A systematic review and meta-analysis of medications for stimulant use disorders in patients with co-occurring opioid use disorders

Sociodemographic and patient reported outcomes by racial and ethnicity status among participants in a randomized controlled trial for methamphetamine use disorder

Background

There has been a significant increase in methamphetamine use and methamphetamine use disorder (Meth UD) in the United States, with evolving racial and ethnic differences.

Objectives

This secondary analysis explored racial and ethnic differences in baseline sociodemographic and clinical characteristics as well as treatment effects on a measure of substance use recovery, depression symptoms, and methamphetamine craving among participants in a pharmacotherapy trial for Meth UD.

Methods

The ADAPT-2 trial (ClinicalTrials.gov number, NCT03078075; N=403; 69% male) was a multisite, 12-week randomized, double-blind, trial that employed a two-stage sequential parallel design to evaluate the efficacy of combination naltrexone (NTX) and oral bupropion (BUP) vs. placebo for Meth UD. Treatment effect was calculated as the weighted mean change in outcomes in the NTX-BUP minus placebo group across the two stages of treatment.

Results

Of the 403 participants in the ADAPT-2 trial, the majority (65%) reported non-Hispanic White, while 14%, 11% and 10% reported Hispanic, non-Hispanic Black, and non-Hispanic other racial and ethnic categories respectively. At baseline non-Hispanic Black participants reported less severe indicators of methamphetamine use than non-Hispanic White. Treatment effects for recovery, depression symptoms and methamphetamine cravings did not significantly differ by race and ethnicity.

Conclusions

Although we found racial and ethnic differences at baseline, our findings did not show racial and ethnic differences in treatment effects of NTX-BUP on recovery, depression symptoms and methamphetamine cravings. However, our findings also highlight the need to expand representation of racial and ethnic minority groups in future trials.

The ASAM/AAAP Clinical Practice Guideline on the Management of Stimulant Use Disorder

The American Society of Addiction Medicine/American Academy of Addiction Psychiatry (ASAM/AAAP) Clinical Practice Guideline on the Management of Stimulant Use Disorder provides guidance on evidence-based strategies for the treatment of stimulant use disorders (StUDs), stimulant intoxication, and stimulant withdrawal, as well as secondary and tertiary prevention of harms associated with stimulant use. The Clinical Guideline Committee (CGC) comprised experts from ASAM and AAAP representing a range of clinical settings and patient populations. The guideline was developed following modified GRADE methodology. The process included a systematic literature review as well as several targeted supplemental searches. The CGC utilized Evidence to Decision tables to review available evidence and rate the strength of each recommendation. The clinical practice guideline was revised based on external stakeholder review. Key takeaways included: Contingency management represents the current standard of care for treatment of StUDs; Pharmacotherapies may be utilized off-label to treat StUDs; Acute stimulant intoxication can result in life-threatening complications that should be addressed in an appropriate level of care; Secondary and tertiary prevention strategies should be used to reduce harms related to risky stimulant use.

The Association Between Self-Reported Anxiety and Retention in Opioid Agonist Therapy: Findings From a Canadian Pragmatic Trial

BACKGROUND

Prescription-type opioid use disorder (POUD) is often accompanied by comorbid anxiety, yet the impact of anxiety on retention in opioid agonist therapy (OAT) is unclear. Therefore, this study investigated whether baseline anxiety severity affects retention in OAT and whether this effect differs by OAT type (methadone maintenance therapy (MMT) vs. buprenorphine/naloxone (BNX)).

METHODS

This secondary analysis used data from a pan-Canadian randomized trial comparing flexible take-home dosing BNX and standard supervised MMT for 24 weeks. The study included 268 adults with POUD. Baseline anxiety was assessed using the Beck Anxiety Inventory (BAI), with BAI ≥ 16 indicating moderate-to-severe anxiety. The primary outcomes were retention in assigned and any OAT at week 24. In addition, the impact of anxiety severity on retention was examined, and assigned OAT was considered an effect modifier.

RESULTS

Of the participants, 176 (65%) reported moderate-to-severe baseline anxiety. In adjusted analyses, there was no significant difference in retention between those with BAI ≥ 16 and those with BAI < 16 assigned (29% vs. 28%; odds ratio (OR) = 2.03, 95% confidence interval (CI) = 0.94-4.40; P = 0.07) or any OAT (35% vs. 34%; OR = 1.57, 95% CI = 0.77-3.21; P = 0.21). In addition, there was no significant effect modification by OAT type for retention in assigned (P = 0.41) or any OAT (P = 0.71). In adjusted analyses, greater retention in treatment was associated with BNX (vs. MMT), male gender identity (vs. female, transgender, or other), enrolment in the Quebec study site (vs. other sites), and absence of a positive urine drug screen for stimulants at baseline.

CONCLUSIONS

Baseline anxiety severity did not significantly impact retention in OAT for adults with POUD, and there was no significant effect modification by OAT type. However, the overall retention rates were low, highlighting the need to develop new strategies to minimize the risk of attrition from treatment.

CLINICAL TRIAL REGISTRATION

This study was registered in ClinicalTrials.gov (NCT03033732).

Psychosocial interventions for stimulant use disorder

BACKGROUND

Stimulant use disorder is a continuously growing medical and social burden without approved medications available for its treatment. Psychosocial interventions could be a valid approach to help people reduce or cease stimulant consumption. This is an update of a Cochrane review first published in 2016.

OBJECTIVES

To assess the efficacy and safety of psychosocial interventions for stimulant use disorder in adults.

SEARCH METHODS

We searched the Cochrane Drugs and Alcohol Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, three other databases, and two trials registers in September 2023. All searches included non-English language literature. We handsearched the references of topic-related systematic reviews and the included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing any psychosocial intervention with no intervention, treatment as usual (TAU), or a different intervention in adults with stimulant use disorder.

