18 years of age who reported injecting illicit drugs in the past month (N = 1,311; 32.7% female) were recruited in San Diego (n = 576) and Tijuana (n = 735) and completed interviewer-administered questionnaires. Bivariate and multivariable logistic regression analyses were used to identify correlates of heroin-meth-amphetamine co-injection.

RESULTS

The prevalence of co-injection in the past 6 months was 39.9% overall and was higher in Tijuana (55.8%) than in San Diego (19.8%). In multivariable analyses adjusting for study cohort, distributive syringe sharing, purchasing syringes prefilled with drugs, finding it hard to get new syringes, reporting great or urgent need for treatment, and younger age were independently associated with co-injection. Past-6-month overdose was significantly associated with higher odds of co-injection in San Diego than in Tijuana.

CONCLUSIONS

These findings indicate that heroin-methamphetamine co-injection is more common in Tijuana than in San Diego, yet this practice was only associated with overdose in San Diego. Heroin-methamphetamine coinjection was also independently associated with HIV-associated injection risk behaviors. Overdose-prevention interventions should address co-injection of depressants and stimulants.

Polysubstance use in treatment seekers who inject amphetamine: Drug use profiles, injecting practices and quality of life

BACKGROUND

The injection of amphetamine is becoming increasingly common. However, there has been a lack of research examining people who inject amphetamine as the primary drug of use, limiting the potential to ensure services address the unique needs of this group. The current study used latent class analysis to identify classes of polydrug use among people who report injecting amphetamine during the past 12months. It also examined differences between classes and drug use patterns, injecting practices, quality of life and psychological distress.

METHODS

Participants who were attending non-government specialist alcohol and other drug treatment across New South Wales, Australia and had identified amphetamine as their principle drug of concern and reported injecting amphetamine in the previous 12months were included in the current study (N=827). Latent class analysis was performed to identify polydrug profiles of participants.

RESULTS

The large majority of people in the current study (85%) demonstrated low probability of heroin or other opiate use. Three distinct classes of polydrug use were identified: (1) Low-polydrug (n=491), (2) Opiates-polydrug (n=123), and (3) Alcohol-polydrug (n=213). There was a trend for the Low-polydrug class to demonstrate better functioning and safer injecting practices than the Opiates-polydrug and Alcohol-polydrug classes.

CONCLUSION

The results suggest that the majority of people accessing treatment who inject amphetamine as their primary drug of choice have a low probability of heroin or other opiate use. It is important that future research consider whether traditional harm minimisation strategies are appropriate for people who primarily inject amphetamine.

Effectiveness of treatment for opioid use disorder: A national, five-year, prospective, observational study in England

BACKGROUND

This the first 5-year effectiveness study of publicly funded treatment for opioid use disorder (OUD) in England.

METHODS

All adults initiating treatment in 2008/09 in all 149 local treatment systems reporting to the National Drug Treatment Monitoring System (n=54,347). Admission polydrug use sub-populations were identified by Latent Class Analysis. The treatment outcome measure was 'successful completion and no re-presentation within six months' (SCNR) analysed by multilevel, multivariable logistic regression and funnel plots to contrast outcome by treatment system.

RESULTS

SCNR was achieved by 21.9%. Heroin and crack cocaine users were significantly less likely to achieve this outcome than patients who used heroin only (adjusted odds ratio [AOR] 0.90; 95% confidence interval [CI] 0.85-0.95). Older patients (AOR 1.09; CI 1.07-1.11), those employed (AOR 1.27; CI 1.18-1.37) and those enrolled for longer treatment were more likely to achieve the outcome measure. After risk adjustment, the local treatment systems that achieved substantially better outcome performance (14/149) had a lower rate of opiate prevalence in the local population at time of study initiation (incidence rate difference [IRD] 4.1; CI 4.0-4.2), fewer criminal offences per thousand (IRD 28.5; CI 28.1-28.8) and lower drug-related deaths per million (IRD 5.9; CI 5.9-5.9).

