Polysubstance Use: A Broader Understanding of Substance Use During the Opioid Crisis

The psychedelic drug DOI reduces heroin motivation by targeting 5-HT2A receptors in a heroin and alcohol co-use model

There has been a recent renewed interest in the potential use of psychedelic drugs as therapeutics for certain neuropsychiatric disorders, including substance use disorders. The psychedelic drug 2,5-dimethoxy-4-iodoamphetamine (DOI) has demonstrated therapeutic efficacy in preclinical models of opioid use disorder (OUD). Alcohol is commonly co-used in individuals with OUD, but preclinical models that recapitulate this comorbidity are lacking. We developed a polydrug model wherein male and female rats were allowed to self-administer intravenous heroin and oral alcohol (or saccharin control solution) over weeks of behavioral training, and then we conducted a series of progressive ratio tests to assess the animals' motivational state for heroin and alcohol. In this model, motivation for heroin is higher than alcohol, and DOI (0.4 mg/kg) administered prior to testing significantly reduced heroin motivation measured as the animals' break point, or maximum effort the animal is willing to expend to obtain a single infusion of heroin. The 5-HT2A receptor antagonist MDL 100,907 (0.3 mg/kg), but not the 5-HT2C receptor antagonist SB-242084 (0.5 mg/kg), blocked the therapeutic effect of DOI on heroin motivation. No significant effects on alcohol break points were observed, nor did MDL 100,907 or SB-242084 have any effect on break points on their own. These data support the view that psychedelic drugs like DOI may have therapeutic effects on opioid use in individuals with OUD and comorbid alcohol use, by acting as a 5-HT2A receptor agonist.

Explaining the causes and motivations for multiple substance use from the perspectives of users and therapists: A qualitative study

Background

The high prevalence of multiple substance use (MSU) is concerning, given the weak awareness about this issue and the potential impact this unawareness has on the severity of substance use disorder (SUD) and treatment outcomes. The aim of this study is to identify and elucidate the causes and motivations for MSU from the viewpoints of users and therapists in this field.

Methods

In this qualitative study, the conventional content analysis approach and purposive sampling were utilized. Deep semi-structured exploratory interviews were conducted with 17 substance users and 8 addiction therapists (including 4 psychiatrists, 3 general practitioners, and 1 psychologist). Field notes were also taken to identify and explain the motivations and reasons for MSU from the perspectives of users and therapists. The data were analyzed comparatively and simultaneously using the method suggested by Graneheim and Lundman (2004).

Results

Based on the findings of this study, the motivations for MSU are reflected in four main categories: 'Pharmacological factors' with subcategories such as achieving desired states and mitigating the undesirable effects of substances through leveraging the balancing, synergistic, and antagonistic effects of substances, substituting the effects of other substances, self-medication of the undesirable effects of other substances, enhancing the overall consumption experience such as heightened peak experience and enhanced pleasure, moderating the come-down, and seeking euphoria experiences in different substances; 'Biological factors' with subcategories including different neurobehavioral systems, individual differences determining substance dependence and the somatic-neural vulnerability of consumers; 'Psychosocial factors' with the subcategories of undesirable norms like the need for acceptance and social interactions, the context of substance use, consumers' experiences and expectations of substance use, and the maladaptive personality traits of consumers; and 'Addiction's inevitability' with the subcategories of coercion and the need to maintain equilibrium, and the difficulties of substance detoxification.

Conclusion

The motivations behind Multiple Substance Use (MSU) behaviors are multifaceted, including pharmacological, biological, psychosocial, and addiction-related factors. Recognizing and comprehending the interplay between these factors and motivations can inform better prevention strategies, assessment of treatment needs, and enhancement of treatment outcomes for individuals dealing with MSU.

Study protocol for a randomized controlled trial to adapt a posttraumatic stress disorder intervention of patients with opioid-stimulant polysubstance use receiving methadone maintenance treatment

BACKGROUND

The purpose of the Treatment for Harnessing Resiliency, Improving emotional regulation, and empowering indiViduals for a brighter future (THRIVE) study is to adapt an evidence-based posttraumatic stress disorder (PTSD) treatment for use among a polysubstance population receiving methadone maintenance treatment (MMT) at an opioid treatment program. Polysubstance use of high-risk combinations, such as illicit opioids and stimulants, is a critical public health issue. Individuals who engage in these high-risk combinations are more likely to have histories of childhood trauma, multiple traumas, PTSD, and greater PTSD severity as compared to mono-substance using individuals. Trauma, co-morbid mental health disorders such as PTSD, and polysubstance use complicate treatment outcomes. This study will use eight study phases to adapt an existing evidence-based PTSD intervention, Skills Training in Affective and Interpersonal Regulation with Narrative Therapy (STAIR-NT), via a massed treatment model (i.e., condensed treatment schedule) for patients in MMT who are engaged in sustained opioid-stimulant polysubstance use.

METHODS AND ANALYSIS

The intervention is an adapted version of the STAIR-NT protocol. The massed version created includes four 60-min sessions of skill building and two weeks of four 60-min sessions of narrative therapy. A preliminary randomized controlled trial (RCT) with 80 participants, randomized 1:1, will be conducted to assess the intervention's implementation and impact on primary short-term outcomes of polysubstance use and PTSD symptoms.

ETHICS AND DISSEMINATION

The results of this study will inform a fully-powered effectiveness trial for individuals with PTSD and polysubstance use receiving MMT. The findings are expected to provide valuable insights into improving both PTSD and substance use outcomes, and real-world implementation insights to integrating trauma-informed care in treatment settings for vulnerable populations.

REGISTRATION

This study is registered at ClinicalTrials.Gov as NCT06307340. Registration date 03/2024.

Trajectories of polysubstance use: Are past-year internalizing and externalizing problems associated with trajectories of polysubstance use over time?

OBJECTIVE

Polysubstance use among adults has been a public health concern in the U.S. and is associated with adverse consequences. This study aimed to identify the longitudinal trajectory of polysubstance use and test whether internalizing and externalizing problems predict it.

METHODS

Data of adults aged 18 and older (N = 15076) were extracted from the Waves 1-5 Population Assessment of Tobacco and Health Study (2013-2019). Group-Based Trajectory Modeling was performed to identify the trajectory of polysubstance use. Examined substances included use of cigarettes, e-cigarettes, excessive alcohol, cannabis, painkillers, and cocaine in past 30 days from all waves. Weighted multinomial logistic regressions were conducted to investigate the associations between internalizing and externalizing problems and the trajectory of polysubstance use, controlling for demographic variables.

RESULTS

Five trajectory groups were identified: (1) No to minimal polysubstance use risk (45.6 %); (2) Polysubstance use-low risk (10.7 %); (3) Cigarette-leading polysubstance use-high risk (23.5 %); (4) Cigarette-cannabis co-leading polysubstance use-high risk (12.3 %); and (5) Cannabis-leading polysubstance use-high risk (7.8 %). Compared with Group 1, higher internalizing problems predicted the membership of Group 3 [Relative risk ratio (RRR) range: 1.07-1.17] and Group 4 (RRR range: 1.04-1.21). Compared with Group 1, higher externalizing problems predicted the membership of Group 5 (RRR range: 1.01-1.10).

CONCLUSIONS

Prevention efforts should consider internalizing problems and associated trajectories of high-risk polysubstance use (e.g., cigarette-leading and cigarette-cannabis co-leading) as well as externalizing problems and associated trajectories of high-risk polysubstance use (e.g., cannabis-leading), when designing interventions to prevent polysubstance use.

Characterizing Individuals Who Elect and Decline Opioid Overdose Education and Naloxone Distribution to Tailor Programs and Expand Impact

BACKGROUND

In response to the opioid epidemic, federal agencies have stressed the importance of targeted naloxone distribution through avenues such as Opioid Overdose Education and Naloxone Distribution (OEND). OEND effectively reduces mortality by training laypersons to respond to overdose situations. Despite demonstrated effectiveness, OEND remains underutilized. This project aimed to characterize those who illicitly use opioids to determine avenues for future tailoring of OEND programs.

METHODS

Individuals who illicitly used opioids within the past 6 months were recruited via online social media. Participants completed an online questionnaire that assessed history of opioid use and were given the option to receive opioid overdose and naloxone administration training. Those who elected training (n = 111) and those who declined (n = 193) were compared on opioid use, severity of use, and overdose experiences.

RESULTS

Participants (N = 304) were 47% male and 83% White. Tests of between group differences with measures of effect size were used for analyses. Those who elected training endorsed greater intravenous administration (χ2 = 4.18, P = 0.041, Cramer's V = 0.12). Individuals who declined training reported more frequent nonprescribed methadone use (χ2 = 7.51, P = 0.006, Cramer's V = 0.16), overdose hospitalizations (t(298) = 2.13, P = 0.034, Cohen's d = 0.26), and observed overdoses (t(300) = 3.01, P = 0.003, Cohen's d = 0.36). After adjusting for multiple comparisons, only the differences in nonprescribed methadone use and observed overdoses remained statistically significant.

CONCLUSIONS

Individuals who declined training were more likely to report ever use of nonprescribed methadone and having witnessed others overdose. They may have had greater exposure to naloxone, hence decreasing perceived need for training. Understanding characteristics of those who elect and refuse training could inform structuring of programs and recruitment approaches.

Improving Estimates of the Prevalence of Opioid Use Disorder in the United States: Revising Keyes et al

OBJECTIVES

The United States faces an ongoing drug overdose crisis, but accurate information on the prevalence of opioid use disorder (OUD) remains limited. A recent analysis by Keyes et al used a multiplier approach with drug poisoning mortality data to estimate OUD prevalence. Although insightful, this approach made stringent and partly inconsistent assumptions in interpreting mortality data, particularly synthetic opioid (SO)-involved and non-opioid-involved mortality. We revise that approach and resulting estimates to resolve inconsistencies and examine several alternative assumptions.

