Clonidine Maintenance Prolongs Opioid Abstinence and Decouples Stress From Craving in Daily Life: A Randomized Controlled Trial With Ecological Momentary Assessment

The use of Experience Sampling Method in psychopharmacological studies: A systematic review

The Experience Sampling Method (ESM) is increasingly used to validate and assess treatment effects. We conducted a systematic review to update, and extend, the previous review by Bos et al. (2015), by performing literature searches in PubMed, PsycInfo, and EMBASE. Search queries included every DSM-disorder, ATC-listed psychotropic medication, and multiple search-terms for ESM. Studies included medicated psychiatric patients who filled-out ambulatory prompts ≥2/day. Templates served to distil research themes. The majority of the 79 included studies involved substance use- (n = 47), mood- (n = 17), and psychotic disorders (n = 11). Less studied were anxiety disorders and PTSD (n = 3), and ADHD (n = 1). We identified six research themes:1)Effects of psychopharmacological treatment on symptoms and factors influencing outcome, 2)Fluctuations of psychiatric symptoms in medicated patients, 3)Prediction of relapse, exacerbation of symptoms or medication non-compliance, 4)Added value of ESM compared to care as usual, 5)Using ESM to establish treatment response-trajectories, 6)Acceptability and feasibility of newly-devised ESM-applications. This review reveals that ESM is predominantly used in psychopharmacological studies to monitor treatment effects and establish fluctuations of momentary psychiatric symptoms. Future research might facilitate personalising psychopharmacological prescribing decisions using ESM. Currently underrepresented patient groups include elderly patients, and personality disorders. Finally, to facilitate ESM-implementation multiple context-levels should be optimised.

Effects of behavioral interventions on stress reactivity in adults with substance use disorders

OBJECTIVE

Heightened reactivity to stress is associated with poor treatment outcome in people with substance use disorders (SUDs). Behavioral strategies can reduce stress reactivity; however, these strategies are understudied in people with SUDs. The objective of this study was to test the effect of two behavioral strategies (cognitive reappraisal and affect labeling) on stress reactivity in people with SUDs.

METHOD

Treatment-seeking adults with SUDs (N = 119) were randomized to receive brief training in cognitive reappraisal, affect labeling, or a psychoeducational control, followed by a standardized stress induction. Markers of stress reactivity were collected before and following stress induction and included self-reported negative affect and substance craving, as well as salivary cortisol, and skin conductance response.

RESULTS

Analyses of covariance did not indicate a significant effect of treatment condition on negative affect, cortisol, or skin conductance response. Participants in the affect labeling condition had greater increase in craving than those in the cognitive reappraisal condition; neither condition differed from control.

CONCLUSIONS

Results indicated that, although participants were able to implement behavioral skills following a brief training, training condition did not modify stress reactivity, on average, relative to control. Future directions include consideration of individual differences in response to training and determination of whether higher "dosing" of skills via multiple sessions or extended practice is needed to influence stress reactivity in people with SUDs. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The Neurocircuitry of Substance Use Disorder, Treatment, and Change: A Resource for Clinical Psychiatrists

Substance use disorder (SUD) is common in psychiatric patients and has a negative impact on health and well-being. However, SUD often goes untreated, and there is a need for psychiatrists, of all specialties, to address this pervasive clinical problem. In this review, the authors' goal is to provide a resource that describes treatments for SUD, using neuroscience as a framework. They discuss the effect of pharmacotherapy on craving, intoxication, and withdrawal and its ability to interrupt the cycle of substance use in SUD. The neuroscience of stress is reviewed, including medications targeting neurotransmitter systems activated by alarm and fear. Neuroplasticity and promising treatments that use this mechanism, including ketamine, psilocybin, and transcranial magnetic stimulation (TMS), are discussed. The authors conclude by listing resources and practice guidelines for physicians interested in learning more about treatments for SUD.

Collaborating to heal addiction and mental health in primary care (CHAMP): A protocol for a hybrid type 2a trial

BACKGROUND

The gold-standard treatment for opioid use disorder (OUD) is medication for OUD (MOUD). However, less than a quarter of people with OUD initiate MOUD. Expanding the Collaborative Care Model (CoCM) to include primary care patients with OUD could improve access to and initiation of MOUD. This paper presents the methods and baseline sample characteristics of a Hybrid Type 2a trial comparing the effectiveness of CoCM for OUD and co-occurring mental health symptoms (MHS) to CoCM for MHS only.

