Not just heroin: Extensive polysubstance use among US high school seniors who currently use heroin

Cognitive impairment as a predictor of long-term psychological distress in patients with polysubstance use disorders: a prospective longitudinal cohort study

BACKGROUND

The association between polysubstance use disorder (pSUD), mental illness, and cognitive impairments is well established and linked to negative outcomes in substance use disorder treatment. However, it remains unclear whether cognitive impairment predicts long-term psychological distress among treatment seeking patients with pSUD. This study aimed to investigate the associations and predictive ability of cognitive impairment on psychological distress one and 5 years after treatment initiation.

METHODS

N = 164 treatment seeking patients with pSUD were sampled at treatment initiation. We examined associations between cognitive impairment according to Montreal Cognitive Assessment® (MoCA®), Wechsler Abbreviated Scale of Intelligence (WASI), and Behaviour Rating Inventory of Executive Function - Adult version (BRIEF-A) administered at treatment initiation and psychological distress defined by the Symptom Check List-90-Revised (SCL-90-R) at treatment initiation, one and five years later. We ran hierarchical logistic regressions to assess the predictive ability of the respective cognitive instruments administered at treatment initiation on psychological distress measured one and five years later including psychological distress at treatment initiation and substance intake at the time-points of the measurements as covariates.

RESULTS

The main results was that MoCA® and BRIEF-A predicted psychological distress at years one and five, but BRIEF-A lost predictive power when accounting for psychological distress at treatment initiation. WASI predicted psychological distress at year one, but not at year five.

CONCLUSIONS

Results from MoCA® and WASI was found to be less sensitive to the effect of psychological distress than BRIEF-A. Cognitive impairment at treatment initiation may hold predictive value on later psychological distress, yet its clinical utility is uncertain.

Perigestational Opioid Exposure Alters Alcohol-Driven Reward Behaviors in Adolescent Rats

Every fifteen minutes, a baby is born in the U.S. experiencing neonatal opioid withdrawal syndrome (NOWS). Since 2004, the rate of NOWS has increased 7-fold. Clinical studies have established intrauterine exposure to drugs of abuse as a risk factor for adverse health outcomes in adult life, including the propensity for future illicit drug use. Despite extensive knowledge about common mechanisms of action in the neural circuitry that drives opioid and alcohol reward, there is little data on the risks that those born with NOWS face regarding alcohol use later in life. Here, we investigate the impact of perigestational opioid exposure (POE) on the mesolimbic reward system of male and female Sprague Dawley rats at postnatal and adolescent ages. Our laboratory has developed a clinically relevant model for morphine exposure spanning pre-conception to the first week of life. Using this model, we found that POE increased alcohol consumption in female rats under noncontingent conditions, and inversely, reduced alcohol consumption in both male and female rats during operant conditioning sessions. Operant responding was also reduced for sucrose, suggesting that the impact of POE on reward-seeking behaviors is not limited to drugs of abuse. Expression of µ-opioid receptors was also significantly altered in the nucleus accumbens and medial habenula, regions previously shown to play a significant role in reward/aversion circuitry.

Significance Statement

Early life exposure to opioids is known to alter future drug behavior in rats. In the present study, female rats exposed to morphine via their mothers throughout and after pregnancy exhibited increased alcohol consumption when allowed to consume freely. During operant conditioning, however, male and female rats exposed to gestational morphine decreased consumption of alcohol as well as sucrose. We also observed that gestational morphine exposure altered µ-opioid receptor expression in reward-related brain regions. Our study provides the first evidence of changes in alcohol-directed reward behavior in a gestational opioid exposure rat model.

Nonpartner Violence Perpetration Among Emerging Adults: Associations With Polysubstance Use and Trait Mindfulness

Objective

Violence is a leading cause of death among individuals ages 18-25, with alcohol misuse consistently linked with violence perpetration. However, the association between polysubstance use and violence perpetration is less clear, despite the frequency of use of alcohol with other drugs. Additionally, protective factors such as mindfulness that may reduce violence perpetration among emerging adults have been understudied. This cross-sectional study examined the association between substance use, trait mindfulness, and violence perpetration outside of romantic relationships, utilizing a compensatory model of resilience.