METHODS

We examine 4 adjustments to Keyes and colleagues' estimation approach: (A) revising how the equations account for SO effects on mortality, (B) incorporating fentanyl prevalence data to inform estimates of SO lethality, (C) using opioid-involved drug poisoning data to estimate a plausible range for OUD prevalence, and (D) adjusting mortality data to account for underreporting of opioid involvement.

RESULTS

Revising the estimation equation and SO lethality effect (adj. A and B) while using Keyes and colleagues' original assumption that people with OUD account for all fatal drug poisonings yields slightly higher estimates, with OUD population reaching 9.3 million in 2016 before declining to 7.6 million by 2019. Using only opioid-involved drug poisoning data (adj. C and D) provides a lower range, peaking at 6.4 million in 2014-2015 and declining to 3.8 million in 2019.

CONCLUSIONS

The revised estimation equation presented is feasible and addresses limitations of the earlier method and hence should be used in future estimations. Alternative assumptions around drug poisoning data can also provide a plausible range of estimates for OUD population.

Exogenous Opioids and the Human Endocrine System: An Endocrine Society Scientific Statement

The use and misuse of opioids are a growing global problem. Although the effects of these drugs on the human endocrine system have been studied for decades, attention on their related clinical consequences, particularly on the hypothalamic-pituitary system and bone health, has intensified over recent years. This Statement appraises research data related to the impact of opioids on the gonadal and adrenal function. Whereas hypogonadism is well recognized as a side effect of opioids, the significance of their inhibitory actions on the hypothalamic-pituitary-adrenal system and the occurrence of clinically relevant adrenal insufficiency is not fully elucidated. The often-inconsistent results of studies investigating how opioids affect the secretion of GH, prolactin, arginine vasopressin, and oxytocin are assessed. The accumulating evidence of opioid actions on bone metabolism and their negative sequelae on bone mineral density and risk of fracture are also reviewed. In each section, available data on diagnostic and management approaches for opioid endocrine sequelae are described. This Statement highlights a plethora of gaps in research associated with the effects and clinical consequences of opioids on the endocrine system. It is anticipated that addressing these gaps will improve the care of people using or misusing opioids worldwide. The Statement is not intended to serve as a guideline or dictate treatment decisions.

Fentanyl self-administration is accelerated by methamphetamine co-use and results in worsened hypodopaminergia in male, but not female rats

Combined use of fentanyl and methamphetamine (FENT + METH) has increased in recent years and has been documented in a growing number overdose deaths each year. The impact of FENT + METH on behavior and neurobiology is not well understood. In this study, male and female Long Evans rats were tested on a limited access, fixed ratio 1 self-administration schedule for increasing doses (1.25-5 μg/kg/infusion; iv) of fentanyl, with and without a single dose (0.1 mg/kg/infusion; iv) of methamphetamine, for 15 days. FENT + METH abolished dose responsiveness to fentanyl in all rats and accelerated intake in males, resulting in patterns of responding that may be more likely to result in adverse effects. Ex vivo slice voltammetry in the nucleus accumbens core showed decreases in dopamine release and reuptake (Vmax) following FENT + METH exposure, compared with saline, fentanyl, and methamphetamine alone groups at baseline parameters. Further, significant decreases in dopamine release were observed across a range of stimulation intensities following FENT + METH exposure. Overall, male and female rats displayed sex-specific behavioral and neurobiological responses to FENT + METH exposure, with males displaying increased vulnerability.

Sleep-related impairment among people who use opioids: The critical role of structural vulnerability

OBJECTIVE

People who use opioids are vulnerable to sleep disturbances due to a range of factors, including the substances they use and the various structural vulnerabilities they face. We aimed to understand the burden of sleep-related impairment and problems pertaining to sleep context and schedule among people who use opioids.

METHODS

We explored sleep quality and problems among a suburban sample of people who use opioids experiencing extensive structural vulnerabilities (N = 170). Participants reported their most urgent concern in the past week (e.g., sleep, drug use, housing), their sleep context, sleep problems, sleep schedules, and scores on the PROMIS Sleep-Related Impairment measure. We then quantified associations between Sleep-Related Impairment scores and sociodemographics and substance use.

RESULTS

Participants were primarily men (66%) and non-Hispanic Black (67%) with a mean age of 42 (SD: 12.1). Many experienced hunger (44%) and literal homelessness (40%). One-quarter (28%) reported that sleep was their most urgent concern in the past week. The most common problems when falling or staying asleep were mental health-related symptoms (81%) and pain/discomfort (32%). Literal homelessness (β = 2.2, 95% CI: 0.6, 3.7), hunger (β = 2.3, 95% CI: 1.0, 3.6), and frequent alcohol use (β = 1.5, 95% CI: 0.2, 2.7) were significantly associated with Sleep-Related Impairment scores.

CONCLUSIONS

Homelessness and hunger are associated with sleep-related impairment in people who use opioids. Poor sleep quality, substance use, structural vulnerability, and mental health problems are all interrelated sources of functional impairment in this population. Interventions that address poverty as an underlying cause of sleep-related impairment and provide safe sleeping environments are needed.

Initiation and/or re-initiation of drug use among people who use drugs in Vancouver, Canada from 2021 to 2022: a prospective cohort study

OBJECTIVES

Widespread health service disruptions resulting from the COVID-19 pandemic coincided with a dramatic increase in overdose deaths among people who use drugs (PWUD) in Vancouver, Canada. Those with a history of injection drug use are known to be at heightened risk of substance-associated harms. Drug use patterns and associated sociodemographic and health care utilization trends have been understudied in this population since the pandemic onset. We sought to understand patterns of drug use initiation and/or re-initiation among people with a history of injection drug use (IVDU).

METHODS

Data were obtained from three harmonized prospective cohort studies of PWUD in Vancouver. Participants with a lifetime history of IVDU who responded to a survey between June 2021 and May 2022 were included. The primary outcome variable was a composite of substance use initiation and re-initiation over the study period, labelled as drug (re)-initiation. A multivariable generalized linear mixed-effects model was used to examine factors associated with self-reported (re)-initiation of substance use over the past six months.

RESULTS

Among 1061 participants, the median age was 47 years at baseline and 589 (55.5%) identified as men. In total, 183 (17.2%) participants reported initiating and/or re-initiating a drug, with 44 (4.1%) reporting new drug initiation and 148 (14.0%) reporting drug re-initiation (9 participants responded 'yes' to both). Overall, unregulated stimulants (e.g., crystal methamphetamine and cocaine) were the most common drug class (re-)initiated (n = 101; 55.2%), followed by opioids (n = 74; 40.4%) and psychedelics (n = 36; 19.7%). In the multivariable analysis, (re-)initiation of drug use was independently associated with recent IVDU (adjusted odds ratio [AOR] 2.62, 95% confidence interval [CI] 1.02, 6.76), incarceration (AOR 3.36, CI 1.12, 10.14) and inability to access addiction treatment (AOR 4.91, 95% CI 1.22, 19.75).

CONCLUSIONS

In an era impacted by the intersecting effects of the COVID-19 pandemic and the overdose crisis, nearly one in five PWUD with a history of IVDU began using a new drug and/or re-started use of a previous drug. Those who reported drug (re-)initiation exhibited riskier substance use behaviours and reported difficulty accessing treatment services. Our findings underscore the need to provide additional resources to support this high-risk population.

Comparison of Treatment Receipt and Hospitalization Among Patients With Stimulant Use Disorder and/or Opioid Use Disorder in the Veterans Health Administration

OBJECTIVES

Stimulant use is a growing problem, but little is known about service utilization among patients with stimulant use disorder (StUD). In the context of the overdose crisis, much research has focused on patients with opioid use disorder (OUD). It is unclear how the characteristics, treatment receipt, and hospitalization of patients with StUD differ from patients with OUD.

METHODS

Electronic health record data were extracted for national Veterans Health Administration patients with a visit from March 1, 2020, to February 28, 2021 with StUD and/or OUD (N = 132,273). We compared patients with StUD without OUD to those with (1) co-occurring StUD + OUD and (2) OUD without StUD. Patient characteristics, substance use disorder treatment, and hospitalizations in the year following patients' first study period visit were descriptively compared. Treatment and hospitalization were also compared in adjusted regression models.

RESULTS

Compared with patients with OUD + StUD, those with StUD without OUD were less likely to receive outpatient (adjusted odds ratio [aOR] 0.49, 95% confidence interval [CI] 0.47-0.50) or any treatment (aOR 0.47, 95% CI 0.46-0.49). Compared with patients with OUD without StUD, those with StUD without OUD were less likely to receive outpatient (aOR 0.51, 95% CI 0.49-0.52) or any treatment (aOR 0.56, 95% CI 0.54-0.58) and more likely to receive residential treatment (aOR 2.18, 95% 2.05-2.30) and to be hospitalized (aOR 1.62, 95% 1.56-1.69).

CONCLUSIONS

Patients with StUD may be less likely to receive treatment and more likely to be hospitalized than patients with OUD. Efforts focused on mitigating hospitalization and increasing treatment receipt for patients with StUD are needed.

Evolution of the substance use landscape: Implications for contingency management

Contingency management (CM), which involves the delivery of incentives upon meeting behavioral goals, has the potential to improve substance use treatment outcomes. The intervention allows for flexibility through numerous modifiable components including changes to incentive magnitude and schedule, target behavior, and intervention structure. Unfortunately, numerous changes in the substance use landscape have occurred in the past 10 to 15 years: Substances are more potent, overdose risk has increased, new substances and methods of use have been introduced, and substance classes are increasingly being intentionally and unintentionally mixed. These developments potentially undermine CM outcomes. We explored recent substance use changes due to legislative, regulatory, social, and economic factors for four substance classes: stimulants, opioids, tobacco, and cannabis. We discuss potential adjustments to the modifiable components of CM for future research in response to these changes. By continually adapting to the shifting substance use landscape, CM can maintain optimal efficacy.