METHOD

42 primary care clinics were cluster randomized and 254 primary care patients with OUD and elevated MHS were enrolled. Recruitment was terminated early by the Data and Safety Monitoring Board for futility. Participants completed research assessments at baseline, 3 months, and 6 months. The multiple primary outcomes were past-month number of days of nonmedical opioid use and SF12 Mental Health Component Summary (MCS) scores.

RESULTS

MCS scores were over a standard deviation below the national mean (M = 34.5). Nearly half (47.6 %) of participants had previously overdosed in their lifetimes. Three quarters (76.0 %) were already being prescribed MOUD at baseline, only 30.4 % reported non-medical use of opioids, and only 33.9 % reported being bothered by opioid cravings.

CONCLUSION

The unexpectedly high proportion of enrollees already prescribed MOUD at baseline indicates that most patients were in the maintenance rather than acute phase of treatment. Challenges identifying and enrolling patients in the acute phase of OUD treatment implies that intervention effectiveness will depend on its success preventing the discontinuation of MOUD rather than initiating MOUD.

Sex disparities in outcome of medication-assisted therapy of opioid use disorder: Nationally representative study

Question

The opioid epidemic causes massive morbidity, and males have substantially greater overdose mortality rates than females. It is unclear whether there are sex-related disparities at different stages in the trajectory of opioid use disorders, in "real world" settings.

Goal

To determine sex disparities in non-medical opioid use (NMOU) at the end of outpatient medication-assisted treatment (MAT), using nationally representative data.

Design

Observational epidemiological study of publicly funded outpatient MAT programs in the national "Treatment episode data set-discharges" (TEDS-D) for 2019.

Participants

Persons aged ≥18 in their first treatment episode, in outpatient MAT for use of heroin or other opioids (N=11,549). The binary outcome was presence/absence of NMOU.

Results

In univariate analyses, males had significantly higher odds of NMOU, compared to females (odds ratio=1.27; Chi2 [df:1]=39.08; uncorrected p<0.0001; p=0.0041 after Bonferroni correction). A multivariable logistic regression detected a male>female odds ratio of 1.19 (95%CI=1.09-1.29; p<0.0001), adjusting for socio-demographic/clinical variables. Several specific conditions were revealed in which males had greater odds of NMOU compared to females (e.g., at ages 18-29 and 30-39; corrected p=0.012, or if they used opioids by inhalation; corrected p=0.0041).

Conclusions

This nationally representative study indicates that males have greater odds of NMOU in their first episode of MAT, indicating more unfavorable outcomes. The study reveals specific socio-demographic and clinical variables under which this sex disparity is most prominent.

A historical perspective on clonidine as an alpha-2A receptor agonist in the treatment of addictive behaviors: Focus on opioid dependence

Clonidine operates through agonism at the alpha-2A receptor, a specific subtype of the alpha-2-adrenergic receptor located predominantly in the prefrontal cortex. By inhibiting the release of norepinephrine, which is responsible for withdrawal symptoms, clonidine effectively addresses withdrawal-related conditions such as anxiety, hypertension, and tachycardia. The groundbreaking work by Gold et al. demonstrated clonidine's ability to counteract the effects of locus coeruleus stimulation, reshaping the understanding of opioid withdrawal within the field. In the 1980s, the efficacy of clonidine in facilitating the transition to long-acting injectable naltrexone was confirmed for individuals motivated to overcome opioid use disorders (OUDs), including physicians and executives. Despite challenges with compliance, naltrexone offers sustained blockade of opioid receptors, reducing the risk of overdose, intoxication, and relapse in motivated patients in recovery. The development of clonidine and naltrexone as treatment modalities for OUDs, and potentially other addictions, including behavioral ones, underscores the potential for translating neurobiological advancements from preclinical models (bench) to clinical practice (bedside), ushering in innovative approaches to addiction treatment.

Psychological factors predicting patients' risk of relapse after enrollment in drug use treatment: A systematic review

BACKGROUND AND AIMS

Despite high rates of relapse after treatment for drug use, to our knowledge there is no systematic literature identifying psychological factors that predict risk of relapse to drug use (excluding alcohol or tobacco). Our aim was to identify psychological factors that predict risk of relapse to drug use after enrollment in drug use treatment. The identification of such factors can support treatment planning and relapse prevention.