Methods

Data were drawn from a sample of 665 emerging adults ages 18-25, recruited from an urban Emergency Department (68% men). Participants self-administered a computer survey that assessed non-partner violence perpetration (NPV), alcohol use, marijuana use, prescription drug misuse, and trait mindfulness. Fifteen percent reported non-partner violence perpetration over the past six months.

Results

Multivariate logistic regression tested associations between violence perpetration, substance use, trait mindfulness, and demographic characteristics. Results showed that alcohol use alone (OR= 3.04), prescription opioid use alone (OR = 3.58), alcohol and marijuana use (OR = 3.75), and use of all three substances (OR= 7.78) were positively associated with violence perpetration. Post-hoc contrasts demonstrated the polysubstance use significantly increased risk over single substance use. Trait mindfulness (OR= 0.97) was negatively associated with violence perpetration after controlling for substance use.

Conclusions

Findings suggest that polysubstance use may increase risk for violence. Interventions that address polysubstance use, potentially including mindfulness, could reduce non-partner violence perpetration among emerging adults and requires further study.

Goofballing of Opioid and Methamphetamine: The Science Behind the Deadly Cocktail

Globally, millions of people suffer from various substance use disorders (SUD), including mono-and polydrug use of opioids and methamphetamine. Brain regions such as the cingulate cortex, infralimbic cortex, dorsal striatum, nucleus accumbens, basolateral and central amygdala have been shown to play important roles in addiction-related behavioral changes. Clinical and pre-clinical studies have characterized these brain regions and their corresponding neurochemical changes in numerous phases of drug dependence such as acute drug use, intoxication, craving, withdrawal, and relapse. At present, many studies have reported the individual effects of opioids and methamphetamine. However, little is known about their combined effects. Co-use of these drugs produces effects greater than either drug alone, where one decreases the side effects of the other, and the combination produces a prolonged intoxication period or a more desirable intoxication effect. An increasing number of studies have associated polydrug abuse with poorer treatment outcomes, drug-related deaths, and more severe psychopathologies. To date, the pharmacological treatment efficacy for polydrug abuse is vague, and still at the experimental stage. This present review discusses the human and animal behavioral, neuroanatomical, and neurochemical changes underlying both morphine and methamphetamine dependence separately, as well as its combination. This narrative review also delineates the recent advances in the pharmacotherapy of mono- and poly drug-use of opioids and methamphetamine at clinical and preclinical stages.

Trends in Benzodiazepine Prescribing for US Adolescents and Young Adults From 2008 to 2019

This cohort study examines whether trends exist in the number of benzodiazepines and opioids prescribed to adolescents and young adults between 2008 and 2019.

Role of Acetaldehyde in Ethanol Reversal of Tolerance to Morphine-Induced Respiratory Depression in Mice

Background: Opioid users regularly consume other drugs such as alcohol (ethanol). Acute administration of ethanol rapidly reverses tolerance to morphine-induced respiratory depression. However, recent research has suggested that the primary metabolite of ethanol, acetaldehyde, may play a key role in mediating the CNS effects seen after ethanol consumption. This research investigated the role of acetaldehyde in ethanol reversal of tolerance to morphine-induced respiratory depression.

Methods: Tolerance was induced in mice by 6-days implantation of a 75 mg morphine pellet with control mice implanted with a placebo pellet. Tolerance was assessed by acute morphine administration on day 6 and respiration measured by plethysmography. Levels of acetaldehyde were inhibited or enhanced by pre-treatments with the acetaldehyde chelator D-penicillamine and the inhibitor of acetaldehyde dehydrogenase disulfiram respectively.