CONCLUSIONS

In an English national study, one fifth of patients successful completed treatment for OUD and did not present for further treatment within six months. Longer time in treatment increases the probability of achieving and maintaining clinical benefit from treatment. After risk-adjustment, an important minority of treatment systems achieve substantially better outcome performance.

Health service utilisation attributable to methamphetamine use in Australia: Patterns, predictors and national impact

AIM AND BACKGROUND

We estimated health service utilisation attributable to methamphetamine use, its national impact and examined other predictors of health service utilisation among dependent methamphetamine users.

METHOD

Past year rates of health service utilisation (number of attendances for general hospitals, psychiatric hospitals, emergency departments, general practitioners, psychiatrists, counsellors or psychologists, and dentists) were estimated for three levels of methamphetamine use (no use, < weekly, ≥ weekly) using panel data from a longitudinal cohort of 484 dependent methamphetamine users from Sydney and Brisbane, Australia. Marginal rates for methamphetamine use were multiplied by 2013 prevalence estimates from the National Drug Strategy Household Survey. Covariates included other substance use, demographics, mental disorders and drug treatment.

FINDINGS

Health service use was high. More frequent methamphetamine use was associated with more frequent presentations to emergency departments (incidence rate ratios 1.3-2.1) and psychiatric hospitals (incidence rate ratios 5.3-8.3) and fewer presentations to general practitioners, dentists and counsellors. We estimate methamphetamine use accounted for between 28 400 and 80 900 additional psychiatric hospital admissions and 29 700 and 151 800 additional emergency department presentations in 2013. More frequent presentations to these services were also associated with alcohol and opioid use, comorbid mental health disorders, unemployment, unstable housing, attending drug treatment, low income and lower education.

CONCLUSIONS

Frequent methamphetamine use has a significant impact on emergency medical and psychiatric services. Better provision of non-acute health care services to address the multiple health and social needs of dependent methamphetamine users may reduce the burden on these acute care services. [McKetin R, Degenhardt L, Shanahan M, Baker AL, Lee NK, Lubman DI. Health service utilisation attributable to methamphetamine use in Australia: patterns, predictors and national impact. Drug Alcohol Rev 2017;00:000-000].

Acting with the future in mind is impaired in long-term opiate users

RATIONALE

Episodic foresight is a fundamental human capacity. It refers to the ability to simulate future situations and organise current actions accordingly. While there is some evidence that opiate users have a reduced capacity to imagine themselves in future situations, no study to date has assessed whether opiate users show deficits in the ability to take steps in the present in anticipation of future needs.

OBJECTIVE

In this study, we assessed whether this functional aspect of episodic foresight is impaired in chronic opiate users and the extent to which any deficits are associated with executive dysfunction.

METHODS AND RESULTS

Participants were 33 long-term opiate users enrolled in an opiate substitution program and 34 controls. Relative to controls, the opiate users displayed significant impairment (medium effect size η ²_p = 0.08) in the two behavioural measures of episodic foresight used (items acquired and items used in the VW Foresight task). Furthermore, executive functioning was associated with foresight ability, although this was restricted to items acquired, and the associations were generally stronger for the control group.

CONCLUSIONS

These data provide important evidence suggesting that the functional aspect of episodic foresight is disrupted in long-term opiate users. While these deficits appear to have some links to impaired executive control, additional work is needed to gain a more complete understanding of the underlying cognitive and neural mechanisms involved. This, in turn, will have important implications for tailoring interventions with opiate users to maximise the likelihood of successful independent functioning.

Prevalence, correlates and patterns of heroin use among young adults in the United States

INTRODUCTION

The prevalence of heroin use, abuse, and dependence has increased considerably over the past decade. This increase has largely been driven by young adults (18-25years). This study aims to improve the understanding of heroin use among young adults by determining the prevalence, correlates, patterns and attitude of heroin use among young adults in the US.

METHODS

The 2011-2013 National Survey on Drug Use and Health was analyzed. Study population included 55,940 young adults with valid interviews. Self-reported lifetime, past-year and past-month use of heroin were examined. Descriptive statistics and adjusted odds ratios were estimated in accordance with the complex survey design.