Factors associated with suicidal ideation among people with HIV engaged in care

BACKGROUND

People with HIV (PWH) are at elevated risk for suicidal ideation (SI), yet few studies have examined how substance use, clinical and sociodemographic factors are associated with SI among PWH.

METHOD

We used substance use (Tobacco, Alcohol, Prescription Medication, and Other Substance Use [TAPS]) and depression (PHQ-9) data from computerized screening of adult PWH in primary care clinics in Northern California, combined with health record data on psychiatric diagnoses, HIV diagnosis, treatment, and control (HIV RNA, CD4), insurance, and neighborhood deprivation index (NDI) to examine factors associated with SI (PHQ-9 item 9 score > 0). Adjusted odds ratios (aOR) for SI were obtained from logistic regression models.

RESULTS

Among 2829 PWH screened (92 % male; 56 % white; mean (SD) age of 54 (13) years; 220 (8 %) reported SI. Compared with no problematic use, SI was higher among those reporting one (aOR = 1.65, 95 % CI = 1.17, 2.33), two (aOR = 2.23, 95 % CI = 1.42, 3.49), or ≥ 3 substances (aOR = 4.49, 95 % CI = 2.41, 8.39). SI risk was higher for those with stimulant use (aOR = 3.55, 95 % CI = 2.25, 5.59), depression (aOR = 4.18, 95 % CI = 3.04, 5.74), and anxiety diagnoses (aOR = 1.67, 95 % CI = 1.19, 2.34), or Medicaid (aOR = 2.11, 95%CI = 1.24, 3.60) compared with commercial/other insurance. SI was not associated with HIV-related measures or NDI.

LIMITATIONS

SI was assessed with a single PHQ-9 item. Simultaneous SI and exposure data collection restricts the ability to establish substance use as a risk factor.

CONCLUSIONS

HIV care providers should consider multiple substance use, stimulant use, depression or anxiety, and public insurance as risk factors for SI and provide interventions when needed.

Public Perception Towards Drug Abuse in South Korea: The Effects of Overconfidence and Affirmation

OBJECTIVE

The abuse of prescription drugs and over-the-counter medicines has been a major issue addressed as a serious public health problem worldwide. This study explored factors contributing to substance abuse in Korea by examining the status of substance abuse among Korean adults and evaluating their knowledge, attitudes, and intentions toward substance abuse.

METHODS

Data were collected online from a sample of participants 19 years old or older from May 20 to June 1, 2020 (n=1,020). The survey consisted of questions on demographics, perceptions of drug risk, motives for drug use, and attitudes toward drug addiction treatment. Principal component and multiple logistic regression analyses were used to explore the factors contributing to the perception of drug abuse.

RESULTS

In the multivariate regression analysis, overconfidence in handling drug usage, acceptance of addictive substances, and affirmation of public support for drug abuse were associated with opioid abuse (Nagelkerke R2=0.486), and additionally affirmation of legal cannabis usage and motivation to use diet pills were associated with diet pill abuse (Nagelkerke R2=0.569).

CONCLUSION

The findings of this study suggest that the actual situation of substance abuse among Korean adults increases awareness of and attitudes toward drug use related to substance abuse.

Decoding Suicide Decedent Profiles and Signs of Suicidal Intent Using Latent Class Analysis

Importance

Suicide rates in the US increased by 35.6% from 2001 to 2021. Given that most individuals die on their first attempt, earlier detection and intervention are crucial. Understanding modifiable risk factors is key to effective prevention strategies.

Objective

To identify distinct suicide profiles or classes, associated signs of suicidal intent, and patterns of modifiable risks for targeted prevention efforts.

Design, Setting, and Participants

This cross-sectional study used data from the 2003-2020 National Violent Death Reporting System Restricted Access Database for 306 800 suicide decedents. Statistical analysis was performed from July 2022 to June 2023.

Exposures

Suicide decedent profiles were determined using latent class analyses of available data on suicide circumstances, toxicology, and methods.

Main Outcomes and Measures

Disclosure of recent intent, suicide note presence, and known psychotropic usage.

Results

Among 306 800 suicide decedents (mean [SD] age, 46.3 [18.4] years; 239 627 males [78.1%] and 67 108 females [21.9%]), 5 profiles or classes were identified. The largest class, class 4 (97 175 [31.7%]), predominantly faced physical health challenges, followed by polysubstance problems in class 5 (58 803 [19.2%]), and crisis, alcohol-related, and intimate partner problems in class 3 (55 367 [18.0%]), mental health problems (class 2, 53 928 [17.6%]), and comorbid mental health and substance use disorders (class 1, 41 527 [13.5%]). Class 4 had the lowest rates of disclosing suicidal intent (13 952 [14.4%]) and leaving a suicide note (24 351 [25.1%]). Adjusting for covariates, compared with class 1, class 4 had the highest odds of not disclosing suicide intent (odds ratio [OR], 2.58; 95% CI, 2.51-2.66) and not leaving a suicide note (OR, 1.45; 95% CI, 1.41-1.49). Class 4 also had the lowest rates of all known psychiatric illnesses and psychotropic medications among all suicide profiles. Class 4 had more older adults (23 794 were aged 55-70 years [24.5%]; 20 100 aged ≥71 years [20.7%]), veterans (22 220 [22.9%]), widows (8633 [8.9%]), individuals with less than high school education (15 690 [16.1%]), and rural residents (23 966 [24.7%]).

Conclusions and Relevance

This study identified 5 distinct suicide profiles, highlighting a need for tailored prevention strategies. Improving the detection and treatment of coexisting mental health conditions, substance and alcohol use disorders, and physical illnesses is paramount. The implementation of means restriction strategies plays a vital role in reducing suicide risks across most of the profiles, reinforcing the need for a multifaceted approach to suicide prevention.

Prevalence of comorbid substance use disorders among people with opioid use disorder: A systematic review & meta-analysis

BACKGROUND

Comorbid substance use disorders (SUDs) among people with opioid use disorder (OUD) contribute to poor clinical outcomes, including overdose and mortality. We present the first systematic review and meta-analysis to estimate the prevalence of specific non-opioid SUDs among people with OUD.

METHODS

We searched Embase, PsycINFO, and MEDLINE from 1990 to 2022 for studies that used Diagnostic and Statistical Manual of Mental Disorders (DSM) or International Classification of Diseases (ICD) criteria to assess the prevalence of non-opioid SUDs among individuals with OUD. We used random-effects meta-analyses with 95% Confidence Intervals (CIs) to pool current and lifetime prevalence estimates separately. Meta-regressions and stratified meta-analyses were used to examine differences in prevalence estimates by sample characteristics and methodological factors.

RESULTS

Of the 36,971 publications identified, we included data from 194 studies and 77,212 participants with OUD. The prevalence of any comorbid SUD among people with OUD was 59.5% (95%CI 49.1-69.5%) for current non-opioid SUDs, with 72.0% (95%CI 52.5-87.9%) experiencing a comorbid SUD in their lifetime. Of the studies that examined current comorbid SUDs, cocaine use disorder (30.5%, 95%CI 23.0-38.7%) was most common, followed by alcohol (27.1%, 95%CI 24.4- 30.0%), cannabis (22.7%, 95%CI 19.0-26.6%), sedative (16.1%, 95%CI 13.1-19.3%), and methamphetamine (11.4%, 95%CI 6.8-17.1%) use disorders. Substantial heterogeneity (I2>90%) across estimates was observed. Substantial heterogeneity (I2>90%) was observed across estimates, with significant variations in prevalence identified across geographic locations, recruitment settings, and other study-level factors.

CONCLUSION

Findings from this study emphasize the importance of comorbid SUD treatment access for people with OUD. Our estimates can inform the provision of treatment and harm reduction strategies for people with OUD and specific subpopulations.

Heart Rate Variability in Adults With Substance Use Disorder: A Comprehensive Narrative Review

BACKGROUND

Heart rate variability (HRV) is an indicator of autonomic abnormalities. However, little is known about the role of HRV related to substance use behavior and the association between the changes in HRV and signs of relapse in substance use.

AIM

The purpose of this study was to review the existing literature on autonomic response to substance use (i.e., opioids, cocaine, and methamphetamine) measured by HRV and its outcomes related to the risk factors of relapse.

METHODS

A systematic search of the literature was conducted using PubMed, PsychINFO, and Ovid Medline databases. The study includes full-text articles published in English from 2010 to 2020, using measures of HRV in human subjects who use substances.

RESULTS

A total of 14 studies were reviewed. Studies included outpatients with a prescription or nonprescription opioid misuse behavior with a primary diagnosis being chronic pain or substance use disorder (SUD). Significantly decreased resting HRV was found in substance users compared to healthy controls. Lower resting HRV has been significantly associated with stress, craving, and greater symptom severities in individuals with SUD and other substance dependence. HRV indices can be potential measures of homeostatic imbalance and self-regulation flexibility.

CONCLUSION

HRV may be a useful tool for monitoring early indication of relapse so that relapse prevention measures can be implemented in a timely manner. Future studies in substance use may benefit from examining HRV in relations to substance use and relapse signs and symptoms in a larger population to guide future relapse prevention strategies.