Results: Morphine pellet implanted mice displayed tolerance to an acute dose of morphine compared to placebo pellet implanted controls. Acute acetaldehyde administration dose-dependently reversed tolerance to morphine respiratory depression. As previously demonstrated, ethanol reversed morphine tolerance, and this was inhibited by D-penicillamine pre-treatment. An acute, low dose of ethanol that did not significantly reverse morphine tolerance was able to do so following disulfiram pre-treatment.

Conclusion: These data suggest that acetaldehyde, the primary metabolite of ethanol, is responsible for the reversal of morphine tolerance observed following ethanol administration.

The release of abuse-deterrent OxyContin and adolescent heroin use

OBJECTIVE

To determine the association between the abuse-deterrent reformulation of OxyContin and adolescent lifetime heroin use in the United States.

METHODS

The quasi-experimental study uses individual survey data from the 1999-2019 Youth Risk Behavior Surveillance System to examine whether the reformulation of OxyContin in August 2010 affected adolescent lifetime heroin use, exploiting heterogeneity in state-level rates of OxyContin misuse before the reformulation. Multiple regression analysis adjusted for state and year fixed effects, adolescent demographics, and time-varying state characteristics and policies.

RESULTS

The release of the abuse-deterrent reformulation of OxyContin was associated with a reduction in adolescents reporting ever using heroin. An adolescent in a state with a one percentage point higher state-level rate of pre-reformulation OxyContin misuse was 1.7% points less likely to report ever using heroin after the reformulation (95% confidence interval, [(CI) = -0.007, -0.027]). These effects are strongest for adolescent males (estimate: -0.028, [(CI) = -0.016, 0.040]) and non-whites (estimate: -0.021, [(CI) = -0.005, -0.037]).

CONCLUSIONS

These results suggest the release of abuse-deterrent OxyContin is associated with a decrease in the likelihood of adolescent lifetime heroin use in states with higher pre-reformulation rates of OxyContin misuse. Pharmaceutical innovations and policies that reduce the likelihood of prescription opioid misuse may be effective in reducing adolescent lifetime heroin use.

Polysubstance use trends and variability among individuals with opioid use disorder in rural versus urban settings

Rural areas of the United States have been disproportionately impacted by the opioid epidemic, exacerbated by COVID-19-related economic upheavals. While polysubstance use is an important determinant of overdose risk, variability in polysubstance use as a result of numerous factors (e.g., access, preference) has yet to be described, particularly among rural persons with opioid use disorder (PWOUD). Survey data on past-month use of prescription and illicit opioids and 12 non-opioid psychoactive drug classes were analyzed from a national sample of rural (n = 3872) and urban (n = 8153) residents entering treatment for OUD from 2012 to 2019. Trend analyses for opioid and stimulant use were compared between rural and urban PWOUD. Latent class analyses assessed substance use trends through identified typologies of rural/urban PWOUD, which then underwent comparative analyses. By 2019, prescription opioid use remained greater in rural versus urban PWOUD, and methamphetamine use showed greater growth in rural, compared to urban areas. Latent class analyses identified variability in polysubstance use, with five identical subgroups in rural/urban PWOD: high polysubstance, polyprescription, prescription opioid-focused, prescription opioid-focused with polysubstance use, and illicit opioid-focused. Polyprescription was highest in rural areas, with illicit opioid-focused use highest in urban areas. Demographic characteristics, co-morbid conditions and healthcare coverage were all associated with between-group differences. There is significant variability in polysubstance use that may identify specific prevention and treatment needs for subpopulations of OUD patients: interventions focused on reducing opioid prescriptions, early engagement with mental health resources, wider distribution of naloxone, and screening/treatment plans that take into account the use of multiple substances.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

The Effects of Early Onset Tranquilizers, Sedatives, and Sleeping Pills Use on Recent Consumption Among Adolescents

BACKGROUND

Adolescents' consumption of tranquilizers, sedatives, and sleeping pills (TSSp) has increased during the last few decades, and TSSp are currently among the substances with the lowest age-of-onset. We characterized current-use patterns of TSSp consumers by age when first taken.