METHODS

We searched for peer-reviewed articles published between 2000 and 2023 in PsycINFO, PsycArticles, Web of Science, and PubMed. The inclusion criteria were: peer-reviewed publications, quantitative studies, in English, adult samples, with a prospective design, and analyses of minimum one psychological factor as predictor of relapse to drug use. All authors were involved in abstract and full-text screening, and in assessing risk of bias. The findings are presented in a narrative synthesis and tables are organized by type of drug.

RESULTS

Of 2226 publications initially identified, 45 were eligible. Twenty-three focused on predicting relapse to stimulants, 15 to opioids, and 7 to unspecified drugs. Substance use at baseline was an important factor predicting risk of relapse to opioids, and possibly stimulants. There was an indication that craving and attention problems potentially predict relapse to use of some drugs. Mental health factors (e.g., psychiatric diagnosis) did not predict relapse. Several psychological factors (e.g., cognition, emotion, personality, motivation) were scarcely examined. Over half of the studies had moderate to high risk of bias.

CONCLUSIONS

Based on the 45 studies, few psychological factors predicted risk of relapse to drug use. Higher comparability between studies and more rigorous methodology are necessary in order to derive more precise recommendations that inform and improve clinical practice.

PRE-REGISTRATION

PROSPERO, CRD42020182839.

Opioid craving does not incubate over time in inpatient or outpatient treatment studies: Is the preclinical incubation of craving model lost in translation?

Within addiction science, incubation of craving is an operational label used to describe time-dependent increases in drug seeking during periods of drug deprivation. The purpose of this systematic review was to describe the preclinical literature on incubation of craving and the clinical literature on craving measured over extended periods of abstinence to document this translational homology and factors impacting correspondence. Across the 44 preclinical studies that met inclusion criteria, 31 reported evidence of greater lever pressing, nose pokes, spout licks, or time spent in drug-paired compartments (i.e., drug seeking) relative to neutral compartments after longer periods of abstinence relative to shorter periods of abstinence, labelled as "incubation of craving." In contrast, no clinical studies (n = 20) identified an increase in opioid craving during longer abstinence periods. The lack of clinical evidence for increases in craving in clinical populations weakens the translational utility of operationalizing the time-dependent increase in drug-seeking behavior observed in preclinical models as models of incubation of "craving".

Individual-Level Risk Prediction of Return to Use During Opioid Use Disorder Treatment

Importance

No existing model allows clinicians to predict whether patients might return to opioid use in the early stages of treatment for opioid use disorder.

Objective

To develop an individual-level prediction tool for risk of return to use in opioid use disorder.

Design, Setting, and Participants

This decision analytical model used predictive modeling with individual-level data harmonized in June 1, 2019, to October 1, 2022, from 3 multicenter, pragmatic, randomized clinical trials of at least 12 weeks' duration within the National Institute on Drug Abuse Clinical Trials Network (CTN) performed between 2006 and 2016. The clinical trials covered a variety of treatment settings, including federally licensed treatment sites, physician practices, and inpatient treatment facilities. All 3 trials enrolled adult participants older than 18 years, with broad pragmatic inclusion and few exclusion criteria except for major medical and unstable psychiatric comorbidities.

Intervention

All participants received 1 of 3 medications for opioid use disorder: methadone, buprenorphine, or extended-release naltrexone.

Main Outcomes and Measures

Predictive models were developed for return to use, which was defined as 4 consecutive weeks of urine drug screen (UDS) results either missing or positive for nonprescribed opioids by week 12 of treatment.

Results

The overall sample included 2199 trial participants (mean [SD] age, 35.3 [10.7] years; 728 women [33.1%] and 1471 men [66.9%]). The final model based on 4 predictors at treatment entry (heroin use days, morphine- and cocaine-positive UDS results, and heroin injection in the past 30 days) yielded an area under the receiver operating characteristic curve (AUROC) of 0.67 (95% CI, 0.62-0.71). Adding UDS in the first 3 treatment weeks improved model performance (AUROC, 0.82; 95% CI, 0.78-0.85). A simplified score (CTN-0094 OUD Return-to-Use Risk Score) provided good clinical risk stratification wherein patients with weekly opioid-negative UDS results in the 3 weeks after treatment initiation had a 13% risk of return to use compared with 85% for those with 3 weeks of opioid-positive or missing UDS results (AUROC, 0.80; 95% CI, 0.76-0.84).