Integrative Pharmacology in the Treatment of Substance Use Disorders

The detrimental physical, mental, and socioeconomic effects of substance use disorders (SUDs) have been apparent to the medical community for decades. However, it has become increasingly urgent in recent years to develop novel pharmacotherapies to treat SUDs. Currently, practitioners typically rely on monotherapy. Monotherapy has been shown to be superior to no treatment at all for most substance classes. However, many randomized controlled trials (RCTs) have revealed that monotherapy leads to poorer outcomes when compared with combination treatment in all specialties of medicine. The results of RCTs suggest that monotherapy frequently fails since multiple dysregulated pathways, enzymes, neurotransmitters, and receptors are involved in the pathophysiology of SUDs. As such, research is urgently needed to determine how various neurobiological mechanisms can be targeted by novel combination treatments to create increasingly specific yet exceedingly comprehensive approaches to SUD treatment. This article aims to review the neurobiology that integrates many pathophysiologic mechanisms and discuss integrative pharmacology developments that may ultimately improve clinical outcomes for patients with SUDs. Many neurobiological mechanisms are known to be involved in SUDs including dopaminergic, nicotinic, N-methyl-D-aspartate (NMDA), and kynurenic acid (KYNA) mechanisms. Emerging evidence indicates that KYNA, a tryptophan metabolite, modulates all these major pathophysiologic mechanisms. Therefore, achieving KYNA homeostasis by harmonizing integrative pathophysiology and pharmacology could prove to be a better therapeutic approach for SUDs. We propose KYNA-NMDA-α7nAChRcentric pathophysiology, the "conductor of the orchestra," as a novel approach to treat many SUDs concurrently. KYNA-NMDA-α7nAChR pathophysiology may be the "command center" of neuropsychiatry. To date, extant RCTs have shown equivocal findings across comparison conditions, possibly because investigators targeted single pathophysiologic mechanisms, hit wrong targets in underlying pathophysiologic mechanisms, and tested inadequate monotherapy treatment. We provide examples of potential combination treatments that simultaneously target multiple pathophysiologic mechanisms in addition to KYNA. Kynurenine pathway metabolism demonstrates the greatest potential as a target for neuropsychiatric diseases. The investigational medications with the most evidence include memantine, galantamine, and N-acetylcysteine. Future RCTs are warranted with novel combination treatments for SUDs. Multicenter RCTs with integrative pharmacology offer a promising, potentially fruitful avenue to develop novel therapeutics for the treatment of SUDs.

Substance use patterns, quantities, and associated risk factors in women with polysubstance misuse

Polysubstance use (PSU), the use of two or more substances proximally, is highly prevalent and has amplified the risk for morbidity and mortality. However, PSU patterns and associated risk factors are not well characterized. This may be especially relevant to women who are known to be vulnerable to stress/trauma, craving, pain, and anxious and depressive symptoms as associated risk factors for PSU. A cross-sectional observational study was conducted to characterize substance use patterns in women who regularly used cocaine, opioids, marijuana, alcohol, benzodiazepines and/or nicotine and were being assessed for a placebo-controlled study of guanfacine treatment (n = 94; ages 19-65). Data on stress/traumatic life events, drug cravings for each substance, pain ratings, and anxiety and depressive symptoms were also obtained using standardized well-validated surveys. High use per day of two or more drugs was observed (72.7% ± 33.3%) and opioid amounts were high relative to other drug amounts (p's < 0.001). Notably, higher stress/trauma events and higher cravings are each associated with cumulative PSU days, amounts and probability of an individual PSU day (p's < 0.02). This remained when PSU versus single substance use was compared. Pain, anxiety and depressive symptoms were not associated with PSU metrics. These findings characterize specific patterns of PSU in women and show that average drug craving and stress/trauma events are associated with PSU. Interventions that focus on stress/trauma and craving management could be of benefit in reducing PSU risk in women.

Longitudinal patterns of use of stimulants and opioids in the AIDS linked to the IntraVenous experience cohort, 2005-2019

BACKGROUND

Overdoses involving opioids and stimulants are on the rise, yet few studies have examined longitudinal trends in use of both substances. We sought to describe use and co-use of opioids and stimulants, 2005-2019, in the AIDS Linked to the Intravenous Experience (ALIVE) cohort - a community-based cohort of people with a history of injection drug use living in or near Baltimore, MD.

METHODS

We included 2083 ALIVE participants, who had at least two visits during the study period. Our outcome was based on self-reported use of opioids and stimulants in the prior 6 months. We estimated prevalence of 4 categories of use (neither stimulants nor opioids, only stimulants, only opioids, stimulants and opioids), using a non-parametric multi-state model, accounting for the competing event of death and weighting for informative loss to follow-up. All analyses were stratified by enrollment cohort, with the main analysis including participants who enrolled prior to 2015 and a sub-analysis including participants who enrolled 2015-2018.

RESULTS

In the main analysis, prevalence of using stimulants and opioids decreased from 38 % in 2005 to 12 % 2013 but stabilized from 2014 onwards (13-19 %). The prevalence of using only stimulants (7-11 %) and only opioids (5-10 %) was stable across time. Participants who reported using both were more likely to report homelessness, depression, and other substance use (e.g., marijuana and heavy alcohol use) than participants in the other use categories. On average, 65 % of visits with use of both were followed by a subsequent visit with use of both; of participants transitioning out of using both, 13% transitioned to using neither.

CONCLUSIONS

While use of stimulants and opioids declined in the cohort through 2013, a meaningful proportion of participants persistently used both. More research is needed to understand and develop strategies to mitigate harms associated with persistent use of both stimulants and opioids.

Nativity and the risk of opioid use disorder among Hispanic/Latinx women in primary care in Los Angeles, CA

BACKGROUND

While rates of opioid use disorder (OUD) are lower among women compared to men, nativity may have disproportionate impacts on OUD risk among Hispanic/Latinx women but remain understudied.

OBJECTIVE

To assess the association between country of birth and reported OUD risk among low-income Hispanic/Latinx women in primary care in Los Angeles, CA.

METHODS

This was a cross-sectional study of 1189 non-pregnant, Hispanic/Latinx women attending two federally qualified health centers in Los Angeles between March and July 2013. OUD risk was assessed using the Alcohol, Smoking, and Substance Involvement Screening Test (ASSIST), and moderate-to-high risk was defined as ASSIST score ≥ 4.

RESULTS

Overall, 4.2% of women (n = 49) were at moderate-to-high risk for OUD. Risk for OUD was higher among US-born women compared to foreign-born women (6.7 vs. 1.7%; p < .01), those who reported 2+ chronic medical conditions (p < .01), and those who were at moderate-to-high risk for other substance use disorders (p < .01). In multivariable logistic regression analyses, being U.S.-born was independently associated with being at moderate-to-high risk for OUD among Hispanic/Latinx women as compared to those who were foreign-born (AOR = 2.8; 95% CI 1.2-6.8).

CONCLUSION

Among low-income Hispanic/Latinx women presenting to primary care, one in twenty patients is at-risk for OUD. The odds of moderate-high risk of OUD were three times as high in US-born compared to foreign-born women, and higher among those with chronic medical conditions and those at risk of other substance use disorders. Gender-specific and culturally-tailored screening for OUD may inform overdose prevention interventions for US-born Hispanic/Latinx women.

Predicting first use of heroin from prescription opioid use subtypes: Insights from the Monitoring the Future longitudinal panel

BACKGROUND

Only a small proportion of individuals who initiate nonmedical use of prescription opioids (NUPO) transition to heroin, suggesting that more nuanced aspects of NUPO may be better indicators of risk for escalating opioid use trajectories. This study leveraged panel data to identify NUPO typologies based on NUPO characteristics associated with opioid risk trajectories (route of administration, motives) and compared rates of heroin initiation at follow-up across typologies.

METHODS

Latent class analyses were run among respondents with no history of heroin use from the Monitoring the Future Panel Study (base year N=10,408) at modal ages 18, 19/20, 21/22, 23/24, and 25/26. Indicators included oral NUPO, nonoral NUPO, and NUPO motives to experiment, have a good time with friends, get high, escape problems, manage pain, relax, and sleep. Heroin initiation at follow-ups through modal age 29/30 was predicted from class membership.

RESULTS

No NUPO, self-medication (oral, manage pain), recreational (oral, nonoral, experiment, get high, have a good time with friends), and mixed-motive (all routes, all motives) classes emerged. Heroin initiation rates did not differ across no NUPO and self-medication classes; recreational and mixed-motives classes initiated heroin at higher rates than the other classes and comparable rates to each other. Non-NUPO drug use prior to heroin initiation was prevalent in recreational and mixed-motive classes.

CONCLUSIONS

NUPO does not uniformly or uniquely increase risk for heroin initiation. Leveraging more nuanced indicators of risk for heroin use and targeting polysubstance use in addition to opioid-specific programming may enhance the efficacy of public health efforts.

Novel Therapeutic and Program-Based Approaches to Opioid Use Disorders

Opioid use disorder continues to drive overdose deaths in many countries, including the United States. Illicit fentanyl and its analogues have emerged as key contributors to the complications and mortality associated with opioid use disorder. Medications for opioid use disorder treatment, such as methadone and buprenorphine, are safe and substantially reduce opioid use, infectious complications, and mortality risk, but remain underutilized. Polysubstance use and emerging substances such as xylazine and designer benzodiazepines create additional treatment challenges. Recent clinical and policy innovations in treatment delivery, including telemedicine, bridge clinics, and expanded models for accessing methadone have the potential to increase access to life-saving care for people living with opioid use disorder.

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.

Polysubstance mortality trends in White and Black Americans during the opioid epidemic, 1999-2018

BACKGROUND

Psychoactive drug combinations are increasingly contributing to overdose deaths among White and Black Americans. To understand the evolving nature of overdose crisis, inform policies, and develop tailored and equitable interventions, this study provides a comprehensive assessment of polysubstance mortality trends by race and sex during the opioid epidemic.

METHODS

We used serial cross-sectional US mortality data for White and Black populations from 1999 through 2018 to calculate annual age-adjusted death rates (AADR) involving any opioid, opioid subtypes, benzodiazepines, cocaine, psychostimulants, or combinations of these drugs, stratified by race and sex. Trend changes in AADR were analyzed using joinpoint regression models and expressed as average annual percent change (AAPC) during each period of the three waves of the opioid epidemic: 1999-2010 (wave 1), 2010-2013 (wave 2), and 2013-2018 (wave 3). Prevalence measures assessed the percent co-involvement of an investigated drug in the overall death from another drug.