METHODS

This study used individualized secondary data retrieved from the 2016 Spanish State Survey on Drug Use in Secondary Education (16-18-year-olds), and included all subjects who reported having taken TSSp at any point, but excluded those who had started during the previous year (n = 1502). Logistic regression models were used to obtain adjusted odds ratios (aOR) for associations between early TSSp consumption (<14 years) and current TSSp use patterns, adjusted for sociodemographic factors.

RESULTS

About 17.9% of respondents had taken TSSp (average age-of-onset = 13.7) and 45% of these without a prescription. TSSp consumption at <14 years was higher for males and nonrepeaters. Having begun to use TSSp < 14 years was associated with both higher probability of consumption in the last month (aOR = 1.41; 95%CI:1.12-1.77) and daily/almost daily consumption in the last month (aOR = 1.56; 95CI%:1.16-2.08).

CONCLUSIONS

The results of this study show there is a high proportion of 16 to 18 TSSp student consumers - both prescribed and nonprescribed; it also establishes that early onset-of-use is associated with higher levels of intensive use later on.

Substance consumption and intoxication patterns in a medically supervised overdose prevention program for people experiencing homelessness

Background: Opioid overdose is a leading cause of death among homeless individuals. Combining psychoactive substances with opioids increases overdose risk. This study aimed to describe intoxication patterns at a drop-in space offering medical monitoring and harm reduction services to individuals who arrive intoxicated and at risk of overdose. Methods: We examined data from visits to the Supportive Place for Observation and Treatment at Boston Health Care for the Homeless Program between January 1, 2017 and December 31, 2017. We used k-means cluster analysis to characterize intoxication patterns based on clinically assessed sedation levels and vital sign parameters. Multinomial logistic regression analysis assessed demographic and substance consumption predictors of cluster membership. Linear and logistic regression models examined associations between cluster membership and care outcomes. Results: Across 305 care episodes involving 156 unique patients, cluster analysis revealed 3 distinct intoxication patterns. Cluster A (26.6%) had mild sedation and normal vital signs. Cluster B (44.5%) featured greater sedation with bradycardia and/or hypotension. Cluster C (28.9%) was comparable to cluster B but with the addition of hypoxia. Self-reported consumption of non-opioid sedatives prior to arrival was common (63.3% of episodes) and predicted membership in cluster B (aOR 2.75, 95% CI 1.40, 5.40) and cluster C (aOR 3.38, 95% CI 1.48, 7.70). In comparison to cluster A episodes, cluster C episodes were longer (mean 4.8 vs. 2.3 hours, p < 0.001) and more likely to require supplemental oxygen (27.3% vs. 2.5%, p < 0.001). Few episodes required hospital transfer (4.7%) or naloxone (1.0%). No deaths occurred. Conclusions: In a medically supervised overdose monitoring program, reported use of non-opioid sedatives strongly predicted more complex clinical courses and should be factored into overdose prevention efforts. Low-threshold medical monitoring in an ambulatory setting was sufficient for most episodes, suggesting a role for such programs in reducing harm and averting costly emergency services.

Poly-prescription drug misuse across the life course: Prevalence and correlates across different adult age cohorts in the U.S

BACKGROUND

Most research on prescription drug misuse (PDM) focuses on the misuse of specific classes of psychoactive prescription drugs among adolescents or young adults. The current research addressed important gaps in the literature by assessing poly-prescription drug misuse (poly-PDM), the misuse of more than one class of psychoactive prescription drug, across different adult age cohorts.

METHODS

We used the 2015-2018 National Survey on Drug Use and Health to examine the prevalence of past-year poly-PDM and specific combinations of PDM. Multinomial logistic regression was used to identify demographic, health-related factors, and substance use behaviors that were significantly associated with poly-PDM.