Conclusions and Relevance

The prediction model described in this study may be a universal risk measure for return to opioid use by treatment week 3. Interventions to prevent return to regular use should focus on this critical early treatment period.

Therapeutics for Substance-Using Women: The Need to Elucidate Sex-Specific Targets for Better-Tailored Treatments

In the last decade, alcohol consumption in the US has risen by 84% in women compared with 35% in men. Furthermore, research has shown that sex- and gender-related differences may disadvantage women in terms of developing a range of psychological, cognitive, and medical problems considerably earlier in their drinking history than men, and despite consuming a similar quantity of substances. While this "telescoping" process has been acknowledged in the literature, a concomitant understanding of the underlying biobehavioral mechanisms, and an increase in the development of specific treatments tailored to women, has not occurred. In the current chapter we focus on understanding why the need for personalized, sex-specific medications is imperative, and highlight some of the potential sex-specific gonadal and stress-related adaptations underpinning the accelerated progress from controlled to compulsive drug and alcohol seeking in women. We additionally discuss the efficacy of these mechanisms as novel targets for medications development, using exogenous progesterone and guanfacine as examples. Finally, we assess some of the challenges faced and progress made in terms of developing innovative medications in women. We suggest that agents such as exogenous progesterone and adrenergic medications, such as guanfacine, may provide some efficacy in terms of attenuating stress-induced craving for several substances, as well as improving the ability to emotionally regulate in the face of stress, preferentially in women. However, to fully leverage the potential of these therapeutics in substance-using women, greater focus needs to the placed on reducing barriers to treatment and research by encouraging women into clinical trials.

Alleviation of opioid withdrawal by cannabis and delta-9-tetrahydrocannabinol: A systematic review of observational and experimental human studies

BACKGROUND

While six U.S. states have already officially authorized cannabinoids to substitute opioids and treat opioid use disorder, the therapeutic benefits of cannabinoids remain unclear, especially when weighted against their adverse effects.

METHODS

We conducted a systematic review of studies examining the association between opioid withdrawal and cannabis use or delta-9-tetrahydrocannabinol (THC) administration. We searched multiple databases from inception to July 30, 2022, and assessed study quality.

RESULTS

Eleven studies were identified, with a total of 5330 participants, of whom 64 % were male. Nine observational studies examined the association between cannabis use and opioid withdrawal. Two randomized, placebo-controlled clinical trials (RCTs) investigated the withdrawal-alleviating effects of dronabinol, a synthetic form of THC. Four observational studies found an association between cannabis use and the alleviation of opioid withdrawal; one reported exacerbation of opioid withdrawal symptoms; and four reported no association. RCTs reported that THC alleviated opioid withdrawal, albeit with dose-dependent increases in measures of abuse liability, dysphoria, and tachycardia. There was high heterogeneity in measurements of opioid withdrawal and the type and dose of opioid at baseline.

CONCLUSIONS

Although there is preliminary evidence that cannabis and its main psychoactive constituent, THC, may alleviate opioid withdrawal, these effects are likely to have a narrow therapeutic window. Further, the potential of cannabinoids to alleviate opioid withdrawal is determined by complex interactions between patient characteristics and pharmacological factors. Collectively, these findings have clinical, methodological, and mechanistic implications for treating opioid withdrawal during cannabinoid use, and for efforts to alleviate opioid withdrawal using non-opioid therapeutics.