RESULTS

Polysubstance mortality has shifted from a modest rise in death rates due to benzodiazepine-opioid overdoses among White persons (wave 1) to a substantial increase in death rates due to illicit drug combinations impacting both White and Black populations (wave 3). Concurrent cocaine-opioid use had the highest polysubstance mortality rates in 2018 among Black (5.28 per 100,000) and White (3.53 per 100,000) persons. The steepest increase in death rates during wave 3 was observed across all psychoactive drugs when combined with synthetic opioids in both racial groups. Since 2013, Black persons have died faster from cocaine-opioid and psychostimulant-opioid overdoses. Between 2013 and 2018, opioids were highly prevalent in cocaine-related deaths, increasing by 33% in White persons compared to 135% in Blacks. By 2018, opioids contributed to approximately half of psychostimulant and 85% of benzodiazepine fatal overdoses in both groups. The magnitude and type of drug combinations with the highest death rates differed by race and sex, with Black men exhibiting the highest overdose burden beginning in 2013.

CONCLUSIONS

The current drug crisis should be considered in the context of polysubstance use. Effective measures and policies are needed to curb synthetic opioid-involved deaths and address disparate mortality rates in Black communities.

Longitudinal polysubstance use patterns and non-fatal overdose: A repeated measures latent class analysis

BACKGROUND

Polysubstance use (PSU) is common among people who use opioids (PWUO) and has been associated with drug-related harms. We aimed to identify latent longitudinal PSU classes among a cohort of PWUO and characterize non-fatal overdose risks among different sub-classes over time.

METHODS

We used longitudinal data (2005-2018) from three ongoing prospective cohorts of people who use drugs in Vancouver, Canada. The primary outcome of interest was self-reported non-fatal overdose during the past six months. The primary exposure of interest was longitudinal PSU patterns among PWUO, obtained from repeated measures latent class analysis (RMLCA) of weekly substance use-related outcome indicators. Multivariable generalized estimating equations models were built to assess the association between latent PSU class membership and non-fatal overdose, adjusting for potential sociodemographic, behavioural, and structural confounders.

RESULTS

2627 PWUO were included in the analysis, and 1094 (41.6 %) had experienced at least one non-fatal overdose during the study period. RMLCA revealed five distinct latent longitudinal PSU classes, including low/infrequent use (Class 1; 30 %), primarily opioid and methamphetamine use (Class 2; 22 %), primarily cannabis use (Class 3; 15 %), primarily opioid and crack use (Class 4; 29 %), and frequent PSU (Class 5; 4 %). In comparison with Class 1 (low), membership in all latent PSU classes except Class 3 (cannabis) was associated with increased odds of non-fatal overdose: Class 2 (opioids + meth) vs. Class 1 (Adjusted odds ratios [aOR] = 2.20, 95 % confidence intervals [CI]: 1.51-3.22), Class 4 (opioids + crack) vs. Class 1 (aOR = 1.06, 95 % CI: 0.85-1.33), and Class 5 (frequent) vs. Class 1 (aOR = 2.39, 95 % CI: 1.92-2.97).

CONCLUSION

Our findings highlighted the heterogeneous characteristics of PWUO in terms of patterns of PSU and non-fatal overdose risk. The diverse nature of PWUO and the potential additive or multiplicative impact of using several substances on overdoses should be reflected across the substance use treatment continuum and care provision.

Racial and ethnic inequities in substance use treatment among women with opioid use disorder

Background: Research describes inequities in substance use treatment, but few studies focus specifically on racial and ethnic disparities in a range of aspects of substance use treatment among women with opioid use disorder (OUD).Objective: To examine whether substance use treatment (i.e. receipt, sources, barriers) differs by race and ethnicity among women with opioid use disorder (OUD) and to identify factors associated with treatment gap (i.e. needing treatment but not receiving it).Methods: We performed cross-sectional analyses using National Survey on Drug Use and Health 2015-2019 data, restricted to non-Hispanic Black, non-Hispanic White, and Hispanic women with past-year OUD (unweighted n = 1089). We estimated the prevalence of aspects of treatment among racial and ethnic groups, and used modified Poisson regression to estimate correlates of reported treatment gap.Results: Approximately 68% of White versus 87% of Black and 81% of Hispanic women with OUD had a treatment gap (p-value 0.0034). Commonly reported barriers to treatment included prioritization, affordability, and stigma. Older age was associated with lower prevalence of treatment gap among all women [prevalence ratio (PR) = 0.83, and 95% confidence interval (CI): 0.76, 0.92], while criminal legal involvement and healthcare coverage was associated with a lower prevalence of treatment gap among Hispanic and White women only (past year arrest: Hispanic women PR = 0.38, 95% CI: 0.17, 0.86; White women PR = 0.62, 95% CI: 0.47, 0.82).Conclusions: Receipt of treatment is low among women with OUD, especially Black and Hispanic women. Intersectional intervention approaches are needed to increase access and reduce inequities.

Associations between stimulant use and return to illicit opioid use following initiation onto medication for opioid use disorder

AIM

The aim of this study was to estimate how ongoing stimulant use affects return to illicit opioid use after initiation onto medication for opioid use disorder (MOUD).

DESIGN

This was a secondary analysis of pooled data from two clinical trials comparing buprenorphine (BUP-NX) and extended-release naltrexone (XR-NTX).

SETTING

Thirteen opioid treatment programs and HIV clinics across 10 states in the United States from 2014 to 2019 took part in this study.

PARTICIPANTS

A total of 528 participants who initiated MOUD as part of trial participation were included. Nearly half (49%) were between 30 and 49 years of age, 69% were male and 66% were non-Hispanic White.

MEASUREMENTS

The primary outcome was first self-reported day of non-prescribed opioid use following MOUD initiation, and the exposure of interest was daily stimulant use (methamphetamine, amphetamines or cocaine). Both were defined using time-line follow-back. Among participants reporting at least 1 day of illicit opioid use, we also examined relapse to ongoing use, defined as (1) 7 days of continuous opioid use or (2) 4 consecutive weeks with self-reported opioid use, one or more positive urine drug screens (UDS) for opioids or one or more missing UDS.

FINDINGS

Forty-seven per cent of participants reported stimulant use following MOUD initiation, 58% returned to illicit opioid use and 66% of those relapsed to ongoing use. Stimulant use was strongly associated with increased risk of misusing opioids after MOUD initiation when measured daily [adjusted hazard ratio (aHR) = 9.23, 95% confidence interval (CI) = 6.80-12.50, P < 0.001] and over a 7-day period (aHR = 1.27 for each additional day, CI = 1.18-1.37, P < 0.001). Using stimulants weekly or more often was associated with increased likelihood of relapse to ongoing opioid use compared with less than weekly or no stimulant use (adjusted odds ratio = 2.30, CI = 1.05-5.39, P = 0.044).

CONCLUSIONS

People initiated on medication for opioid use disorder who subsequently use stimulants appear to be more likely to return to and continue using non-prescribed opioids compared with those without stimulant use. The association appears to be stronger among patients who initiate buprenorphine compared with those who initiate extended-release naltrexone.

The Concordance of Electronic Health Record Diagnoses and Substance use Self-Reports Among Reproductive Aged Women Enrolled in a Community-Based Addiction Reduction Program

Substance use disorders among reproductive aged women are a major public health issue. There is little work investigating the validity and reliability of electronic health record (EHR) data for measuring substance use in this population. This study examined the concordance of self-reported substance use with clinical diagnoses of substance use, substance abuse and substance use disorder in EHR data. Reproductive age women enrolled in the Community-Based Addiction Reduction (CARE) program were interviewed by peer recovery coaches (PRC) at enrollment. That survey data was linked with EHR data (n = 102). Concordance between self-reported substance use and clinical diagnoses in the EHR was examined for opioids, cannabis/THC, and cocaine. Cohen's kappa, sensitivity, and specificity were calculated. The survey captured a higher number of women who use substances compared to the EHR. The concordance of self-report with EHR diagnosis varied by substance and was higher for opioids (17.6%) relative to cannabis/THC (8.8%), and cocaine (3.0%). Additionally, opioids had higher sensitivity (46.2%) and lower specificity (76.2%) relative to cannabis/THC and cocaine. Survey data collected by PRCs captured more substance use than EHRs, suggesting that EHRs underestimate substance use prevalence. The higher sensitivity and lower specificity of opioids was due to a larger number of women who had a diagnosis of opioid use in the EHR who did not self-report opioid use in the self-report survey relative to cannabis/THC and cocaine. Opioid self-report and diagnosis may be influenced by research setting, question wording, or receipt of medication for opioid use disorder.

Behavioral and Health Outcome Differences by Heroin or Methamphetamine Preference Among People in Rural US Communities Who Use Both Substances

Background

The United States' (US) opioid overdose epidemic has evolved into a combined stimulant/opioid epidemic, a pattern driven in part by mitigating opioid overdose risk, variable substance availability, and personal preferences. This study aimed to investigate the association between self-reported substance preference (heroin or methamphetamine) and behavioral/health outcomes among individuals who used both heroin and methamphetamine in the rural US.

Methods

The Rural Opioid Initiative is a consortium of 8 research cohorts from 10 states and 65 rural counties that recruited individuals reporting past 30-day injection of any substance or opioid substance use by any route from 1/2018 to 3/2020. Analyses were restricted to participants ⩾18 years, who self-reported either heroin or methamphetamine as their preferred substance and past 30-day use of both heroin and methamphetamine. We examined cross-sectional associations between preferred substance (heroin versus methamphetamine) and behavioral and health outcomes using random effects meta-analysis with adjusted regression models.