DATA COLLECTION AND ANALYSIS

We used the standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included a total of 64 RCTs (8241 participants). Seventy-three percent of studies included participants with cocaine or crack cocaine use disorder; 3.1% included participants with amphetamine use disorder; 10.9% included participants with methamphetamine use disorder; and 12.5% included participants with any stimulant use disorder. In 18 studies, all participants were in methadone maintenance treatment. In our primary comparison of any psychosocial treatment to no intervention, we included studies which compared a psychosocial intervention plus TAU to TAU alone. In this comparison, 12 studies evaluated cognitive behavioural therapy (CBT), 27 contingency management, three motivational interviewing, one study looked at psychodynamic therapy, and one study evaluated CBT plus contingency management. We also compared any psychosocial intervention to TAU. In this comparison, seven studies evaluated CBT, two contingency management, two motivational interviewing, and one evaluated a combination of CBT plus motivational interviewing. Seven studies compared contingency management reinforcement related to abstinence versus contingency management not related to abstinence. Finally, seven studies compared two different psychosocial approaches. We judged 65.6% of the studies to be at low risk of bias for random sequence generation and 19% at low risk for allocation concealment. Blinding of personnel and participants was not possible for the type of intervention, so we judged all the studies to be at high risk of performance bias for subjective outcomes but at low risk for objective outcomes. We judged 22% of the studies to be at low risk of detection bias for subjective outcomes. We judged most of the studies (69%) to be at low risk of attrition bias. When compared to no intervention, we found that psychosocial treatments: reduce the dropout rate (risk ratio (RR) 0.82, 95% confidence interval (CI) 0.74 to 0.91; 30 studies, 4078 participants; high-certainty evidence); make little to no difference to point abstinence at the end of treatment (RR 1.15, 95% CI 0.94 to 1.41; 12 studies, 1293 participants; high-certainty evidence); make little to no difference to point abstinence at the longest follow-up (RR 1.22, 95% CI 0.91 to 1.62; 9 studies, 1187 participants; high-certainty evidence); probably increase continuous abstinence at the end of treatment (RR 1.89, 95% CI 1.20 to 2.97; 12 studies, 1770 participants; moderate-certainty evidence); may make little to no difference in continuous abstinence at the longest follow-up (RR 1.14, 95% CI 0.89 to 1.46; 4 studies, 295 participants; low-certainty evidence); reduce the frequency of drug intake at the end of treatment (standardised mean difference (SMD) -0.35, 95% CI -0.50 to -0.19; 10 studies, 1215 participants; high-certainty evidence); and increase the longest period of abstinence (SMD 0.54, 95% CI 0.41 to 0.68; 17 studies, 2118 participants; high-certainty evidence). When compared to TAU, we found that psychosocial treatments reduce the dropout rate (RR 0.79, 95% CI 0.65 to 0.97; 9 studies, 735 participants; high-certainty evidence) and may make little to no difference in point abstinence at the end of treatment (RR 1.67, 95% CI 0.64 to 4.31; 1 study, 128 participants; low-certainty evidence). We are uncertain whether they make any difference in point abstinence at the longest follow-up (RR 1.31, 95% CI 0.86 to 1.99; 2 studies, 124 participants; very low-certainty evidence). Compared to TAU, psychosocial treatments may make little to no difference in continuous abstinence at the end of treatment (RR 1.18, 95% CI 0.92 to 1.53; 1 study, 128 participants; low-certainty evidence); probably make little to no difference in the frequency of drug intake at the end of treatment (SMD -1.17, 95% CI -2.81 to 0.47, 4 studies, 479 participants, moderate-certainty evidence); and may make little to no difference in the longest period of abstinence (SMD -0.16, 95% CI -0.54 to 0.21; 1 study, 110 participants; low-certainty evidence). None of the studies for this comparison assessed continuous abstinence at the longest follow-up. Only five studies reported harms related to psychosocial interventions; four of them stated that no adverse events occurred.

AUTHORS' CONCLUSIONS

This review's findings indicate that psychosocial treatments can help people with stimulant use disorder by reducing dropout rates. This conclusion is based on high-certainty evidence from comparisons of psychosocial interventions with both no treatment and TAU. This is an important finding because many people with stimulant use disorders leave treatment prematurely. Stimulant use disorders are chronic, lifelong, relapsing mental disorders, which require substantial therapeutic efforts to achieve abstinence. For those who are not yet able to achieve complete abstinence, retention in treatment may help to reduce the risks associated with stimulant use. In addition, psychosocial interventions reduce stimulant use compared to no treatment, but they may make little to no difference to stimulant use when compared to TAU. The most studied and promising psychosocial approach is contingency management. Relatively few studies explored the other approaches, so we cannot rule out the possibility that the results were imprecise due to small sample sizes.

Navigating the Complex Intersection of Substance Use and Psychiatric Disorders: A Comprehensive Review

The co-occurrence of substance use disorders (SUDs) and psychiatric conditions, often referred to as comorbidity or concurrent disorders, presents intricate challenges in both diagnosis and treatment. This comprehensive narrative review aims to synthesize and critically evaluate the existing evidence surrounding the management of individuals with comorbid SUDs and psychiatric disorders. Comorbidity in these domains carries profound implications for clinical practice, research, and policymaking, emphasizing the need for a holistic understanding of the intricate dynamics that arise when these conditions coexist. This review explores recent research findings, evidence-based guidelines, and emerging trends within the field, offering valuable insights for clinicians, researchers, and policymakers seeking to navigate the complex terrain of comorbidity in substance use and psychiatric disorders.

Linkage facilitation services for opioid use disorder: Taxonomy of facilitation practitioners, goals, and activities

INTRODUCTION

This article proposes a taxonomy of linkage facilitation services used to help persons with opioid use disorder access treatment and recovery resources. Linkage facilitation may be especially valuable for persons receiving medication for opioid use disorder (MOUD) given the considerable barriers to treatment access and initiation that have been identified. The science of linkage facilitation currently lacks both consistent communication about linkage facilitation practices and a conceptual framework for guiding research.

METHODS

To address this gap, this article presents a taxonomy derived from expert consensus that organizes the array of practitioners, goals, and activities associated with linkage services for OUD and related needs. Expert panelists first independently reviewed research reports and policy guidelines summarizing the science and practice of linkage facilitation for substance use disorders generally and OUD specifically, then met several times to vet the conceptual scheme and content of the taxonomy until they reached a final consensus.

RESULTS

The derived taxonomy contains eight domains: facilitator identity, facilitator lived experience, linkage client, facilitator-client relationship, linkage activity, linkage method, linkage connectivity, and linkage goal. For each domain, the article defines basic domain categories, highlights research and practice themes in substance use and OUD care, and introduces innovations in linkage facilitation being tested in one of two NIDA-funded research networks: Justice Community Opioid Innovation Network (JCOIN) or Consortium on Addiction Recovery Science (CoARS).

CONCLUSIONS

To accelerate consistent application of this taxonomy to diverse research and practice settings, the article concludes by naming several considerations for linkage facilitation workforce training and implementation.

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.

Bupropion for treatment of amphetamine-type stimulant use disorder: A systematic review and meta-analysis of placebo-controlled randomized clinical trials

BACKGROUND

This meta-analysis (PROSPERO-ID: CRD42022362962), pooled effect estimates of outcomes, from placebo-controlled randomized clinical trials (RCTs) examining bupropion efficacy and safety for amphetamine-type stimulant use disorder (ATSUD) treatment.

METHOD

Electronic databases were searched for records published to October 31st, 2022, including MEDLINE, CINAHL, PsycINFO, EBM Reviews, EMBASE, PubMed, Web of Science, trial registries. Inclusion criteria were RCTs comparing bupropion to placebo in ATSUD. Cochrane RoB2 tool and GRADE evidence certainty assessment were employed. Outcomes included amphetamine-type stimulant (ATS) use by urinalysis, retention in treatment, treatment adherence, ATS craving, addiction severity, depressive symptom severity, drop-out following adverse events (AEs), and serious AEs. Random-effect meta-analysis was conducted presenting standardized mean difference (SMD), risk ratio (RR), and risk difference (RD).

RESULTS

Eight RCTs (total N=1239 participants) were included. Bupropion compared to placebo was associated with reduced ATS use (RR: 0.90; 95% CI: 0.84, 0.96), end-of-treatment ATS craving (SMD: -0.38; 95%CI: -0.63, -0.13), and adherence (RR: 0.91; 95%CI: 0.84, 0.99). Subgroup analysis showed greater reduction in ATS use with longer trial duration (12 weeks) (RR: 0.85; 95%CI: 0.78, 0.93) and greater reduction in end-of-treatment ATS craving in studies with mixed ATS use frequency (SMD: -0.46; 95%CI: -0.70, -0.22) and male-only samples (SMD: -1.26; 95%CI: -1.87, -0.65).

CONCLUSION

Bupropion showed a significant modest reduction in ATS use and ATS craving (both rated as very low-quality evidence), larger in males (craving), and with longer treatment (ATS use). These results may inform future studies. More research is warranted on who might benefit from bupropion as ATSUD treatment.