Prefrontal cortical response to natural rewards and self-reported anhedonia are associated with greater craving among recently withdrawn patients in residential treatment for opioid use disorder

Both anhedonia and craving are common among patients with opioid use disorder (OUD), and are associated with vulnerability to relapse. Although these constructs are theoretically linked relatively few studies have examined them together. In the current study, recently withdrawn patients (N = 71) in residential treatment for prescription OUD underwent a cue reactivity paradigm while being monitored with functional near-infrared spectroscopy (fNIRS). Patients also self-reported symptoms of anhedonia via the Snaith-Hamilton Pleasure Scale (SHAPS), while smartphone-based ecological momentary assessments (EMA) were used to measure craving levels. On average, lower right prefrontal cortex (PFC) activity in response to positive social stimuli was associated with higher craving (β = - 2.87; S.E. = 1.23; p = 0.02). Self-reported anhedonia moderated the association between PFC activity and craving (β = - 1.02; S.E. = 0.48; p = 0.04), such that patients with two or more anhedonic symptoms had a significant and stronger negative association between PFC activation to hedonically positive images and craving, compared to patients with fewer than two anhedonic symptoms, among whom the association was not significant. This finding provides evidence that higher levels of anhedonia among patients in residential treatment for OUD are associated with a stronger link between lower PFC response to positive social experiences and higher levels of craving, potentially increasing overall vulnerability to relapse.

Mechanism of opioid addiction and its intervention therapy: Focusing on the reward circuitry and mu-opioid receptor

Opioid abuse and addiction have become a global pandemic, posing tremendous health and social burdens. The rewarding effects and the occurrence of withdrawal symptoms are the two mainstays of opioid addiction. Mu-opioid receptors (MORs), a member of opioid receptors, play important roles in opioid addiction, mediating both the rewarding effects of opioids and opioid withdrawal syndrome (OWS). The underlying mechanism of MOR-mediated opioid rewarding effects and withdrawal syndrome is of vital importance to understand the nature of opioid addiction and also provides theoretical basis for targeting MORs to treat drug addiction. In this review, we first briefly introduce the basic concepts of MORs, including their structure, distribution in the nervous system, endogenous ligands, and functional characteristics. We focused on the brain circuitry and molecular mechanism of MORs-mediated opioid reward and withdrawal. The neuroanatomical and functional elements of the neural circuitry of the reward system underlying opioid addiction were thoroughly discussed, and the roles of MOR within the reward circuitry were also elaborated. Furthermore, we interrogated the roles of MORs in OWS, along with the structural basis and molecular adaptions of MORs-mediated withdrawal syndrome. Finally, current treatment strategies for opioid addiction targeting MORs were also presented.

Consideration of sex and gender differences in addiction medication response

Substance use continues to contribute to significant morbidity and mortality in the United States, for both women and men, more so than another other preventable health condition. To reduce the public health burden attributable to substances, the National Institute on Drug Abuse and the National Institute on Alcohol Abuse and Alcoholism have identified that medication development for substance use disorder is a high priority research area. Furthermore, both Institutes have stated that research on sex and gender differences in substance use medication development is a critical area. The purpose of the current narrative review is to highlight how sex and gender have been considered (or not) in medication trials for substance use disorders to clarify and summarize what is known regarding sex and gender differences in efficacy and to provide direction to the field to advance medication development that is consistent with current NIH 'sex as a biological variable' (SABV) policy. To that end, we reviewed major classes of abused substances (nicotine, alcohol, cocaine, cannabis, opioids) demonstrating that, sex and gender have not been well-considered in addiction medication development research. However, when adequate data on sex and gender differences have been evaluated (i.e., in tobacco cessation), clinically significant differences in response have been identified between women and men. Across the other drugs of abuse reviewed, data also suggest sex and gender may be predictive of outcome for some agents, although the relatively low representation of women in clinical research samples limits making definitive conclusions. We recommend the incorporation of sex and gender into clinical care guidelines and improved access to publicly available sex-stratified data from medication development investigations.

Logical fallacies and misinterpretations that hinder progress in translational addiction neuroscience

Substance use disorders (SUDs) are heterogeneous and complex, making the development of translationally predictive rodent and nonhuman primate models to uncover their neurobehavioral underpinnings difficult. Neuroscience-focused outcomes have become highly prevalent, and with this, the notion that SUDs are disorders of the brain embraced as a dominant theoretical orientation to understand SUD etiology and treatment. These efforts, however, have led to few efficacious pharmacotherapies, and in some cases (as with cocaine or methamphetamine), no pharmacotherapies have translated from preclinical models for clinical use. In this theoretical commentary, we first describe the development of animal models of substance use behaviors from a historical perspective. We then define and discuss three logical fallacies including 1) circular explanation, 2) affirming the consequent, and 3) reification that can apply to developed models. We then provide three case examples in which conceptual or logical issues exist in common methods (i.e., behavioral economic demand, escalation, and reinstatement). Alternative strategies to refocus behavioral models are suggested for the field to better bridge the translational divide between animal models, the clinical condition of SUDs, and current and future regulatory pathways for intervention development.