Results

Among 1239 participants, 61% (n = 752) reported heroin as their preferred substance. Adjusting for age, sex, and race/ethnicity, methamphetamine preference was associated with lower prevalence ratios for current naloxone possession (adjusted prevalence ratio [aPR] = 0.68; 95% Confidence Interval [95% CI] = 0.59-0.78; P-value ⩽ .001), of ever being told they had the hepatitis C virus (HCV; aPR = 0.72; 95% CI: 0.61-0.85; P-value ⩽ .001) and a personal history of overdose (aPR = 0.81; 95% CI = 0.73-0.90; P-value ⩽ .001).

Conclusion

In our study analyzing associations between preferred substance and various behavioral and health outcomes amongst people who use both heroin and methamphetamine, a majority of participants preferred heroin. Methamphetamine preference was associated with lower prevalence of naloxone possession, ever being told they had HCV, and prior history of an overdose. This study underscores the need for targeted harm reduction services for people who prefer methamphetamine in rural areas.

Opioid, methamphetamine, and polysubstance use: perinatal outcomes for the mother and infant

The escalation in opioid pain relief (OPR) medications, heroin and fentanyl, has led to an increased use during pregnancy and a public health crisis. Methamphetamine use in women of childbearing age has now eclipsed the use of cocaine and other stimulants globally. Recent reports have shown increases in methamphetamine are selective to opioid use, particularly in rural regions in the US. This report compares the extent of our knowledge of the perinatal outcomes of OPRs, heroin, fentanyl, two long-acting substances used in the treatment of opioid use disorders (buprenorphine and methadone), and methamphetamine. The methodological limitations of the current research are examined, and two important initiatives that will address these limitations are reviewed. Current knowledge of the perinatal effects of short-acting opioids, OPRs, heroin, and fentanyl, is scarce. Most of what we know about the perinatal effects of opioids comes from research on the long-acting opioid agonist drugs used in the treatment of OUDs, methadone and buprenorphine. Both have better perinatal outcomes for the mother and newborn than heroin, but the uptake of these opioid substitution programs is poor (<50%). Current research on perinatal outcomes of methamphetamine is limited to retrospective epidemiological studies, chart reviews, one study from a treatment center in Hawaii, and the US and NZ cross-cultural infant Development, Environment And Lifestyle IDEAL studies. Characteristics of pregnant individuals in both opioid and MA studies were associated with poor maternal health, higher rates of mental illness, trauma, and poverty. Infant outcomes that differed between opioid and MA exposure included variations in neurobehavior at birth which could complicate the diagnosis and treatment of neonatal opioid withdrawal (NOWs). Given the complexity of OUDs in pregnant individuals and the increasing co-use of these opioids with MA, large studies are needed. These studies need to address the many confounders to perinatal outcomes and employ neurodevelopmental markers at birth that can help predict long-term neurodevelopmental outcomes. Two US initiatives that can provide critical research and treatment answers to this public health crisis are the US Environmental influences on Child Health Outcomes (ECHO) program and the Medication for Opioid Use Disorder During Pregnancy Network (MAT-LINK).

Prenatal Substance Exposure and Neonatal Abstinence Syndrome: State Estimates from the 2016-2020 Transformed Medicaid Statistical Information System

INTRODUCTION

Estimating Neonatal Abstinence Syndrome (NAS) and prenatal substance exposure rates in Medicaid can help target program efforts to improve access to services.

METHODS

The data for this study was extracted from the 2016-2020 Transformed Medicaid Statistical Information System (T-MSIS) Analytic Files (TAF) Research Identifiable Files (RIF) and included infants born between January 1, 2016 and December 31, 2020 with a either a NAS diagnosis or prenatal substance exposure.

RESULTS

Between 2016 and 2020, the estimated national rate of NAS experienced a 18% decline, while the estimated national rate of prenatal substance exposure experienced a 3.6% increase. At the state level in 2020, the NAS rate ranged from 3.2 per 1000 births (Hawaii) to 68.0 per 1000 births (West Virginia). Between 2016 and 2020, 28 states experienced a decline in NAS births and 20 states had an increase in NAS rates. In 2020, the lowest prenatal substance exposure rate was observed in New Jersey (9.9 per 1000 births) and the highest in West Virginia (88.1 per 1000 births). Between 2016 and 2020, 38 states experienced an increase in the rate of prenatal substance exposure and 10 states experienced a decline.

DISCUSSION

Estimated rate of NAS has declined nationally, but rate of prenatal substance exposure has increased, with considerable state-level variation. The reported increase in prenatal substance exposure in the majority of US states (38) suggest that substances other than opioids are influencing this trend. Medicaid-led initiatives can be used to identify women with substance use and connect them to services.

Polysubstance use and post-discharge mortality risk among hospitalized patients with opioid use disorder

Polysubstance use is becoming increasingly common and presents several harms. This study aimed to examine the association of comorbid cocaine, alcohol (binge drinking), and sedative use with mortality among hospitalized patients with opioid use disorder (OUD). A subsample of adult medical/surgical hospital patients with OUD who were seen by a hospital addiction consultation service in Baltimore City and enrolled in a randomized trial of a patient navigation intervention were included in this study (N = 314; 45 % female; 48 % White; mean age = 44). Death certificate data from the Maryland Division of Vital Records was used, covering 3.3-5.5 years post-discharge. Multivariable proportional hazards Cox regression and competing risks regression were used to estimate all-cause mortality and overdose mortality, respectively, as a function of concurrent use of cocaine, alcohol (binge drinking), and non-prescribed sedatives at baseline. In the 30 days prior to hospital admission, 230 (73 %) participants used cocaine, 64 (20 %) binge drank, and 45 (14 %) used non-prescribed sedatives. Nearly one-third (N = 98; 31 %) died during the observation period. Drug overdose caused 53 % (N = 52) of deaths. Older age (HR = 1.03 [1.01,1.05]; P = 0.001), less than high school education (HR = 0.36 [0.24,0.54]; P < 0.001), and past 30-day sedative use (HR = 2.05 [1.20,3.50]; P = 0.008) were significantly associated with all-cause mortality. The risk of overdose mortality was 62 % lower (HR = 0.38 [0.22,0.66]; P = 0.001) for those who completed high school. No other characteristics were significantly associated with overdose mortality. The concurrent use of opioids and sedatives increases the post-discharge mortality risk among hospitalized patients with OUD. Interventions are needed to prevent mortality among this high-risk population.

Impact of an intervention to implement provision of opioid use disorder medication among patients with and without co-occurring substance use disorders

INTRODUCTION

Co-occurring substance use disorders (SUDs) are common among people with opioid use disorder (OUD) and known to hinder receipt of medications for OUD (MOUD). It is important to understand how MOUD care implemented outside of SUD specialty settings impacts access for patients with co-occurring SUDs. The Veterans Health Administration's (VA) Stepped Care for Opioid Use Disorder Train the Trainer (SCOUTT) initiative was implemented in primary care, mental health, and pain clinics in 18 VA facilities, and was found to increase MOUD receipt. This study assessed the SCOUTT initiative's impact among patients with and without co-occurring SUDs.

METHODS

This study used a controlled interrupted time series design. We extracted electronic health record data for patients with OUD with visits in SCOUTT intervention or matched comparison clinics during the post-implementation year (9/1/2018-8/31/2019). We examined the monthly proportion of patients who received MOUD in SCOUTT intervention or comparison clinics (primary care, mental health, and pain clinics), or in a VA SUD specialty clinic (where patients may have been referred), during the pre- and post-implementation years. Segmented logistic regression models estimated pre-post changes in outcomes (immediate level change from the final month of the pre-implementation period to the first month of the post-implementation period, change in trend/slope) in intervention vs. comparison facilities, adjusting for patient characteristics and pre-implementation trends. We stratified analyses by the presence of co-occurring SUDs.

RESULTS

Among patients without co-occurring SUDs, the pre-post trend/slope change in MOUD received in SCOUTT intervention or comparison clinics was greater in intervention vs. comparison facilities (adjusted odds ratio [aOR]: 1.06, 95% confidence interval [CI]: 1.02-1.10), and the immediate increase in MOUD received in SUD clinics was greater in intervention vs. comparison facilities (aOR: 1.12, 95% CI: 1.02-1.22). These changes did not significantly differ in intervention vs. comparison facilities among patients with co-occurring SUDs.

CONCLUSIONS

The SCOUTT initiative may have increased MOUD receipt primarily among patients without co-occurring SUDs. Focusing on increasing MOUD receipt for patients with co-occurring SUDs may improve the overall effectiveness of MOUD implementation efforts.

Examining Differences in Emotion Dysregulation Between Emerging Adult Alcohol-Only Users, Abstainers, and Simultaneous Users

Objective

Simultaneous use of alcohol and cannabis is associated with more negative consequences than use of either substance alone. Research suggests that emotion dysregulation is linked to alcohol, cannabis, and polysubstance use. However, no previous research has examined whether emotion dysregulation scores differ among individuals without past month substance use (abstainers), individuals who report past-month alcohol use only (no past month cannabis or simultaneous use; alcohol-only users), and individuals who engage in past-month simultaneous alcohol and cannabis use (simultaneous users). Our aim was to examine differences in overall levels of emotion dysregulation and emotion dysregulation subscales between these groups.

Methods

The sample included 468 college students. Participants completed an online survey assessing demographics, emotion dysregulation, average number of drinks per week, days of monthly cannabis use, and simultaneous use of alcohol and cannabis.

Results

A one-way ANOVA showed significant differences in emotion dysregulation between alcohol-only users, abstainers, and simultaneous users. A Bonferroni post hoc analysis revealed significant differences in emotion dysregulation for simultaneous users (p = .004) compared to alcohol-only users and abstainers. A series of ANOVAs were run to examine emotion dysregulation subscale scores and significant differences were found for impulse control difficulties (p = .003) and limited access to emotion regulation strategies (p = .005) for simultaneous users compared to alcohol-only users and abstainers, and for non-acceptance of emotional responses (p = .018) for simultaneous users compared to and alcohol-only users.