The fourth wave of the overdose crisis: Examining the prominent role of psychomotor stimulants with and without fentanyl

The current overdose and broader public health crisis involving illicit drug use is often referred to as the "opioid" or "fentanyl" crisis. Clearly there is extensive data on the profound damage done by opioids over the past 20 years and specifically by fentanyl in the past 5 years. However, there is an extensive array of data that suggests there is more to the current crisis than opioids/fentanyl. Much recent evidence indicates that methamphetamine and cocaine are playing a substantial and increasing role in the illicit drug crisis in the US-the 4th wave. This paper reviews data that illustrate the role of psychomotor stimulants in fatal overdoses, nonfatal overdoses, and emergency department visits. Despite the major detrimental role that stimulants are having on the public health in the US in 2023, there is virtually no evidence-based treatment available in practice for people with stimulant use disorder (StimUD). Although there are no medications with FDA-approval for the treatment of StimUD, there is a behavioral treatment, contingency management (CM), with over 3 decades of robust research supporting its efficacy for individuals with StimUD. Despite the overwhelming evidence supporting CM, it is not being widely used in routine treatment outside the VA healthcare system. This paper reviews some of the (a) evidence for CM, (b) CM protocol design elements that require consideration, (c) current obstacles to the widespread implementation of CM, and (d) strategies for addressing these obstacles. Overcoming these obstacles is a priority to allow routine use of CM as a treatment for StimUD.

A gender-based secondary analysis of the ADAPT-2 combination naltrexone and bupropion treatment for methamphetamine use disorder trial

BACKGROUND AND AIMS

Socio-cultural (gender) and biological (sex)-based differences contribute to psychostimulant susceptibility, potentially affecting treatment responsiveness among women with methamphetamine use disorder (MUD). The aims were to measure (i) how women with MUD independently and compared with men respond to treatment versus placebo and (ii) among women, how the hormonal method of contraception (HMC) affects treatment responsiveness.

DESIGN

This was a secondary analysis of ADAPT-2, a randomized, double-blind, placebo-controlled, multicenter, two-stage sequential parallel comparison design trial.

SETTING

United States.

PARTICIPANTS

This study comprised 126 women (403 total participants); average age = 40.1 years (standard deviation = 9.6) with moderate to severe MUD.

INTERVENTIONS

Interventions were combination intramuscular naltrexone (380 mg/3 weeks) and oral bupropion (450 mg daily) versus placebo.

MEASUREMENTS

Treatment response was measured using a minimum of three of four negative methamphetamine urine drug tests during the last 2 weeks of each stage; treatment effect was the difference between weighted treatment responses of each stage.

FINDINGS

At baseline, women used methamphetamine intravenously fewer days than men [15.4 versus 23.1% days, P = 0.050, difference = -7.7, 95% confidence interval (CI) = -15.0 to -0.3] and more women than men had anxiety (59.5 versus 47.6%, P = 0.027, difference = 11.9%, 95% CI = 1.5 to 22.3%). Of 113 (89.7%) women capable of pregnancy, 31 (27.4%) used HMC. In Stage 1 29% and Stage 2 5.6% of women on treatment had a response compared with 3.2% and 0% on placebo, respectively. A treatment effect was found independently for females and males (P < 0.001); with no between-gender treatment effect (0.144 females versus 0.100 males; P = 0.363, difference = 0.044, 95% CI = -0.050 to 0.137). Treatment effect did not differ by HMC use (0.156 HMC versus 0.128 none; P = 0.769, difference = 0.028, 95% CI -0.157 to 0.212).

CONCLUSIONS

Women with methamphetamine use disorder receiving combined intramuscular naltrexone and oral bupropion treatment achieve greater treatment response than placebo. Treatment effect does not differ by HMC.

Efficacy of bupropion and cognitive behavioral therapy in the treatment of methamphetamine use disorder: a systematic review and meta-analysis

OBJECTIVES

We assessed the efficacy of cognitive behavioral therapy and bupropion compared to cognitive behavioral therapy alone for methamphetamine use disorder.

METHODS

The selection criteria for this systematic review study with meta-analysis were randomized clinical trials on the efficacy of cognitive behavioral therapy and bupropion in the treatment for methamphetamine use disorder (assessed by urine metabolites). The search was conducted in PubMed, PubMed Central, LILACS, SciELO, Cochrane Library, SCOPUS, Google Scholar, Ovid Medline, Clinicaltrials.gov, and the International Clinical Trials Registry Platform. The primary outcome was relapse. Risk of bias was assessed with the RoB 2 tool. The results of each clinical trial were input into an Excel spreadsheet. We performed a meta-analysis using relative risk and a 95%CI.

RESULTS

Of the 597 initial articles (498 after removing duplicate records), five were included in the meta-analysis, with an aggregate sample of 539 patients. An overall relative risk of 0.91 (95%CI 0.78-1.05) was estimated for relapse.

CONCLUSION

Our study limitations included publication bias and heterogeneous populations. We found no evidence that cognitive behavioral therapy and bupropion reduced the risk of relapse compared to cognitive behavioral therapy and placebo.

The health needs of people leaving prison with a history of methamphetamine and/or opioid use

INTRODUCTION

Methamphetamine use is more common than opioid use among prison entrants in some countries, including Australia, yet most research and policy focuses on opioid use. This suggests that traditional opioid-focused interventions are no longer appropriate for the majority of this group in countries such as Australia. To inform policy and practice, we compared socio-demographic characteristics and health needs of people leaving prison with a history of methamphetamine use and/or opioid use.

METHODS

A cross-sectional survey of incarcerated adults administered the World Health Organization Alcohol, Smoking and Substance Involvement Screening Test was used to identify moderate-/high-risk methamphetamine use (n = 909), opioid use (n = 115) or combined methamphetamine/opioid use (n = 356) before incarceration. We compared groups using modified log-linked Poisson regression with robust error variance.

RESULTS

Compared to the opioid-only group, the methamphetamine-only group were: significantly more often aged <25 years; significantly more likely to identify as Indigenous; significantly less likely to have a history of prior incarceration, drug injection or overdose. A significantly lower proportion of methamphetamine-only and methamphetamine-and-opioid participants self-reported current hepatitis C infection compared to opioid-only participants. A majority of participants in all groups screened positive for current psychological distress according to the K10.

DISCUSSION AND CONCLUSIONS

People leaving prison with a history of methamphetamine use differ from opioid users with respect to demographics, patterns of substance use and related health concerns. Treatment and harm reduction efforts for people who experience incarceration must respond to patterns of drug use in this population, and invest at scale in coordinated, continuous services for co-occurring substance use and mental health problems.

Bupropion Slow Release vs Placebo With Adaptive Incentives for Cocaine Use Disorder in Persons Receiving Methadone for Opioid Use Disorder: A Randomized Clinical Trial

IMPORTANCE

Opioid-stimulant co-use is a common problem with few evidence-based treatments.

OBJECTIVE

To examine bupropion slow release (SR) enhancement of a tailored abstinence incentive program for stimulant use in persons with opioid use disorder.

DESIGN, SETTING, AND PARTICIPANTS

This 26-week, double-blind, placebo-controlled randomized clinical trial with a 4-week follow-up period was conducted at 4 methadone treatment programs in Baltimore, Maryland. Included participants were persons receiving methadone for the treatment of opioid use disorder with past 3-month cocaine use and current cocaine use disorder between March 2015 and September 2019. Data were analyzed from November 2020 through August 2022.