RESULTS

The prevalence of poly-PDM decreases with age and is common among individuals who engage in PDM. Slightly more than one in four respondents in age cohorts 18-25 (31.66%, 95% CI = 30.35, 33.00) and 26-34 (29.92%, 95% CI = 25.82, 30.12) who engage in PDM, misused more than one class of prescription drug. Additionally, poly-PDM was identified as a high-risk type of PDM as roughly 60% of adults younger than 65 who endorse poly-PDM reported having a substance use disorder (SUD). While certain characteristics (i.e., race/ethnicity, marital status, depression, suicidal ideation, illegal drug use, and SUD) were consistently associated with poly-PDM across age cohorts, other characteristics (i.e., sexual identity, income, and justice involvement) varied across age cohorts. Finally, a comparison of poly-PDM to single PDM showed, in all age cohorts, that having an SUD was associated with an increased likelihood of poly-PDM, while Black adults were less likely than whites to report poly-PDM.

CONCLUSIONS

By identifying prevalence and correlates of poly-PDM across adult age cohorts, the current research has significant implications. Understanding stability and heterogeneity in the characteristics associated with poly-PDM should inform interventions, identify at-risk groups, and shape public health approaches to dealing with high-risk substance use behavior.

Cannabis use is associated with reduced risk of exposure to fentanyl among people on opioid agonist therapy during a community-wide overdose crisis

BACKGROUND

The ongoing opioid overdose crisis is driven largely by exposure to illicitly-manufactured fentanyl. Preliminary observational and experimental research suggests that cannabis could potentially play a role in reducing use of prescription opioids among individuals with chronic pain. However, there is limited data on the effects of cannabis on illicit opioid consumption, particularly fentanyl, especially among individuals on opioid agonist therapy (OAT). We sought to assess the longitudinal association between cannabis use and exposure to fentanyl among people on OAT.

METHODS

Data were drawn from two community-recruited prospective cohorts of people who use drugs in Vancouver, Canada. We used generalized linear mixed-effects modeling, adjusted by relevant confounders, to investigate the relationship between cannabis use and recent fentanyl exposure (both assessed by urine drug testing) among participants on OAT between 2016 and 2018.

RESULTS

Among the 819 participants on OAT who contributed 1989 observations over the study period, fentanyl exposure was common. At the baseline interview, fentanyl was detected in a majority of participants (431, 53 %), with lower prevalence among individuals with urine drug tests positive for tetrahydrocannabinol (47 vs. 56 %, p = 0.028). Over all study interviews, cannabis use was independently associated with reduced likelihood of being recently exposed to fentanyl (Adjusted Prevalence Ratio = 0.91, 95 % Confidence Interval: 0.83 - 0.99).

CONCLUSIONS

Participants on OAT using cannabis had significantly lower risk of being exposed to fentanyl. Our findings reinforce the need for experimental trials to investigate the potential benefits and risks of controlled cannabinoid administration for people on OAT.

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

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

Substance use patterns and health profiles among US adults who use opioids, methamphetamine, or both, 2015-2018

BACKGROUND

Methamphetamine use, with and without opioids, has increased substantially, but little is known about the sociodemographic characteristics, substance use patterns, or health profiles of individuals who use methamphetamine. To design effective public health interventions, health care professionals and policymakers need data describing individuals who are using methamphetamine in the midst of the opioid crisis.

METHODS

We used 2015-2018 data from the National Survey on Drug Use and Health and included non-elderly adults aged 18-64 years. We categorized respondents into three groups: use of opioids without methamphetamine use, use of methamphetamine without opioid use, or use of both opioids and methamphetamine. Multiple logistic regression models controlling for sociodemographic factors were used to compare substance use characteristics and measures of individual health between the three groups.

RESULTS

People who used any methamphetamine were more likely to be unstably housed, low-income, and live in rural areas. Use of both opioids and methamphetamine was associated with a 132 % higher prevalence of injection needle use, and a nearly twofold higher prevalence of viral hepatitis compared with opioid use alone. One third of individuals reporting use of both opioids and methamphetamine had a severe mental illness, a 55 % higher prevalence than those using opioids alone.