Conclusion

These findings indicate that simultaneous users have higher levels of emotion dysregulation, higher levels of impulse control difficulties, greater non-acceptance of emotions, and greater lack of access to emotion regulation strategies compared to abstainers and alcohol-only users.

Implementing harm reduction kits in an office-based addiction treatment program

BACKGROUND

The rising rates of drug use-related complications call for a paradigm shift in the care for people who use drugs. While addiction treatment and harm reduction have historically been siloed in the US, co-location of these services in office-based addiction treatment (OBAT) settings offers a more realistic and patient-centered approach. We describe a quality improvement program on integrating harm reduction kits into an urban OBAT clinic.

METHODS

After engaging appropriate stakeholders and delivering clinician and staff trainings on safer use best practices, we developed a clinical workflow for universal offering and distribution of pre-packaged kits coupled with patient-facing educational handouts. We assessed: (1) kit uptake with kit number and types distributed; and (2) implementation outcomes of feasibility, acceptability, appropriateness, and patient perceptions.

RESULTS

One-month post-implementation, 28% (40/141) of completed in-person visits had at least one kit request, and a total of 121 kits were distributed. Staff and clinicians found the program to be highly feasible, acceptable, and appropriate, and patient perceptions were positive.

CONCLUSIONS

Incorporating kits in OBAT settings is an important step toward increasing patient access and utilization of life-saving services. Our program uncovered a significant unmet need among our patients, suggesting that kit integration within addiction treatment can improve the standard of care for people who use drugs.

Postmortem toxicology findings from the Camden Opioid Research Initiative

The United States continues to be impacted by decades of an opioid misuse epidemic, worsened by the COVID-19 pandemic and by the growing prevalence of highly potent synthetic opioids (HPSO) such as fentanyl. In instances of a toxicity event, first-response administration of reversal medications such as naloxone can be insufficient to fully counteract the effects of HPSO, particularly when there is co-occurring substance use. In an effort to characterize and study this multi-faceted problem, the Camden Opioid Research Initiative (CORI) has been formed. The CORI study has collected and analyzed post-mortem toxicology data from 42 cases of decedents who expired from opioid-related toxicity in the South New Jersey region to characterize substance use profiles. Co-occurring substance use, whether by intent or through possible contamination of the illicit opioid supply, is pervasive among deaths due to opioid toxicity, and evidence of medication-assisted treatment is scarce. Nearly all (98%) of the toxicology cases show the presence of the HPSO, fentanyl, and very few (7%) results detected evidence of medication-assisted treatment for opioid use disorder, such as buprenorphine or methadone, at the time of death. The opioid toxicity reversal drug, naloxone, was detected in 19% of cases, but 100% of cases expressed one or more stimulants, and sedatives including xylazine were detected in 48% of cases. These results showing complex substance use profiles indicate that efforts at mitigating the opioid misuse epidemic must address the complications presented by co-occurring stimulant and other substance use, and reduce barriers to and stigmas of seeking effective medication-assisted treatments.

Associations between short-term ambient temperature exposure and emergency department visits for amphetamine, cocaine, and opioid use in California from 2005 to 2019

Substance use disorder is a growing public health challenge in the United States. People who use drugs may be more vulnerable to ambient heat due to the effects of drugs on thermoregulation and their risk environment. There have been limited population-based studies of ambient temperature and drug-related morbidity. We examined short-term associations between daily ambient temperature and emergency department (ED) visits for use or overdose of amphetamine, cocaine and opioids in California during the period 2005 to 2019. Daily ZIP code-level maximum, mean, and minimum temperature exposures were derived from 1-km data Daymet products. A time-stratified case-crossover design was used to estimate cumulative non-linear associations of daily temperature for lag days 0 to 3. Stratified analyses by patient sex, race, and ethnicity were also conducted. The study included over 3.4 million drug-related ED visits. We found positive associations between daily temperature and ED visits for all outcomes examined. An increase in daily mean temperature from the 50th to the 95th percentile was associated with ED visits for amphetamine use (OR = 1.072, 95% CI: 1.058, 1.086), cocaine use (OR = 1.044, 95% CI: 1.021, 1.068 and opioid use (OR = 1.041, 95% CI: 1.025, 1.057). Stronger positive associations were also observed for overdose: amphetamine overdose (OR = 1.150, 95% CI: 1.085, 1.218), cocaine overdose (OR = 1.159, 95% CI: 1.053, 1.276), and opioid overdose (OR = 1.079, 95% CI: 1.054, 1.106). In summary, people who use stimulants and opioids may be a subpopulation sensitive to short-term higher ambient temperature. Mitigating heat exposure can be considered in harm reduction strategies in response to the substance use epidemic and global climate change.

Educational Attainment and US Drug Overdose Deaths

Importance

Educational attainment in the US is associated with life expectancy. As the opioid crisis worsens, it is critical to understand how overdose death rate trends evolve across education groups.

Objective

To investigate the association between educational attainment and overdose death rates, with emphasis on trends during the COVID-19 pandemic.

Design, Setting, and Participants

This cross-sectional study used National Vital Statistics System Mortality Multiple Cause-of-Death data describing overdose death rates in the US by educational attainment from January 1, 2000, to December 31, 2021, with a focus on 2018 to 2021. Overdose deaths were aggregated by year and educational level for decedents aged 25 years or older.

Exposure

Educational attainment, categorized as no high school (HS) diploma, HS diploma (or General Educational Development) but no college, some college but no bachelor's degree, and bachelor's degree or more.

Main Outcomes and Measures

The main outcomes were rates of all overdose deaths, overdose deaths involving opioids, and overdose deaths involving synthetic opioids.

Results

Of 912 057 overdose deaths with education information from 2000 to 2021 (mean [SD] age at death, 44.9 [12.3] years; 64.1% male), there were 625 400 deaths (68.6%) among individuals with no college education and 286 657 deaths (31.4%) among those with at least some college. The overdose death rate was 19.9 per 100 000 population. From 2018 to 2021, there were 301 557 overdose deaths, including 58 319 (19.3%) among individuals without an HS diploma, 153 603 (50.9%) among people with an HS diploma, 64 682 (21.4%) among individuals with some college, and 24 953 (8.3%) among individuals with a bachelor's degree. There were 3324 overdose deaths (1.1%) among American Indian or Alaska Native individuals, 2968 (1.0%) among Asian American or Pacific Islander individuals, 49 152 (16.3%) among Black individuals, 31 703 (10.5%) among Hispanic individuals, 211 359 (70.1%) among White individuals, and 3051 (1.0%) among multiracial individuals. From 2018 to 2021, the overdose death rate was 33.4 per 100 000 population, the opioid-related overdose death rate was 24.2 per 100 000 population, and the synthetic opioid overdose death rate was 19.1 per 100 000 population. From 2018 to 2021, the overdose death rate for those without a HS diploma increased by 35.4 per 100 000 population compared with 1.5 per 100 000 population for those with a bachelor's degree. This differential growth was primarily due to increased rates of death involving synthetic opioids.

Conclusions and Relevance

In this cross-sectional study, lower educational attainment was found to be associated with higher growth in overdose deaths. As the opioid crisis has transitioned to fentanyl and polysubstance use, overdose deaths have become more prevalent in groups with lower socioeconomic status, potentially exacerbating existing life-expectancy disparities.

Associations of hepatitis C virus (HCV) antibody positivity with opioid, stimulant, and polysubstance injection among people who inject drugs (PWID) in rural U.S. communities

BACKGROUND

People who inject drugs (PWID) in the rural U.S. often inject stimulants, alone or with opioids. The impact of these substance use patterns may influence HCV risk behaviors. This analysis examines the associations of HCV antibody positivity with injecting only opioids, only stimulants (methamphetamine/cocaine), and opioids and stimulants together among rural PWID.

METHODS

The Rural Opioid Initiative (ROI) consists of eight research sites that enrolled people who use drugs in rural communities in ten U.S. states from 2018 to 2020. This cross-sectional analysis included adult participants who resided in a study area and injected any drug in the past 30 days. The primary outcome was HCV antibody positivity. The exposure of interest was injection drug use classified as only opioids, only stimulants, separate injections of opioids and stimulants, and same-syringe injection of both in the past 30 days. We used multivariable log-binomial regression with generalized linear mixed models to generate prevalence ratios (P.R.) adjusted for demographics, injection history, health insurance, and substance use treatment.

RESULTS

Among 3,084 participants enrolled in the ROI, 1,982 met inclusion criteria. Most participants injected opioids and stimulants in the same syringe (34%) or separately (21%), followed by injecting only stimulants (26%), and injecting only opioids (19%). Half (51%) were HCV antibody positive. Compared to people who injected only stimulants, HCV antibody positivity was more prevalent among people who injected opioids alone (aPR=1.62, 95% CI:(1.29-2.03)), injected both opioids and stimulants separately (aPR=1.61, 95% CI:(1.32-1.95)), and in the same syringe (aPR=1.54, 95% CI:(1.28-1.85)).

CONCLUSION

HCV antibody positivity, indicating prior exposure, was highest among those who had recently injected opioids, alone or with stimulants. Additional nucleic acid testing is necessary to confirm active infection. More research is needed to determine the underlying causes of HCV antibody positivity by injection use.

Treatment Initiation, Substance Use Trajectories, and the Social Determinants of Health in Persons Living With HIV Seeking Medication for Opioid Use Disorder

BACKGROUND

People living with HIV and opioid use disorder (OUD) are disproportionally affected by adverse socio-structural exposures negatively affecting health, which have shown inconsistent associations with uptake of medications for OUD (MOUD). This study aimed to determine whether social determinants of health (SDOH) were associated with MOUD uptake and trajectories of substance use in a clinical trial of people seeking treatment.