The impact of lofexidine on stress-related opioid craving and relapse: Design and methodology of a randomized clinical trial

Opioid Use Disorders (OUDs) and drug overdose deaths are increasing at alarmingly high rates in the United States. Stress and dysregulation in biologic stress response systems such as the hypothalamic-pituitary-adrenal axis and noradrenergic system appear to play an important role in the pathophysiology of substance use disorders and relapse to drug use, particularly for women. Alpha-2 adrenergic agonist medications effectively decrease noradrenergic activity and have demonstrated benefit in preventing relapse to substance use and decreasing stress-reactivity and craving in cocaine- and nicotine-dependent women, compared to men. Alpha-2 adrenergic agonists may help decrease stress reactivity in individuals with OUDs and prevent relapse to drug use, but gender differences have yet to be systematically explored. We describe the rationale, study design and methodology of a randomized, double-blind, placebo-controlled clinical trial examining gender differences in stress, craving and drug use among adult men and women with OUD taking methadone or buprenorphine and randomly assigned to an alpha-2 adrenergic agonist, lofexidine, compared to placebo. In addition, we describe methods for measuring daily stress, craving and drug use in participant's natural environment as well as participant's physiological (i.e., heart rate, cortisol) and psychological (i.e., stress, craving) response to laboratory social and drug cue stressors. Lastly, we detail methods adopted to sustain research activity while following guidelines for the COVID-19 pandemic. ClinicalTrials.gov Registration Number: NCT03718065.

Laboratory-induced stress and craving predict opioid use during follow-up among individuals with prescription opioid use disorder

BACKGROUND

Opioid use disorder (OUD) remains a public health crisis in the USA. Although stress and craving are common precipitants of substance use, no research to date has investigated the impact of laboratory-induced stress and craving on subsequent opioid use.

METHOD

Participants (N = 31) were individuals with prescription OUD who completed a human laboratory study followed by a one-month follow-up visit. Participants were randomly assigned to either a stress task (i.e., Trier Social Tress Task; TSST) or a no-stress condition, and then all participants completed an opioid cue paradigm. Measures of subjective (e.g., stress, craving), and neuroendocrine (e.g., cortisol, dehydroepiandrosterone) reactivity were assessed before and after each task. Survival and regression models tested the association between reactivity to the laboratory tasks and a) time to first opioid use and b) amount of opioid use during follow-up.

RESULTS

On average, participants first used opioids 3.65 (SD = 2.08) days following the study. Craving after the opioid cue paradigm (B = 0.44, Exp(B) = 1.55, 95 % CI [1.06, 2.28], p = .02) and after the TSST/no-stress condition plus opioid cue paradigm (B = 1.06, Exp(B) = 2.88, 95 % CI [1.70, 4.85], p < .001) predicted time to first use. Additionally, there was a significant interaction between randomization to the TSST, stress reactivity, and amount of opioids used.

CONCLUSIONS

Findings demonstrate that elevated cue-induced craving, either in the context of a stressor or not, is associated with shortened time to opioid use, whereas stress reactivity impacts the amount of opioids consumed. Preliminary findings add to the literature on stress, craving and opioid use and implicate treatment.

Consideration of sex as a biological variable in the translation of pharmacotherapy for stress-associated drug seeking

Stress is a frequent precipitant of relapse to drug use. Pharmacotherapies targeting a diverse array of neural systems have been assayed for efficacy in attenuating stress-induced drug-seeking in both rodents and in humans, but none have shown enough evidence of utility to warrant routine use in the clinic. We posit that a critical barrier in effective translation is inattention to sex as a biological variable at all phases of the research process. In this review, we detail the neurobiological systems implicated in stress-induced relapse to cocaine, opioids, methamphetamine, and cannabis, as well as the pharmacotherapies that have been used to target these systems in rodent models, the human laboratory, and in clinical trials. In each of these areas we additionally describe the potential influences of biological sex on outcomes, and how inattention to fundamental sex differences can lead to biases during drug development that contribute to the limited success of large clinical trials. Based on these observations, we determine that of the pharmacotherapies discussed only α₂-adrenergic receptor agonists and oxytocin have a body of research with sufficient consideration of biological sex to warrant further clinical evaluation. Pharmacotherapies that target β-adrenergic receptors, other neuroactive peptides, the hypothalamic-pituitary-adrenal axis, neuroactive steroids, and the endogenous opioid and cannabinoid systems require further assessment in females at the preclinical and human laboratory levels before progression to clinical trials can be recommended.