INTERVENTIONS

A 6-week incentive induction period with monetary incentives for evidence of cocaine abstinence during thrice-weekly urine testing was conducted. Persons achieving 2 weeks of consecutive abstinence during induction were assigned to the relapse prevention group (20 individuals); otherwise, individuals were assigned to the abstinence initiation group (60 individuals). Participants were randomized within incentive groups to bupropion SR (150 mg oral twice daily; 40 participants) or placebo (40 participants). Incentives were available until week 26, and study medication ended week 30.

MAIN OUTCOMES AND MEASURES

The mean percentage of participants with cocaine abstinence (by negative urinalysis or self-report) during weeks 7 to 26 (ie, the incentive intervention period) and 27 to 30 (ie, the follow-up period) and the percentage of participants testing negative for cocaine at weeks 26 and 30 were assessed. Main effects of medication collapsed across incentive conditions and sensitivity analyses of medications within incentive conditions were assessed. Analyses were conducted in the modified intention-to-treat sample (ie, 80 individuals who received ≥1 dose of study medication) and completers (ie, 52 individuals who completed ≥1 visit during week 30).

RESULTS

Among 80 participants (42 Black [52.5% ] and 35 White [43.8%]; mean [SD] age, 45.7 (9.4) years; 52 males [65.0%]) receiving methadone for opioid use disorder, 40 participants were randomized to receive bupropion SR and 40 participants to receive placebo. No significant difference on urinalysis or self-reported cocaine use was observed between medication groups. Sensitivity analyses revealed differential patterns for incentive subgroups. Participants in the relapse prevention group had high abstinence (>80%; eg, during weeks 7-26 in the modified intention-to-treat analysis, 410 of 456 samples [89.9%] from participants in the bupropion SR group tested negative for cocaine) throughout the trial regardless of whether they were randomized to bupropion SR or placebo. Participants in the abstinence initiation group had better outcomes with bupropion SR than placebo throughout the trial (mean [SD] total number of samples testing negative for cocaine, 30.3 [21.6] samples for bupropion SR vs 17.1 [14.9] samples for placebo; P = .05) and more participants receiving bupropion SR than placebo were abstinent at the end of the study (20 of 30 participants [66.7%] vs 9 of 30 participants [30.0%]; P = .04).

CONCLUSIONS AND RELEVANCE

In this randomized clinical trial, an overall benefit for bupropion SR vs placebo when combined with a financial abstinence incentive program was not observed. Results among incentive subgroups suggest that continued evaluation of medications, including bupropion SR, for stimulant treatment using a tailored approach that factors early abstinence into study design and interpretation may be needed.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT02111798.

Estimating the impact of stimulant use on initiation of buprenorphine and extended-release naltrexone in two clinical trials and real-world populations

BACKGROUND

Co-use of stimulants and opioids is rapidly increasing. Randomized clinical trials (RCTs) have established the efficacy of medications for opioid use disorder (MOUD), but stimulant use may decrease the likelihood of initiating MOUD treatment. Furthermore, trial participants may not represent "real-world" populations who would benefit from treatment.

METHODS

We conducted a two-stage analysis. First, associations between stimulant use (time-varying urine drug screens for cocaine, methamphetamine, or amphetamines) and initiation of buprenorphine or extended-release naltrexone (XR-NTX) were estimated across two RCTs (CTN-0051 X:BOT and CTN-0067 CHOICES) using adjusted Cox regression models. Second, results were generalized to three target populations who would benefit from MOUD: Housed adults identifying the need for OUD treatment, as characterized by the National Survey on Drug Use and Health (NSDUH); adults entering OUD treatment, as characterized by Treatment Episodes Dataset (TEDS); and adults living in rural regions of the U.S. with high rates of injection drug use, as characterized by the Rural Opioids Initiative (ROI). Generalizability analyses adjusted for differences in demographic characteristics, substance use, housing status, and depression between RCT and target populations using inverse probability of selection weighting.

RESULTS

Analyses included 673 clinical trial participants, 139 NSDUH respondents (weighted to represent 661,650 people), 71,751 TEDS treatment episodes, and 1,933 ROI participants. The majority were aged 30-49 years, male, and non-Hispanic White. In RCTs, stimulant use reduced the likelihood of MOUD initiation by 32% (adjusted HR [aHR] = 0.68, 95% CI 0.49-0.94, p = 0.019). Stimulant use associations were slightly attenuated and non-significant among housed adults needing treatment (25% reduction, aHR = 0.75, 0.48-1.18, p = 0.215) and adults entering OUD treatment (28% reduction, aHR = 0.72, 0.51-1.01, p = 0.061). The association was more pronounced, but still non-significant among rural people injecting drugs (39% reduction, aHR = 0.61, 0.35-1.06, p = 0.081). Stimulant use had a larger negative impact on XR-NTX initiation compared to buprenorphine, especially in the rural population (76% reduction, aHR = 0.24, 0.08-0.69, p = 0.008).

CONCLUSIONS

Stimulant use is a barrier to buprenorphine or XR-NTX initiation in clinical trials and real-world populations that would benefit from OUD treatment. Interventions to address stimulant use among patients with OUD are urgently needed, especially among rural people injecting drugs, who already suffer from limited access to MOUD.

Polysubstance use before and during treatment with medication for opioid use disorder: Prevalence and association with treatment outcomes

OBJECTIVE

Polysubstance use may complicate treatment outcomes for individuals who use opioids. This research aimed to examine the prevalence of polysubstance use in an opioid use disorder treatment trial population and polysubstance use's association with opioid relapse and craving.

METHODS

This study is a secondary data analysis of individuals with opioid use disorder who received at least one dose of medication (n = 474) as part of a 24-week, multi-site, open label, randomized Clinical Trials Network study (CTN0051, X:BOT) comparing the effectiveness of extended-release naltrexone versus buprenorphine. Models examined pretreatment polysubstance use and polysubstance use during the initial 4 weeks of treatment on outcomes of relapse by week 24 of the treatment trial and opioid craving.

RESULTS

Polysubstance use was generally not associated with treatment outcomes of opioid relapse and craving. Proportion of days of pretreatment sedative use was associated with increased likelihood of opioid relapse (OR: 1.01, 95 % CI: 1.00-1.02). Proportion of days of cocaine use during the initial 4 weeks of treatment was associated with increased likelihood of opioid relapse (OR: 1.05, 95 % CI: 1.01-1.09) but this effect was no longer significant once the potential of confounding by opioid use was considered. Sedative use during initial 4 weeks of treatment was associated with increased opioid craving (b: 0.77, 95 % CI: 0.01-1.52). The study found no other significant relationships.

CONCLUSIONS

In the current study population, polysubstance use was only marginally associated with 24-week treatment outcomes.

Helpful or Harmful? The Therapeutic Potential of Medications with Varying Degrees of Abuse Liability in the Treatment of Substance Use Disorders

Purpose of Review

This review summarizes recent clinical trial research on pharmacological treatments for substance use disorders, with a specific focus on agents with potential abuse liability.

Recent Findings

Pharmacological treatments for substance use disorders may include gabapentinoids, baclofen, modafinil, ketamine, cannabinoids, gamma-hydroxybutyrate, and psychedelics. Gabapentinoids may decrease negative subjective effects of withdrawal in alcohol and cannabis use disorders. Cannabinoids similarly appear to decrease use and withdrawal symptoms in cannabis use disorder, while research shows stimulant medications may reduce cravings and increase abstinence in cocaine use disorder. Ketamine and psychedelics may help treat multiple substance use disorders. Ketamine may reduce withdrawal symptoms, promote abstinence, and diminish cravings in alcohol and cocaine use disorders and psychedelics may promote remission, decrease use, and reduce cravings in alcohol and opioid use disorders.