CONCLUSIONS

Individuals who used opioids and methamphetamine had more complex substance use and health profiles than individuals who used opioids alone. These findings suggest public health and harm reduction approaches designed to address opioid use remain important in an era of rising methamphetamine use.

DARK Classics in Chemical Neuroscience: Heroin and Desomorphine

Opioids are arguably one of the most important pharmacologic classes, mainly due to their rich history, their useful and potent analgesic effects, and also, just as importantly, their "Dark Side", constituted by their reinforcing properties that have led countless of users to a spiral of addiction, biological dependence, tolerance, withdrawal syndromes, and death. Among the most significant abused and addictive known opioids are heroin and desomorphine, both synthetic derivatives of morphine that belong to the 4,5-epoxymorphinan structural chemical group of the opioid family drugs. These agents share not only structural, pharmacological, and epidemiological features but also a common geographical distribution. A drop in Afghan heroin production and its "exports" to Russia gave rise to widespread consumption of desomorphine in ex-Soviet republics during the first decade of the 21st century, representing an economical and accessible alternative for misusers to this sort of derivative. Herein we review the state of the art of history, chemistry and synthesis, pharmacology, and impact on society of these "cursed cousins".

Prescription opioid misuse among adolescents and emerging adults in the United States: A scoping review

The U.S. opioid epidemic is a critical public health problem. As substance use and misuse typically begin in adolescence and emerging adulthood, there is a critical need for prevention efforts for this key developmental period to disrupt opioid misuse trajectories, reducing morbidity and mortality [e.g., overdose, development of opioid use disorders (OUD)]. This article describes the current state of research focusing on prescription opioid misuse (POM) among adolescents and emerging adults (A/EAs) in the U.S. Given the rapidly changing nature of the opioid epidemic, we applied PRISMA Scoping Review (PRISMA-ScR) guidelines to identify empirical articles published in the past 5 years (January 2013-September 2018) from nine databases examining POM among A/EAs (ages 10-25) in the U.S. Seventy-six articles met our inclusion criteria focusing on POM in the following areas: cross-sectional surveys (n = 60), longitudinal cohort studies (n = 5), objective, non-self-reported data sources (n = 9), and interventions (n = 2). Final charted data elements were organized by methodology and sample, with results tables describing design, sample, interventions (where applicable), outcomes, and limitations. Most studies focused on the epidemiology of POM and risk/protective factors, including demographic (e.g., sex, race), individual (e.g., substance use, mental health), and social (e.g., peer substance use) factors. Despite annual national surveys conducted, longitudinal studies examining markers of initiation and escalation of prescription opioid misuse (e.g., repeated overdoses, time to misuse) are lacking. Importantly, few evidence-based prevention or early intervention programs were identified. Future research should examine longitudinal trajectories of POM, as well as adaptation and implementation of promising prevention approaches.

Prolonged ethanol administration prevents the development of tolerance to morphine-induced respiratory depression

BACKGROUND

Opioid users regularly consume other drugs such as alcohol (ethanol). Acute administration of ethanol can rapidly reverse tolerance to morphine-induced respiratory depression. However, alcohol consumption by opioid users is likely to occur over prolonged time periods. We have therefore sought to determine the effect of prolonged alcohol consumption on the development of tolerance to opioid respiratory depression.

METHODS

Mice were fed control or ethanol (5%) liquid diet for 16 days. On days 9-16 morphine tolerance was induced by administration of 3 priming injections of morphine followed by subcutaneous implantation of a morphine-filled osmotic mini-pump. Control mice received saline. Respiration was measured by plethysmography and the effect of an acute morphine challenge dose was measured on day 16 to assess the development of morphine tolerance.