RESULTS

Of the respondents, 18.4 per 1000 (95% CI=16.8-20.0) used heroin at some time in their lives, and 7.3 per 1000 (95% CI=6.3-8.3) and 3.3 per 1000 (95% CI=2.6-4.0) used heroin in the past year and past month, respectively. The single most common route of heroin use was by sniffing. Majority of young adults reported using heroin in combination with other substances. Users of non-prescribed opioid pain relievers, cigarette smokers, illicit drug users and those arrested and booked for breaking the law, had higher odds of using heroin during their lifetime, in the past-year and past-month.

CONCLUSION

Fewer than 2% reported ever using heroin, and 82% of those reported no use in the past month. Majority were polysubstance users and sniffed heroin in combination with other routes of use. Comprehensive programs that target young adult heroin users and address important risk factors for heroin use are needed.

Abnormal fronto-limbic engagement in incarcerated stimulant users during moral processing

RATIONALE

Stimulant use is a significant and prevalent problem, particularly in criminal populations. Previous studies found that cocaine and methamphetamine use is related to impairment in identifying emotions and empathy. Stimulant users also have abnormal neural structure and function of the ventromedial prefrontal cortex (vmPFC), amygdala, and anterior (ACC) and posterior cingulate (PCC), regions implicated in moral decision-making. However, no research has studied the neural correlates of stimulant use and explicit moral processing in an incarcerated population.

OBJECTIVES

Here, we examine how stimulant use affects sociomoral processing that might contribute to antisocial behavior. We predicted that vmPFC, amygdala, PCC, and ACC would show abnormal neural response during a moral processing task in incarcerated methamphetamine and cocaine users.

METHODS

Incarcerated adult males (N = 211) were scanned with a mobile MRI system while completing a moral decision-making task. Lifetime drug use was assessed. Neural responses during moral processing were compared between users and non-users. The relationship between duration of use and neural function was also examined.

RESULTS

Incarcerated stimulant users showed less amygdala engagement than non-users during moral processing. Duration of stimulant use was negatively associated with activity in ACC and positively associated with vmPFC response during moral processing.

CONCLUSIONS

These results suggest a dynamic pattern of fronto-limbic moral processing related to stimulant use with deficits in both central motive and cognitive integration elements of biological moral processes theory. This increases our understanding of how drug use relates to moral processing in the brain in an ultra-high-risk population.

Predicting Long-term Treatment Utilization among Addicts Entering Detoxification: The Contribution of Help-seeking Models

Detoxification is the entry point into the drug treatment system for many heroin and cocaine addicts. In this paper, we examine both socio-demographic predictors of utilization of long-term treatment and constructs based on theories of help-seeking. Data for this paper were collected from 279 heroin and cocaine dependent individuals, at entry into two detoxification programs and 30 or more days later, to determine their long-term treatment status in the 30 days following detoxification. We find that homeless individuals, those on parole, and those who have used drugs for fewer than 20 years are more likely than their counterparts to be in treatment. Even when an array of sociodemographic characteristics are controlled, constructs drawn from the theory of planned behavior (Ajzen, 1988) –viz. intention to enter treatment, behavioral beliefs favoring treatment, and perceived behavioral control (self-efficacy) contribute significantly to the prediction of treatment utilization.

Substance Abuse, Relapse, and Treatment Program Evaluation in Malaysia: Perspective of Rehab Patients and Staff Using the Mixed Method Approach

This study examined reasons for substance abuse and evaluated the effectiveness of substance treatment programs in Malaysia through interviews with rehab patients and staff. Substance rehab patients (aged 18-69 years; n = 30) and staff (ages 30-72 years; n = 10) participated in semi-structured interviews covering a range of topics, including family and peer relationships, substance use and treatment history, factors for substance use and relapse, motivation for entering treatment, work experience, job satisfaction, treatment evaluation, and patient satisfaction. Most patients did not demonstrate the substance progression trend and had normal family relationships. Most patients reported having peers from normal family backgrounds as well. Various environmental and personal factors was cited as contributing to substance abuse and relapse. There was no significant difference between patient and staff program evaluation scores although the mean score for patients was lower. A holistic treatment approach with a combination of cognitive-behavioral, medical, social, and spiritual components was favored by patients. Suggestions for improving existing programs include better tailoring treatment to individual needs, and providing more post-treatment group support.