Summary

Regardless of current regulatory approval statuses and potentials for abuse, multiple agents should not be dismissed prematurely as possible treatments for substance use disorders. However, further clinical research is needed before effective implementation can begin in practice.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40429-022-00432-9.

The role of enkephalinergic systems in substance use disorders

Enkephalin, an endogenous opioid peptide, is highly expressed in the reward pathway and may modulate neurotransmission to regulate reward-related behaviors, such as drug-taking and drug-seeking behaviors. Drugs of abuse also directly increase enkephalin in this pathway, yet it is unknown whether or not changes in the enkephalinergic system after drug administration mediate any specific behaviors. The use of animal models of substance use disorders (SUDs) concurrently with pharmacological, genetic, and molecular tools has allowed researchers to directly investigate the role of enkephalin in promoting these behaviors. In this review, we explore neurochemical mechanisms by which enkephalin levels and enkephalin-mediated signaling are altered by drug administration and interrogate the contribution of enkephalin systems to SUDs. Studies manipulating the receptors that enkephalin targets (e.g., mu and delta opioid receptors mainly) implicate the endogenous opioid peptide in drug-induced neuroadaptations and reward-related behaviors; however, further studies will need to confirm the role of enkephalin directly. Overall, these findings suggest that the enkephalinergic system is involved in multiple aspects of SUDs, such as the primary reinforcing properties of drugs, conditioned reinforcing effects, and sensitization. The idea of dopaminergic-opioidergic interactions in these behaviors remains relatively novel and warrants further research. Continuing work to elucidate the role of enkephalin in mediating neurotransmission in reward circuitry driving behaviors related to SUDs remains crucial.

COVID-19 Vaccination Status and Concerns Among People Who Use Drugs in Oregon

OBJECTIVES

The objective of this study was to examine COVID-19 vaccination acceptance and explore reasons for COVID-19 vaccine hesitancy among people who use drugs (PWUDs), a population with increased COVID-19 transmission and morbidity.

METHODS

We conducted semi-structured in-depth interviews with PWUDs in 7 Oregon counties from May 11 to June 25, 2021. Participants (n = 34) were recruited in partnership with syringe service programs and local community organizations staff, participant-referrals, and flyer advertising. Research staff conducted interviews via telephone to assess participants' acceptance of the COVID-19 vaccine, find knowledge gaps where new educational information about vaccination would be helpful, and identify who would be perceived as a trustworthy source of information. Interviews were transcribed and coded using thematic analysis with a deductive approach.

RESULTS

Most participants had not received the COVID-19 vaccine and were not planning on or were unsure about receiving it. Participants were mistrustful of the rapid COVID-19 vaccine development process, the agencies involved in the development, and vaccines in general. Participants shared varied and contrasting responses about who they would trust to provide information about the COVID-19 vaccine, including peer recovery support specialists, doctors, or other health care professionals, and specified federal agencies or media outlets.

CONCLUSIONS

As addiction medicine and public health staff continue to respond to the evolving impacts of COVID-19, vaccination planning should be tailored to the unique needs of PWUD to increase COVID-19 vaccine acceptance in this high-risk population.

Development and multimodal validation of a substance misuse algorithm for referral to treatment using artificial intelligence (SMART-AI): a retrospective deep learning study

Background

Substance misuse is a heterogeneous and complex set of behavioural conditions that are highly prevalent in hospital settings and frequently co-occur. Few hospital-wide solutions exist to comprehensively and reliably identify these conditions to prioritise care and guide treatment. The aim of this study was to apply natural language processing (NLP) to clinical notes collected in the electronic health record (EHR) to accurately screen for substance misuse.

Methods

The model was trained and developed on a reference dataset derived from a hospital-wide programme at Rush University Medical Center (RUMC), Chicago, IL, USA, that used structured diagnostic interviews to manually screen admitted patients over 27 months (between Oct 1, 2017, and Dec 31, 2019; n=54 915). The Alcohol Use Disorder Identification Test and Drug Abuse Screening Tool served as reference standards. The first 24 h of notes in the EHR were mapped to standardised medical vocabulary and fed into single-label, multilabel, and multilabel with auxillary-task neural network models. Temporal validation of the model was done using data from the subsequent 12 months on a subset of RUMC patients (n=16 917). External validation was done using data from Loyola University Medical Center, Chicago, IL, USA between Jan 1, 2007, and Sept 30, 2017 (n=1991 adult patients). The primary outcome was discrimination for alcohol misuse, opioid misuse, or non-opioid drug misuse. Discrimination was assessed by the area under the receiver operating characteristic curve (AUROC). Calibration slope and intercept were measured with the unreliability index. Bias assessments were performed across demographic subgroups.

Findings

The model was trained on a cohort that had 3·5% misuse (n=1 921) with any type of substance. 220 (11%) of 1921 patients with substance misuse had more than one type of misuse. The multilabel convolutional neural network classifier had a mean AUROC of 0·97 (95% CI 0·96–0·98) during temporal validation for all types of substance misuse. The model was well calibrated and showed good face validity with model features containing explicit mentions of aberrant drug-taking behaviour. A false-negative rate of 0·18–0·19 and a false-positive rate of 0·03 between non-Hispanic Black and non-Hispanic White groups occurred. In external validation, the AUROCs for alcohol and opioid misuse were 0·88 (95% CI 0·86–0·90) and 0·94 (0·92–0·95), respectively.

Interpretation

We developed a novel and accurate approach to leveraging the first 24 h of EHR notes for screening multiple types of substance misuse.

Funding

National Institute On Drug Abuse, National Institutes of Health.

A Study of the MTHFR Gene Prevalence in a Rural Tennessee Opioid Use Disorder Treatment Center Population

Background: Opioid Use Disorder (OUD) has been linked to dopamine and the neurological reward centers. Methylenetetrahydrofolate reductase (MTHFR) is an enzyme involved in the production of many neurotransmitters such as dopamine. As such, MTHFR variants that lead to decreased production of neurotransmitters may play a role in OUD. However, lacunae exist for characterizing the prevalence of the MTHFR mutations in an OUD population. The objective of this study was to determine prevalence of the MTHFR gene mutations in a rural Tennessean population with OUD. Methods: This study was a retrospective cohort of individuals with OUD that evaluated the prevalence of MTHFR variants. Patients were categorized as normal, homozygous C677T, heterozygous C677T, homozygous A1298C, or heterozygous A1298C. The primary outcome was a qualitative comparison of the prevalence of each of the MTHFR variants in our cohort to the publicly reported MTHR polymorphism prevalence. Secondary outcomes include race and ethnicity differences as well as stimulant use differences for each of the variants. Results: A total of 232 patients undergoing care for opioid use disorder were included in the study. Of those included, 30 patients had a normal MTHFR allele and 202 had a variant MTHFR allele. Overall, the prevalence of any MTHFR variant was 87.1% (95% CI 82.6–91.4%). When comparing those with a normal MTHFR allele to those with any MTHFR variant, there was no difference in age, sex, race and ethnicity, or stimulant use. Conclusion: The overall prevalence of MTHFR variants in patients with opioid use disorders is high.