RESULTS

Prolonged ethanol consumption for 14 days did not alter the respiratory depressant effect of an acute dose of morphine. Control mice treated with prolonged morphine developed tolerance to acute morphine respiratory depression whereas ethanol diet fed mice treated with prolonged morphine showed significant respiratory depression during morphine-pump treatment and remained sensitive to the respiratory depressant effect of the acute challenge dose of morphine. The ethanol consumption did not alter blood or brain levels of morphine, whilst conversely prolonged morphine treatment did not alter blood levels of ethanol.

CONCLUSIONS

Prolonged ethanol consumption prevents the development and maintenance of tolerance to the respiratory depressant effect of morphine. These data suggest that ethanol inhibition of tolerance will greatly increase the risk of fatal heroin overdose in humans.

Conditioned taste avoidance induced by the combination of heroin and cocaine: Implications for the use of speedball

Speedball (heroin + cocaine) is a prevalent drug combination among intravenous drug users. Although its use is generally discussed to be a function of changes in the rewarding effects of either or both drugs, changes in the aversive effects of either drug may also be impacted (weakened) by the combination. To address this latter possibility and its potential role in the use of speedball, the present studies examined the interaction of cocaine and heroin in taste avoidance conditioning. In Experiment 1, male Sprague-Dawley rats were given access to a novel saccharin solution and then injected with either vehicle or heroin (3.2 mg/kg, IP) followed immediately by various doses of cocaine (10, 18 or 32 mg/kg, SC). At the two lowest doses of cocaine, only animals injected with the drug combination (H + C) displayed a taste avoidance relative to control subjects (taste avoidance was induced with both the combination and the high dose of cocaine). At no dose did animals injected with the combination of heroin and cocaine drink more than animals injected with cocaine alone. In Experiment 2, male Sprague-Dawley rats were similarly treated but injected with vehicle or cocaine (10 mg/kg) followed by injections of various doses of heroin (1.8, 3.2, 5.6 or 10 mg/kg). At the three highest doses of heroin, only animals injected with the drug combination (C + H) displayed significant avoidance relative to control subjects (no avoidance was evident with the combination of cocaine and the low dose of heroin). At no dose did animals injected with the combination of cocaine and heroin drink more than animals injected with heroin alone. Together, these results suggest that the aversive effects of heroin and cocaine are not attenuated by co-administration by cocaine and heroin, respectively. The importance of this for the use of speedball was discussed.

Trends in Adolescent Heroin and Injection Drug Use in Nine Urban Centers in the U.S., 1999-2017

PURPOSE

Although estimates of heroin and injection drug use (IDU) among U.S. adolescents have remained low and stable, national data may mask local variation in use. Adolescent use may be higher in urban areas, many of which have historically high rates of heroin use and IDU. We investigate trends in heroin use and IDU among 9th-12th grade students in major urban centers in the U.S.

METHODS

We used local Youth Risk Behavior Survey data from all large, urban school districts (n = 9) with at least 5 years of weighted, publicly available data. We used time series mean estimation to estimate the prevalence of heroin use and IDU among high school students from 1999 to 2017 and used logistic regression to test for linear and quadratic trends.

RESULTS

We observed statistically significant linear increases in (1) lifetime heroin use in New York (β = .43, 1%-3.9%), Chicago (β = .15, 3.1%-4.6%), and Milwaukee (β = .35, 2.8%-7.4%); and (2) lifetime IDU in New York (β = .34, .8%-2.7%), Orange County (β = .17, 2.2%-3.5%), and Miami-Dade County (β = .16, 2.7%-3.9%). Only San Bernardino experienced significant decreases in heroin use (β = -.34, 4.6%-1.6%) and IDU (β = -.20, 2.5%-1.9%) over the time period.

CONCLUSIONS

In contrast to national trends, the prevalence of heroin use is increasing among adolescents in certain urban centers in the U.S. Our results illustrate that national averages mask local variation in adolescent heroin use. Further research with locally representative samples is needed to inform public health policy and practice, especially in cities where heroin problems have been historically endemic and continue to rise.