A Preliminary Investigation of Individual Differences in Subjective Responses to D-Amphetamine, Alcohol, and Delta-9-Tetrahydrocannabinol Using a Within-Subjects Randomized Trial

Polydrug use is common, and might occur because certain individuals experience positive effects from several different drugs during early stages of use. This study examined individual differences in subjective responses to single oral doses of d-amphetamine, alcohol, and delta-9-tetrahydrocannabinol (THC) in healthy social drinkers. Each of these drugs produces feelings of well-being in at least some individuals, and we hypothesized that subjective responses to these drugs would be positively correlated. We also examined participants’ drug responses in relation to personality traits associated with drug use. In this initial, exploratory study, 24 healthy, light drug users (12 male, 12 female), aged 21–31 years, participated in a fully within-subject, randomized, counterbalanced design with six 5.5-hour sessions in which they received d-amphetamine (20mg), alcohol (0.8 g/kg), or THC (7.5 mg), each paired with a placebo session. Participants rated the drugs’ effects on both global measures (e.g. feeling a drug effect at all) and drug-specific measures. In general, participants’ responses to the three drugs were unrelated. Unexpectedly, “wanting more” alcohol was inversely correlated with “wanting more” THC. Additionally, in women, but not in men, “disliking” alcohol was negatively correlated with “disliking” THC. Positive alcohol and amphetamine responses were related, but only in individuals who experienced a stimulant effect of alcohol. Finally, high trait constraint (or lack of impulsivity) was associated with lower reports of liking alcohol. No personality traits predicted responses across multiple drug types. Generally, these findings do not support the idea that certain individuals experience greater positive effects across multiple drug classes, but instead provide some evidence for a “drug of choice” model, in which individuals respond positively to certain classes of drugs that share similar subjective effects, and dislike other types of drugs.

Opioid substitution and antagonist therapy trials exclude the common addiction patient: a systematic review and analysis of eligibility criteria

BACKGROUND

Eligibility criteria that result in the exclusion of a substantial number of patients from randomized trials jeopardize the generalizability of treatment effect to much of the clinical population. This is important when evaluating opioid substitution and antagonist therapies (OSATs), especially given the challenges associated with treating the opioid-dependent population. We aimed to identify OSAT trials' eligibility criteria, quantify the percentage of the clinical population excluded by these criteria, and determine how OSAT guidelines incorporate evidence from these trials.

METHODS

We performed a systematic review to identify the eligibility criteria used across trials. We searched Medline, EMBASE, PsycINFO, Web of Science, Cochrane Library, Cochrane Clinical Trials Registry (CTR), World Health Organization International CTR Platform Search Portal, and the National Institutes of Health CTR databases from inception to January 1, 2014. To quantify the effect of trials' eligibility criteria on generalizability, we applied these criteria to data from an observational study of opioid-dependent patients (n = 394). We then accessed the Canadian, American, British, and World Health Organization (WHO) OSAT guidelines to evaluate how evidence is used in the recommendations.

RESULTS

Among the 60 trials identified the majority (≥50 % of trials) exclude patients with psychiatric (60 %) and physical comorbidity (51.7 %). Additionally, we found 19 trials exclude patients with current alcohol/substance-use problems (31.7 %), and 29 (48.3 %) exclude patients taking psychotropic medications. These criteria were restrictive and in some cases rendered 70 % of the observational sample ineligible. North American OSAT guidelines made strong recommendations supported by evidence with poor generalizability. National Institute of Health and Care Excellence (NICE) and WHO guidelines for opioid misuse provide a critical assessment of the literature used to inform their recommendations.

CONCLUSIONS

Trials assessing OSATs often exclude patients with concurrent disorders. If the excluded patients respond differently to treatment, results from these trials are likely to overestimate the true effectiveness of OSATs. North American guidelines should consider these limitations when drafting clinical recommendations.