Acute effects of amphetamine and related psychostimulants on impulsivity: a systematic review of clinical trials

Evidence for acute amphetamine effects on behavioural impulsivity in healthy populations remains elusive and, at times, mixed. This review collates and reviews the clinical literature on the acute effects of amphetamines on measures of behavioural impulsivity in healthy adults. Randomised and placebo-controlled clinical trials that assessed behavioural impulsivity following the administration of an acute dose of amphetamine or a related psychostimulant (including amphetamine analogues and methylphenidate) were eligible for inclusion. The EBSCOHost, SCOPUS, PsychNet, Web of Science and ProQuest databases were searched from inception to 26 April 2021. Study selection, data extraction and the Cochrane risk of bias assessments were conducted by two independent reviewers. Reporting follows PRISMA guidelines, and the review was registered a priori on the PROSPERO database (Registration No: CRD42021249861). A total of 20 studies were included, comprising a total of 737 participants. Overall, results indicate that low-moderate doses of amphetamine and related psychostimulants may improve (i.e., reduce) impulsive responding without compromising performance, reflecting enhanced inhibitory control of behaviour. These effects are mild and appear most pronounced in individuals with high baseline impulsivity. This review highlights the need for greater consistency in behavioural task selection and future high-quality and well-designed studies to address current concerns around growing prescription psychostimulant use and misuse.

Trends in comorbid opioid and stimulant use disorders among Veterans receiving care from the Veterans Health Administration, 2005-2019

BACKGROUND

Identifying solutions to the continued rise in overdose deaths is a public health priority. However, there is evidence of change in recent substance type associated with morbidity and mortality. To better understand the continued rise in overdose deaths, in particular those attributed to opioid and stimulant use disorders, increased knowledge of patterns of use is needed.

METHODS

Retrospective cohort study of Veterans diagnosed with an opioid or stimulant use disorder between 2005 and 2019. The outcome of interest was diagnosis of substance use disorders, specifically examining combinations of opioid and stimulant use disorders among this population.

RESULTS

A total of 1932,188 Veterans were diagnosed with at least one substance use disorder (SUD) during the study period, 2005 through 2019. While the annual prevalence of opioid use disorder (OUD) diagnoses increased more than 155%, OUD diagnoses absent of any other SUD diagnosis increased by an average of 6.9% (95% CI, 6.4, 7.5) per year between 2005 and 2019. Between 2011 and 2019, diagnoses of co-morbid methamphetamine use disorder (MUD) and OUD increased at a higher rate than other SUD combinations.

CONCLUSIONS

The prevalence of comorbid SUD, in particular co-occurring opioid and methamphetamine use disorder, increased at a higher rate than other combinations between 2005 and 2019. These findings underscore the urgent need to offer patients a combination of evidence-based treatments for each co-morbid SUD, such MOUD and contingency management for persons with comorbid opioid and methamphetamine use disorders.

U.S. older adults' heroin and psychostimulant use treatment admissions, 2012-2019: Sociodemographic and clinical characteristics

BACKGROUND

Increases in U.S. older adults' nonprescription opioid and psychostimulant use call for examining their treatment admissions for these substances.

METHODS

Using admissions age 55 + involving heroin (N = 299,073) from the 2012-2019 Treatment Episode Data Set-Admissions, we examined trends and sociodemographic and clinical characteristics of three groups: (1) heroin-only admissions (i.e., not involving cocaine or methamphetamine), (2) heroin-cocaine admissions, and (3) heroin-methamphetamine admissions. Bivariable and multivariable logistic regression analyses were conducted to examine the research questions.

RESULTS

Between 2012 and 2019, the numbers of both heroin-only and heroin-cocaine admissions increased 2.3-fold and heroin-methamphetamine admissions increased seven-fold. First time heroin-methamphetamine admissions increased 18-fold. Heroin-methamphetamine admissions were concentrated in the Western region and heroin-cocaine admissions in the Northeastern region. Multivariable analyses showed a nearly 6 times higher relative risk ratio (RRR; 95% CI=5.24-6.74) for heroin-methamphetamine vs. heroin-only admissions in 2019 compared to 2012. Being non-Hispanic Black, compared to non-Hispanic White, was associated with a RRR of 2.4 (95% CI=2.34-2.46) for heroin-cocaine admissions and a RRR of 0.14 (95% CI=0.12-0.15) for heroin-methamphetamine admissions. Late-onset heroin use, experience of homelessness and other psychiatric problems, and past 30-day arrest episodes were associated with a higher likelihood of heroin-cocaine and heroin-methamphetamine admissions, while injection drug use (IDU) was associated with a higher likelihood of heroin-methamphetamine admissions only.

CONCLUSIONS

Healthcare providers should assess and monitor psychostimulant, methamphetamine in particular, use among older adults. Those who use heroin and psychostimulants should receive substance use treatment and help to secure stable housing and meet other living needs.

"It's called overamping": experiences of overdose among people who use methamphetamine

BACKGROUND

The USA is experiencing increases in methamphetamine use and methamphetamine-related or attributed deaths. In the current study, we explore qualitative narratives of methamphetamine overdose and strategies used by people who use drugs to reduce the undesirable effects associated with methamphetamine use.

METHODS

We conducted 21 qualitative interviews with people over the age of 18 who reported using methamphetamine in the previous 3 months in Nevada and New Mexico. Interviews were recorded, transcribed, and analyzed using qualitative thematic analysis.

RESULTS

Respondents described a constellation of psychological and physical symptoms that they characterized as "overamping," experienced on a continuum from less to more severe. Reports of acute, fatal methamphetamine overdose were rare. Few reported seeking medical attention for undesirable effects (usually related to psychological effects). General self-care strategies such as sleeping and staying hydrated were discussed.

CONCLUSIONS

When asked directly, our respondents claimed that acute, fatal methamphetamine overdose is rare or even impossible. However, they described a number of undesirable symptoms associated with overconsumption of methamphetamine and had few clinical or harm reduction strategies at their disposal. Addressing this current wave of drug-related deaths will require attention to the multiple factors that structure experiences of methamphetamine "overdose," and a collaborative effort with PWUDs to devise effective harm reduction and treatment strategies.

Dopamine Supersensitivity: A Novel Hypothesis of Opioid-Induced Neurobiological Mechanisms Underlying Opioid-Stimulant Co-use and Opioid Relapse

Emergent harms presented by the co-use of opioids and methamphetamine highlight the broader public health challenge of preventing and treating opioid and stimulant co-use. Development of effective therapeutics requires an understanding of the physiological mechanisms that may be driving co-use patterns, specifically the underlying neurobiology of co-use and how they may facilitate (or be leveraged to prevent) continued use patterns. This narrative review summarizes largely preclinical data that demonstrate clinically-meaningful relationships between the dopamine and opioid systems with direct implications for opioid and stimulant co-use. Synthesized conclusions of this body of research include evidence that changes in the dopamine system occur only once physical dependence to opioids develops, that the chronicity of opioid exposure is associated with the severity of changes, and that withdrawal leaves the organism in a state of substantive dopamine deficit that persists long after the somatic or observed signs of opioid withdrawal appear to have resolved. Evidence also suggests that dopamine supersensitivity develops soon after opioid abstinence and results in increased response to dopamine agonists that increases in magnitude as the abstinence period continues and is evident several weeks into protracted withdrawal. Mechanistically, this supersensitivity appears to be mediated by changes in the sensitivity, not quantity, of dopamine D2 receptors. Here we propose a neural circuit mechanism unique to withdrawal from opioid use with implications for increased stimulant sensitivity in previously stimulant-naïve or inexperienced populations. These hypothesized effects collectively delineate a mechanism by which stimulants would be uniquely reinforcing to persons with opioid physical dependence, would contribute to the acute opioid withdrawal syndrome, and could manifest subjectively as craving and/or motivation to use that could prompt opioid relapse during acute and protracted withdrawal. Preclinical research is needed to directly test these hypothesized mechanisms. Human laboratory and clinical trial research is needed to explore these clinical predictions and to advance the goal of developing treatments for opioid-stimulant co-use and/or opioid relapse prevention and withdrawal remediation.