METHODS

Data are from a 2018 to 2019 randomized trial comparing the effectiveness of different MOUD to achieve viral suppression among people living with HIV and OUD. SDOH were defined by variables mapping to Healthy People 2030 domains: education (Education Access and Quality), income (Economic Stability), homelessness (Neighborhood and Built Environment), criminal justice involvement (Social and Community Context), and recent SUD care (Health Care Access and Quality). Associations between SDOH and MOUD initiation were assessed with Cox proportional hazards models, and SDOH and substance use over time with generalized estimating equation models.

RESULTS

Participants (N = 114) averaged 47 years old, 63% were male, 56% were Black, and 12% Hispanic. Participants reported an average of 2.3 out of 5 positive SDOH indicators (SD = 1.2). Stable housing was the most commonly reported SDOH (61%), followed by no recent criminal justice involvement (59%), having a high-school level education or greater (56%), income stability (45%), and recent SUD care (13%). Each additional favorable SDOH was associated with a 25% increase in the likelihood of MOUD initiation during the study period [adjusted HR = 1.25, 95% CI = (1.01, 1.55), P = .044]. Positive SDOH were also associated with a decrease in the odds of baseline opioid use and a greater reduction in opioid use during subsequent weeks of the study (P < .001 for a joint test of baseline and slope differences).

CONCLUSIONS

Positive social determinants of health, in aggregate, may increase the likelihood of MOUD treatment initiation among people living with HIV and OUD.

The interaction of genetic sex and prenatal alcohol exposure on health across the lifespan

Prenatal alcohol exposure (PAE) can reprogram the development of cells and tissues, resulting in a spectrum of physical and neurobehavioral teratology. PAE immediately impacts fetal growth, but its effects carry forward post-parturition, into adolescence and adulthood, and can result in a cluster of disabilities, collectively termed Fetal Alcohol Spectrum Disorders. Emerging preclinical and clinical research investigating neurological and behavioral outcomes in exposed offspring point to genetic sex as an important modifier of the effects of PAE. In this review, we discuss the literature on sex differences following PAE, with studies spanning the fetal period through adulthood, and highlight gaps in research where sex differences are likely, but currently under-investigated. Understanding how sex and PAE interact to affect offspring health outcomes across the lifespan is critical for identifying the full complement of PAE-associated secondary conditions, and for refining targeted interventions to improve the quality of life for individuals with PAE.

Novel RNA-Seq Signatures Post-Methamphetamine and Oxycodone Use in a Model of HIV-Associated Neurocognitive Disorders

In the 21st century, the effects of HIV-associated neurocognitive disorders (HAND) have been significantly reduced in individuals due to the development of antiretroviral therapies (ARTs). However, the growing epidemic of polysubstance use (PSU) has led to concern for the effects of PSU on HIV-seropositive individuals. To effectively treat individuals affected by HAND, it is critical to understand the biological mechanisms affected by PSU, including the identification of novel markers. To fill this important knowledge gap, we used an in vivo HIV-1 Transgenic (HIV-1 Tg) animal model to investigate the effects of the combined use of chronic methamphetamine (METH) and oxycodone (oxy). A RNA-Seq analysis on the striatum-a brain region that is primarily targeted by both HIV and drugs of abuse-identified key differentially expressed markers post-METH and oxy exposure. Furthermore, ClueGO analysis and Ingenuity Pathway Analysis (IPA) revealed crucial molecular and biological functions associated with ATP-activated adenosine receptors, neuropeptide hormone activity, and the oxytocin signaling pathway to be altered between the different treatment groups. The current study further reveals the harmful effects of chronic PSU and HIV infection that can subsequently impact neurological outcomes in polysubstance users with HAND.

Understanding polysubstance use at the daily and event levels: protocol for a mixed-methods qualitative and ecological momentary assessment study in a community-based sample of people who use illicit drugs in Oakland, California, USA

INTRODUCTION

Polysubstance use is extremely common among people who use illicit opioids in the USA. It is associated with poor substance use treatment outcomes, infectious disease risk and alarming rates of drug overdose. Nearly all extant literature examines polysubstance use over broad time frames, such as 30 days or 6 months. However, both substance use and overdose risk are episodic. To build a stronger understanding of polysubstance use and overdose risk, we need to expand the knowledge base to include daily-level and event-level data that examine how substances are used together, in which combinations and in which contexts. The study described in this protocol will use qualitative and ecological momentary assessment (EMA) methods to examine polysubstance use and overdose risk on a daily and event level.

METHODS AND ANALYSIS

This is a mixed-methods observational study with three phases. The first phase is formative, consisting of qualitative interviews with people who use multiple substances (N=20), to inform the development of items for the EMA component. The second phase is EMA data collection with people who use multiple substances (N=120), three times daily for 28 days. The third phase consists of mixed-methods inquiries with a subset of participants (N=20), using participant-level EMA data and qualitative techniques to build a nuanced understanding of the motivations and contexts of polysubstance use in everyday life. Analytical induction methods will be used to interpret qualitative data. Hierarchical linear modelling methods will be used to analyse EMA data.

ETHICS AND DISSEMINATION

This research has been reviewed and approved by the Institutional Review Board at RTI International (#MOD00001782 for EMA procedures and #MOD00001241 for qualitative procedures). Participants engage in an informed consent procedure for each component of the study. Data will be managed and shared per the National Institutes of Health extramural data sharing policy.

Longitudinal latent polysubstance use patterns among a cohort of people who use opioids in Vancouver, Canada

INTRODUCTION

Polysubstance use (PSU) practices are increasing among people who use opioids (PWUO). However, several aspects of longitudinal PSU patterns among PWUO remain understudied. This study aims to identify person-centred longitudinal patterns of PSU among a cohort of PWUO.

METHODS

Using longitudinal data (2005-2018) from three prospective cohort studies including people who use drugs in Vancouver, Canada, we used repeated measures latent class analysis to identify different PSU classes among PWUO. Multivariable generalised estimating equations models weighted by the respective posterior membership probabilities were applied to identify covariates of membership in different PSU classes over time.

RESULTS

Overall, 2627 PWUO (median age at baseline: 36 [quartile 1-3: 25-45]) were included between 2005 and 2018. We found five distinct PSU patterns, including low/infrequent probability of regular substance use (Class 1; 30%), primarily opioid and methamphetamine use (Class 2; 22%), primarily cannabis use (Class 3; 15%), primarily opioid and crack use (Class 4; 29%) and frequent PSU (Class 5; 4%). Membership in Class 2, 4 and 5 was positively associated with several behavioural and socio-structural adversities.

DISCUSSION AND CONCLUSIONS

Findings of this longitudinal study suggest PSU is the norm among PWUO and highlights the heterogeneous characteristics of PWUO. The diversities within the population of PWUO need to be recognised in addiction care and treatment as well as optimising resource allocation in the response to the overdose crisis.

Methamphetamine use and utilization of medications for opioid use disorder among rural people who use drugs

BACKGROUND

Methamphetamine use is common among persons with opioid use disorder. This study evaluated associations between methamphetamine use and treatment with agonist medications for opioid use disorder (MOUD, specifically buprenorphine, and/or methadone) in U.S. rural communities.

METHODS

The Rural Opioid Initiative (ROI) is a consortium spanning 10 states and 65 rural counties that included persons who reported past 30-day use of opioids and/or injection drug use between 1/2018 and 3/2020. Analyses were restricted to participants who had ever used opioids and had data on past 30-day methamphetamine use. Multivariable models examined the relationship between methamphetamine use and utilization of agonist MOUD.

RESULTS

Among 2899 participants, 2179 (75.2%) also reported recent methamphetamine use. Persons with methamphetamine use compared to those without were younger, more likely to have injected drugs, be unhoused, criminal justice involved, and less likely to have health insurance. Adjusted for age, sex, race, and study site, recent methamphetamine use was associated with lower relative odds of past 30-day methadone treatment (aOR=0.66; 95% CI: 0.45-0.99) and fewer methadone treatment days (aIRR=0.76; 0.57-0.99), but not past 30-day buprenorphine receipt (aOR=0.90; 0.67-1.20), buprenorphine treatment days in past 6 months: aIRR=0.88; 0.69-1.12) or perceived inability to access buprenorphine (aOR=1.12; 0.87-1.44) or methadone (aOR=1.06; 0.76-1.48).

CONCLUSION

Methamphetamine use is common among persons who use opioids in rural U.S. areas and negatively associated with current treatment and retention on methadone but not buprenorphine. Future studies should examine reasons for this disparity and reduce barriers to methadone for persons who use opioids and methamphetamine.

Rural communities face more than an opioid crisis: Reimagining funding assistance to address polysubstance use, associated health problems, and limited rural service capacity

PURPOSE

Rural communities in the United States face unique challenges related to the opioid epidemic. This paper explores the substances and substance-related health problems that pose the greatest concern to rural communities that received funding to address the opioid epidemic and examines their reported capacity to address these challenges.

METHODS

This paper analyzed data collected as part of quarterly progress reporting from multisector consortiums across 2 cohorts of grantees funded to reduce the morbidity and mortality of opioids. Consortium project directors ranked the top 3 issues in their community in each of the following categories: (1) drugs of concern; (2) drugs with the least capacity to address; (3) related problem areas of concern (eg, neonatal abstinence syndrome [NAS]); and (4) related problem areas with the least capacity to address.

FINDINGS

Methamphetamines, fentanyl, and alcohol were the substances rated as most problematic in rural communities funded to address the opioid epidemic across all reporting periods. Over 40% of respondents ranked methamphetamine as a top concern and the substance they had the least capacity to address. This was nearly double the percentage of the next highest-ranked substance (fentanyl). Overdoses, NAS, and viral hepatitis constituted the top-ranking related concerns, with limited capacity to address them.

CONCLUSIONS

Multiple drug and concomitant problems coalesced on rural communities during the opioid epidemic. Funding communities to address substance use disorders and related problems of concern, rather than targeting funding toward a specific type of drug, may result in better health outcomes throughout the entire community.