Buprenorphine maintenance program with contracted work/education and low tolerance for non-prescribed drug use: a cohort study of outcome for women and men after seven years

BACKGROUND

A seven-year follow-up of heroin dependent patients treated in a buprenorphine-maintenance program combining contracted work/education and low tolerance for non-prescribed drug use. Gender-specific differences in outcome were analysed.

METHODS

A consecutively admitted cohort of 135 men and 35 women, with eight years of heroin abuse/dependence on average was admitted to enhanced buprenorphine maintenance treatment. Standardized interviews, diagnostic assessments of psychiatric disorders and psychosocial conditions were conducted at admission and at follow-ups. Outcome associated with gender was reported for abstinence, retention, psychiatric symptoms, employment and criminal convictions.

RESULTS

148 patients started treatment. After seven years, 94/148 patients (64%) were retained in the program, employed and abstinent from drugs and alcohol. Women had more continuous abstinence, retention and employment than men (76% versus 60%). After one year patients with a high-risk consumption of alcohol were no longer heavy consumers of alcohol and remained so throughout the study (p < .001). All women regained custody of their children. At admission, more women than men had been admitted for psychiatric disorders (70%/44%) and to compulsory care for substance abuse (30%/18%). Initial gender differences of psychiatric co-morbidity decreased and were no longer significant after one year. More men than women had been imprisoned (62% versus 27%) or in non-institutional care (80% versus 49%). Criminal convictions were reduced from 1751 convictions at admission to 742 (58%) after seven years. Eight patients in the entire cohort died over the 7 years (0.7% per year). One patient died in the completers group while still in the program (0.1% per year).

CONCLUSIONS

After seven years, two thirds of the patients in the program were abstinent and employed. Convictions ceased in the completers group. One patient died in the completers group. Women had superior long-term outcome compared to men: more continuous abstinence, employment and fewer convictions. Women also lived with their children to a higher extent than men. The positive outcome highlights the importance of maintaining high structure in combining pharmacological treatment with a focus on employment and psychological treatment and low tolerance for non-prescribed drug use.

Associations of substance use patterns with attempted suicide among persons who inject drugs: can distinct use patterns play a role?

BACKGROUND

While the elevated risk of suicide attempt among persons who inject drugs (PWID) is well documented, whether use of different substances is associated with varying degrees of risk remains unclear. We sought to examine the associations between substance use patterns and attempted suicide in a prospective cohort of PWID in Montreal, Canada.

METHODS

Between 2004 and 2011, participants completed an interviewer-administered questionnaire eliciting information on socio-demographics, substance use patterns, related behaviors, and mental health markers. Generalized estimating equations were used to model the relationship between self-reported use of six common substances (cocaine, amphetamine, opioids, sedative-hypnotics, cannabis and alcohol), associated patterns of use (chronic, occasional and none), and a recent (past six-month) suicide attempt.

RESULTS

At baseline, of 1240 participants (median age: 39.1, 83.7% male), 71 (5.7%) reported a recent suicide attempt. Among 5621 observations collected during follow-up, 221 attempts were reported by 143 (11.5%) participants. In multivariate analyses adjusting for socio-demographics and psychosocial stressors, among primary drugs of abuse, chronic [adjusted odds ratio (AOR): 1.97] and occasional (AOR: 1.92) cocaine use, and chronic amphetamine use (AOR: 1.96) were independently associated with attempted suicide. Among co-used substances, chronic sedative-hypnotic use was independently associated with an attempt (AOR: 2.29). No statistically significant association was found for the remaining substances.

CONCLUSION

Among PWID at high risk of attempted suicide, stimulant users appear to constitute a particularly vulnerable sub-group. While the mechanisms underlying these associations remain to be elucidated, findings suggest that stimulant-using PWID should constitute a prime focus of suicide prevention efforts.