Understanding Stimulant Use and Use Disorders in a New Era

Extending from the triple wave epidemic of opioid-related overdose deaths, a fourth wave of high mortality involving methamphetamine and cocaine use has been gathering force. This article provides a review of the published literature on stimulants including epidemiology, pharmacology, neurobiology, medical and psychiatric consequences, withdrawal management, and medical and behavioral treatments.

A cross-sectional survey of potential factors, motivations, and barriers influencing research participation and retention among people who use drugs in the rural USA

BACKGROUND

Despite high morbidity and mortality among people who use drugs (PWUD) in rural America, most research is conducted within urban areas. Our objective was to describe influencing factors, motivations, and barriers to research participation and retention among rural PWUD.

METHODS

We recruited 255 eligible participants from community outreach and community-based, epidemiologic research cohorts from April to July 2019 to participate in a cross-sectional survey. Eligible participants reported opioid or injection drug use to get high within 30 days and resided in high-needs rural counties in Oregon, Kentucky, and Ohio. We aggregated response rankings to identify salient influences, motivations, and barriers. We estimated prevalence ratios to assess for gender, preferred drug use, and geographic differences using log-binomial models.

RESULTS

Most participants were male (55%) and preferred methamphetamine (36%) over heroin (35%). Participants reported confidentiality, amount of financial compensation, and time required as primary influential factors for research participation. Primary motivations for participation include financial compensation, free HIV/HCV testing, and contribution to research. Changed or false participant contact information and transportation are principal barriers to retention. Respondents who prefer methamphetamines over heroin reported being influenced by the purpose and use of their information (PR = 1.12; 95% CI: 1.00, 1.26). Females and Oregonians (versus Appalachians) reported knowing and wanting to help the research team as participation motivation (PR = 1.57; 95% CI: 1.09, 2.26 and PR = 2.12; 95% CI: 1.51, 2.99).

CONCLUSIONS

Beyond financial compensation, researchers should emphasize confidentiality, offer testing and linkage with care, use several contact methods, aid transportation, and accommodate demographic differences to improve research participation and retention among rural PWUD.

A qualitative examination of recent increases in methamphetamine use in a cohort of rural people who use drugs

INTRODUCTION

Rising rates of methamphetamine use among populations using opioids is an escalating public health concern. The purpose of this manuscript is to identify socioecologic factors driving increases in methamphetamine use among Appalachian Kentucky adults with a history of opioid use.

METHODS

Semi-structured qualitative interviews were conducted among 20 Appalachian Kentuckians in the Social Network of Appalachian Peoples (SNAP) cohort who reported lifetime opioid use and past 30-day methamphetamine use. Interviews focused on initiation of methamphetamine use, factors that influence methamphetamine use at the individual, interpersonal, community and society levels.

RESULTS

Participants reported using methamphetamine to self-treat underlying issues, including withdrawal from opioids, chronic pain, and emotional distress. Initiation of use was most often facilitated through their drug networks. Participants reported that methamphetamine was widely available and affordable in their community. Several participants with extensive histories of non-medical prescription opioid (NMPO) use described transitioning to methamphetamine as their drug of choice as opioids became less available in their community. Participants also reported economic distress and lack of recreational opportunities as drivers of increased methamphetamine use.

DISCUSSION

Recent increases in methamphetamine use among those with a history of opioid use is facilitated by methamphetamine's relative availability and affordability. Methamphetamine use was also highly influenced by societal factors such as economic deprivation and policies that decreased availability of NMPOs. Surging methamphetamine use exacerbates inequities in addiction care brought to light by the opioid epidemic. Interventions aimed at addressing the socioecological drivers of methamphetamine use among people who use opioids are warranted.

Pharmacotherapy treatment of stimulant use disorder

Stimulant use disorder (SUD) is a public health problem in the United States that is associated with increased morbidity and mortality. Psychosocial interventions, such as cognitive behavioral therapy and contingency management, are the main treatment modality for SUDs and no pharmacotherapy is currently FDA approved for this indication. Although some medications show promising data for the treatment of SUD, the evidence remains inconsistent, and the clinical application is limited due to the heterogenicity of the population and the lack of studies in patients with various comorbidities. Selection of pharmacotherapy treatment for methamphetamine intoxication, persistent methamphetamine-associated psychosis with methamphetamine use disorder, and cocaine use disorder in patients with co-occurring OUD are discussed in 3 patient cases.

Characteristics and health care events of patients admitted to treatment for both heroin and methamphetamine compared to patients admitted for heroin only

INTRODUCTION

Co-occurring heroin and methamphetamine use is a growing public health problem. This study assessed the characteristics of Medicaid patients admitted to substance use disorder (SUD) treatment programs for heroin and methamphetamine use compared with patients admitted for heroin only.

METHODS

The study identified patients who entered treatment for heroin and methamphetamine and those admitted for heroin only between 2014 and 2017 from the Oregon Treatment Episode Data Set linked with Medicaid enrollment, and medical and pharmacy claims. We used a cross-sectional design to compare demographics, type of treatment, and substance use characteristics between the two groups. We used logistic regression models to assess differences in the odds of opioid-related and all-cause adverse events.

RESULTS

Among the 3802 study sample, 2004 (53%) were admitted for both heroin and methamphetamine use. The heroin and methamphetamine group were more likely to be younger, female, White or American Indian/Alaska Native; and had more comorbidities than patients admitted for heroin only. Patients admitted for heroin and methamphetamine treatment were less likely to receive any medication for opioid use disorder (MOUD) (56% vs 75%, p < 0.001) and received fewer days of MOUD treatment (mean 188 vs. 265 days, p < 0.001) compared to the heroin only group. The heroin and methamphetamine group were more likely to receive buprenorphine (28.1% vs 24.2%) and less likely to receive methadone (39.9% vs 62.5%). The heroin and methamphetamine group began use at a younger age, used and injected more frequently than those admitted for heroin only. Patients treated for heroin and methamphetamine had 17% lower odds of OUD-related adverse events (aOR 0.83; 95% CI 0.70-0.99) and 52% higher odds of all-cause adverse events (aOR 1.52; 95% CI 1.14-2.03) relative to the heroin only group.

CONCLUSION

Patients admitted for both heroin and methamphetamine reported greater addiction severity (more frequent use, earlier onset of use, and injection use), yet less commonly received MOUD compared to those who were admitted for heroin only. These findings indicate substantial missed opportunities for MOUD treatment even among people who successfully engage with the SUD treatment system.

Care-engaged individuals with polysubstance use in Northeastern US are undertreated for methamphetamine use disorder: a retrospective cohort study

BACKGROUND

Stimulant use has increased across the US, with concomitant opioid and methamphetamine use doubling between 2011 and 2017. Shifting patterns of polysubstance use have led to rising psychostimulant-involved deaths. While it is known that individuals who use methamphetamine require greater access to treatment, there is still little known about methamphetamine use and treatment among individuals who are already engaged in outpatient substance use treatment.

OBJECTIVES

To characterize care-engaged individuals who use methamphetamine to guide harm reduction and treatment strategies.

METHODS

Retrospective cohort study of individuals at a large academic medical center in Massachusetts with ≥ 2 positive methamphetamine oral fluid toxicology tests between August 2019 and January 2020. We performed descriptive analysis of sociodemographic, medical, and drug use characteristics and a comparative analysis of injection methamphetamine use versus other routes of use.