Perceived Risk of Heroin in Relation to Other Drug Use in a Representative US Sample

Low perception of risk is a risk factor for heroin use. Research is needed to determine whether this risk factor for heroin use is affected by the use of other drugs. Data were analyzed from participants in the 2015/2016 National Surveys on Drug Use and Health who denied lifetime heroin use (N= 110,102). We examined how recency of use of various drugs and number of drugs used relate to perceptions that using heroin is not a great risk. Results from multivariable models suggest that no lifetime drug use, and recent prescription opioid misuse and methamphetamine use, in particular, were associated with higher odds of perceiving that heroin use is not of great risk. Recent marijuana use was associated with lower odds of reporting that heroin use is not of great risk. Use of more drugs in one's lifetime, past year, and/or past month tended to be associated with lower odds of reporting heroin use as not a great risk. Prevention experts should consider that recent prescription opioid misuse in particular is a risk factor for the lower perception of risk, while individuals reporting no lifetime drug use may also require better education regarding harms associated with heroin use.

Examining the association between prescription opioid misuse and suicidal behaviors among adolescent high school students in the United States

Although some studies have examined the association between prescription opioid misuse and mental health outcomes, few studies have examined the effects of prescription opioid misuse on suicidal behaviors among adolescents. The objective of this study was to examine the association between prescription opioid misuse and suicidal ideation, suicide plan, and suicide attempt among adolescents. Data for this study came from the 2017 Youth Risk Behavior Surveillance System. A sample of 8830 adolescents aged 14-18 years (50.9% female) were analyzed using logistic regression with suicidal ideation, suicide plan, and suicide attempt as outcome variables and prescription opioid misuse as the main explanatory variable. Of the 8830 adolescents, 13.3% ever misused prescription opioids; 17.7% experienced suicidal ideation, 13.3% made a suicide plan, and 6.5% attempted suicide during the past 12 months. In the multivariate logistic regression models, adolescent students who misused prescription opioids were 1.50 times more likely to have experienced suicidal ideation, 1.44 times more likely to have made a suicide plan, and 1.58 times more likely to have attempted suicide during the past 12 months when compared to their counterparts who did not misuse prescription opioids. Other significant predictors of suicidal behaviors include sexual minority, history of sexual assault, traditional bullying and cyberbullying victimization, feeling sad or hopeless, cigarette smoking, and illicit drug use. The findings of the present study demonstrate the harmful effects of prescription opioid misuse and its association with suicidal behaviors among adolescents.

Sexual Orientation Disparities in Prescription Opioid Misuse Among U.S. Adults

INTRODUCTION

The opioid epidemic in the U.S. continues to increase in severity, and misuse of prescription opioids is of particular concern since it commonly precedes heroin use. This study examined whether sexual orientation (i.e., sexual identity and sexual attraction) is a risk factor for prescription opioid misuse and use disorder among a nationally representative sample of adults in the U.S.

METHODS

This study used data from adult participants (ages ≥18 years) in the 2015 National Survey on Drug Use and Health. Chi-square tests and logistic regression examined how sexual identity and sexual attraction relate to past-year and past-month prescription opioid misuse and past-year prescription opioid use disorder. Multivariable models examined associations controlling for demographic characteristics and other drug use. Gender-stratified analyses were also conducted. Data were analyzed in 2018.

RESULTS

In multivariable analyses, compared with those identifying as heterosexual, bisexual individuals were at 1.53 (95% CI=1.20, 1.97) and 1.66 (95% CI=1.14, 2.42) higher odds of reporting past-year and past-month misuse, respectively. In stratified analyses, female bisexuals remained at high risk. Regarding sexual attraction, compared with being attracted to only the opposite sex, being attracted to mostly the opposite sex (AOR=2.15, 95% CI=1.77, 2.63) or being equally attracted to both sexes (AOR=1.78, 95% CI=1.38, 2.30) were associated with higher odds for past-year opioid misuse. In stratified analyses, these associations were limited to females.

CONCLUSIONS

Sexual orientation disparities in opioid misuse and use disorder among a nationally representative sample of U.S. adults was found.