Updated findings of the association and functional studies of DRD2/ANKK1 variants with addictions

Both nicotine and alcohol addictions are severe public health hazards worldwide. Various twin and family studies have demonstrated that genetic factors contribute to vulnerability to these addictions; however, the susceptibility genes and the variants underlying them remain largely unknown. Of susceptibility genes investigated for addictions, DRD2 has received much attention. Considering new evidence supporting the association of DRD2 and its adjacent gene ankyrin repeat and kinase domain containing 1 (ANKK1) with various addictions, in this paper, we provide an updated view of the involvement of variants in DRD2 and ANKK1 in the etiology of nicotine dependence (ND) and alcohol dependence (AD) based on linkage, association, and molecular studies. This evidence shows that both genes are significantly associated with addictions; however the association with ANKK1 appears to be stronger. Thus, both more replication studies in independent samples and functional studies of some of these variants are warranted.

A randomized study of contingency management and spirometric lung age for motivating smoking cessation among injection drug users

Background

Even after quitting illicit drugs, tobacco abuse remains a major cause of morbidity and mortality in former injection drug users. An important unmet need in this population is to have effective interventions that can be used in the context of community based care. Contingency management, where a patient receives a monetary incentive for healthy behavior choices, and incorporation of individual counseling regarding spirometric “lung age” (the age of an average healthy individual with similar spirometry) have been shown to improve cessation rates in some populations. The efficacy of these interventions on improving smoking cessation rates has not been studied among current and former injection drug users.

Methods

In a randomized, factorial design study, we recruited 100 active smokers from an ongoing cohort study of current and former injection drug users to assess the impact of contingency management and spirometric lung age on smoking cessation. The primary outcome was 6-month biologically-confirmed smoking cessation comparing contingency management, spirometric lung age or both to usual care. Secondary outcomes included differences in self-reported and biologically-confirmed cessation at interim visits, number of visits attended and quit attempts, smoking rates at interim visits, and changes in Fagerstrom score and self-efficacy.

Results

Six-month biologically-confirmed smoking cessations rates were 4% usual care, 0% lung age, 14% contingency management and 0% for combined lung age and contingency management (p = 0.13). There were no differences in secondary endpoints comparing the four interventions or when pooling the lung age groups. Comparing contingency management to non-contingency management, 6-month cessation rates were not different (7% vs. 2%; p = 0.36), but total number of visits with exhaled carbon monoxide-confirmed abstinence were higher for contingency management than non-contingency management participants (0.38 vs. 0.06; p = 0.03), and more contingency management participants showed reduction in their Fagerstrom score from baseline to follow-up (39% vs. 18%; p = 0.03).

Conclusions

While lung age appeared ineffective, contingency management was associated with more short-term abstinence and lowered nicotine addiction. Contingency management may be a useful tool in development of effective tobacco cessation strategies among current and former injection drug users.

Trial registration

Clinicaltrials.gov NCT01334736 (April 12, 2011).

Static and dynamic predictors of criminal involvement among people with heroin dependence: findings from a 3-year longitudinal study

BACKGROUND

The link between heroin use and crime has been well established; however, there has been little opportunity to examine this relationship longitudinally. This study examines the relationship between static and dynamic predictors of criminal involvement, and the degree to which changes in dynamic risk factors moderate the risk of criminal involvement over time.

METHOD

Data were collected as part of the Australian treatment outcome study, a 3-year longitudinal study of 615 people with heroin dependence conducted in Sydney, Australia. Past-month criminal involvement (property crime, drug dealing, fraud, violent crime), demographic, drug use and mental health characteristics were assessed at each interview.

RESULTS

Criminal involvement was consistently and independently predicted by lack of wage/salary as a main source of income, (OR 2.17), meeting diagnostic criteria for anti-social personality disorder (OR 1.91) and major depression (OR 1.41), screening positive for borderline personality disorder (OR 1.47), male sex (OR 1.44), a criminal history (OR 1.33), greater severity of dependence (OR 1.21), more extensive heroin use (OR 1.09), and younger age (OR 0.96) over the 3-year period.

CONCLUSIONS

These findings provide strong evidence of the robust nature of the association between more extensive heroin use, severity of dependence, the co-occurrence of mental health conditions, and an individual's capacity for employment, and criminal involvement. Interventions aimed at increasing an individual's employability and improving mental health in particular, may reduce the risk of criminal involvement among people with heroin dependence.