RESULTS

Included were 71 individuals [56 male (80%), 66 non-Hispanic white (94%), median age 36 (IQR 30-42)]. Nearly all had opioid (94%) and stimulant use disorder (92%). Most had (93%) or were (83%) being treated with medications for opioid use disorder, but few received pharmacologic treatment for methamphetamine use disorder (24%). None received contingency management treatment. People who inject methamphetamine (68%) were more likely to have a history of overdose (91% vs. 70%; p = 0.02), have HCV (94% vs. 52%; p < 0.01), use fentanyl (93% vs. 65%; p = 0.02), and engage in sex work (19% vs. 0%; p = 0.03) compared to those who used via other routes. Both groups had prevalent homelessness (88% vs. 73%; p = 0.15), incarceration (81% vs. 64%; p = 0.11), depression (94% vs. 87%; p = 0.34), and bacteremia (27% vs. 22%; p = 0.63).

CONCLUSIONS

Individuals in our study had high prevalence of polysubstance use, particularly concomitant methamphetamine and opioid use. Individuals who were well connected to substance use treatment for their opioid use were still likely to be undertreated for their methamphetamine use disorder and would benefit from greater access to contingency management treatment, harm reduction resources, and resources to address adverse social determinants of health.

The continued rise of methamphetamine use among people who use heroin in the United States

BACKGROUND

Methamphetamine use is a growing public health concern in the United States. Prior analyses with nationally representative data from 2015 to 2017 suggested that increases in methamphetamine use appeared largely selective to people using heroin. This analysis updated prior estimates to determine if trends are selectively persistent and how they compare to historical trends. We also evaluate sociodemographic risk factors associated with methamphetamine use among people using heroin.

METHODS

Data from the 2015-2019 National Surveys on Drug Use and Health (NSDUH) were analyzed. Data from the 2006-2014 NSDUH were summarized for historical trends. Past month and past year methamphetamine use prevalence was determined within populations using heroin as well as those using other drugs (e.g., cocaine, cannabis). Multivariable logistic models accounting for complex survey design evaluated predictors of methamphetamine use among people using heroin.

RESULTS

From 2015 to 2019, past month methamphetamine use increased from 9.0% to 44.0% within the population of people reporting past month heroin use. Similarly, past year methamphetamine use increased from 22.5% to 46.7% among those reporting past year heroin use. Risk factors for methamphetamine use among people using heroin included rurality, past year injection drug use, and serious mental illness.

CONCLUSIONS

A rapid, selective, and sustained increase in methamphetamine use is evident among people using heroin. These findings combined with similar findings in treatment admission and overdose data emphasize the need for increased attention to a specific type of high-risk use pattern in the United States, an issue that appears increasingly unlikely to naturally resolve.

'Resurgent', 'twin' or 'silent' epidemic? A select data overview and observations on increasing psycho-stimulant use and harms in North America

In the early 2000s, increasing prevalence of psycho-stimulant (e.g., crack/cocaine, methamphetamine) use and related harms, including severe adverse health outcomes, was observed among - mostly marginalized - populations of persons using illicit drugs in North America, underscoring an urgent need for interventions options towards improved prevention and treatment. By about 2010, however, the 'opioid crisis', featuring unprecedented use and public health burden, had accelerated into full force in North America, largely muting attention to the psycho-stimulant issue until recently. Recent surveillance data on drug use and related mortality/morbidity from the present decade has documented a marked resurgence of psycho-stimulant use and harms especially in at-risk populations, commonly in direct combination with opioids, across North America, resulting in a 'twin epidemic' comprised of opioids and psycho-stimulants We briefly review select epidemiological data indicators for these developments from the United States and Canada; in the latter jurisdiction, related evidence has been less prevalent and systematic but corroborating the same trends. Evidently, the (widely ongoing) focus on the 'opioid epidemic' as a 'mono-type' drug problem has become an anachronism that requires urgent and appropriate correction. We then briefly consider existing, evidence-based options for - prevention and treatment - interventions targeting psycho-stimulant use and harms, which are substantially more limited and/or less efficacious than those available for problematic opioid use, while presenting major gaps and challenges. The observed resurgence of psycho-stimulants may, indirectly, relate to recent efforts towards curtailing (medical) opioid availability, thereby accelerating demand and supply for both illicit opioids and psycho-stimulants. The presently unfolding 'twin epidemic' of opioids and psycho-stimulants, combined with limited intervention resources, presents an acute challenge for public health and may crucially undermine actively extensive efforts to reduce opioid-related health harms in North America.

Adults With Opioid and Methamphetamine Co-use Have Lower Odds of Completing Short-Term Residential Treatment Than Other Opioid Co-use Groups: A Retrospective Health Services Study

Objective: There is an increase in persons entering substance use treatment who co-use opioids and methamphetamines in recent years. Co-using these substances may negatively impact treatment retention in the residential setting. We explored predictors of adults completing short-term residential treatment among persons with primary opioid use disorder (OUD) who co-use either alcohol, benzodiazepines, cocaine, or methamphetamines. Methods: This study used the 2019 de-identified, publicly available Treatment Episode Dataset-Discharges. The sample included adults discharged from short-term residential treatment with primary OUD who co-used either alcohol, benzodiazepines, cocaine, or methamphetamines. The final sample size included 24,120 treatment episodes. Univariate statistics were used to describe the sample. Two logistic regression models were used to predict completing treatment. The first logistic regression model included the co-use groups as predictors and the second model added other demographic and treatment-relevant covariates. Results: A slight majority (51.4%) of the sample prematurely discharged from treatment. Compared to the other three co-use groups, the opioid and methamphetamine co-use group had the highest proportion of individuals who were women (45.0%), unemployed (62.5%), current injection drug use (76.0%), living in the Midwest (35.9%), living in the south (33.5%), and living in the west (15.5%). The opioid and methamphetamine co-use group also had the highest proportion of individuals not receiving medications for OUD (84.9%), not having a prior treatment episode (28.7%), and not completing treatment (57.4%). In the final logistic regression model, which included covariates, the opioid and alcohol (OR = 1.18, 95% CI = 1.080-1.287, p < 0.001), opioid and benzodiazepine (OR = 1.33, 95% CI = 1.213-1.455, p < 0.001), and opioid and cocaine (OR = 1.16, 95% CI = 1.075-1.240, p < 0.001) co-use groups had higher odds of completing treatment than the opioid and methamphetamine co-use group. Conclusions: Opioid and methamphetamine co-use may complicate short-term residential treatment retention. Future work should identify effective strategies to retain persons who co-use opioids and methamphetamines in treatment.

Intranasal Oxytocin for Stimulant Use Disorder Among Male Veterans Enrolled in an Opioid Treatment Program: A Randomized Controlled Trial

The increasing prevalence of illicit stimulant use among those in opioid treatment programs poses a significant risk to public health, stimulant users have the lowest rate of retention and poorest outcomes among those in addiction treatment, and current treatment options are limited. Oxytocin administration has shown promise in reducing addiction-related behavior and enhancing salience to social cues. We conducted a randomized, double-blind, placebo-controlled clinical trial of intranasal oxytocin administered twice daily for 6 weeks to male Veterans with stimulant use disorder who were also receiving opioid agonist therapy and counseling (n = 42). There was no significant effect of oxytocin on stimulant use, stimulant craving, or therapeutic alliance over 6 weeks. However, participants receiving oxytocin (vs. placebo) attended significantly more daily opioid agonist therapy dispensing visits. This replicated previous work suggesting that oxytocin may enhance treatment engagement among individuals with stimulant and opioid use disorders, which would address a significant barrier to effective care.