Animal Models of Drug Relapse and Craving after Voluntary Abstinence: A Review

Relapse to drug use during abstinence is a defining feature of addiction. During the last several decades, this clinical scenario has been studied at the preclinical level using classic relapse/reinstatement models in which drug seeking is assessed after experimenter-imposed home-cage forced abstinence or extinction of the drug-reinforced responding in the self-administration chambers. To date, however, results from studies using rat relapse/reinstatement models have yet to result in Food and Drug Administration-approved medications for relapse prevention. The reasons for this state of affairs are complex and multifaceted, but one potential reason is that, in humans, abstinence is often self-imposed or voluntary and occurs either because the negative consequences of drug use outweigh the drug's rewarding effects or because of the availability of nondrug alternative rewards that are chosen over the drug. Based on these considerations, we and others have recently developed rat models of relapse after voluntary abstinence, achieved either by introducing adverse consequences to drug taking (punishment) or seeking (electric barrier) or by providing mutually exclusive choices between the self-administered drug and nondrug rewards (palatable food or social interaction). In this review, we provide an overview of these translationally relevant relapse models and discuss recent neuropharmacological findings from studies using these models. We also discuss sex as a biological variable, future directions, and clinical implications of results from relapse studies using voluntary abstinence models. Our main conclusion is that the neuropharmacological mechanisms controlling relapse to drug seeking after voluntary abstinence are often different from the mechanisms controlling relapse after home-cage forced abstinence or reinstatement after extinction. SIGNIFICANCE STATEMENT: This review describes recently developed rat models of relapse after voluntary abstinence, achieved either by introducing adverse consequences to drug taking or seeking or by providing mutually exclusive choices between the self-administered drug and nondrug rewards. This review discusses recent neuropharmacological findings from studies using these models and discusses future directions and clinical implications.

Pharmacological treatment of pain among persons with opioid addiction: A systematic review and meta-analysis with implications for drug development

The clinical features and neurobiology of pain and opioid use disorder (OUD) are inextricably linked. Despite emerging evidence supporting the negative impact of ongoing pain in the treatment of OUD, the pharmacological management of pain in the presence of OUD has received limited attention. We sought to systematically review the studies investigating pharmacotherapies for pain among persons with OUD. Eligible studies had participants with OUD and outcomes including evoked or spontaneous pain. We searched Scopus, Cochrane Database of Systematic Reviews, Medline, and Embase. Out of 1,097 studies that met the search criteria, 12 studies provided data relevant to the research question-five laboratory studies and seven clinical trials. Random effects pooled estimates suggested no significant difference between groups at baseline but a response favoring the active treatment group over placebo, with nonsignificant heterogeneity between studies. Findings from these studies provide preliminary evidence for analgesic and antihyperalgesic effects of gabapentin, GABA agonists, and NMDA antagonists among persons with OUD. To establish the tradeoffs between the analgesic effects and abuse liability of these compounds, further well-controlled clinical trials are required among persons with OUD. This review also underscores the need for methodological enhancement in drug development for pain in OUD. Future research should address the clinical and neurobiological overlap between pain- and addiction-related phenomena. Transdisciplinary approaches may identify biomarkers of these shared phenomena and their neural substrates. The development of novel therapeutics for pain in OUD may be accelerated by such integration of pain and addiction research.

Drug addiction co-morbidity with alcohol: Neurobiological insights

Addiction is a chronic disorder that consists of a three-stage cycle of binge/intoxication, withdrawal/negative affect, and preoccupation/anticipation. These stages involve, respectively, neuroadaptations in brain circuits involved in incentive salience and habit formation, stress surfeit and reward deficit, and executive function. Much research on addiction focuses on the neurobiology underlying single drug use. However, alcohol use disorder (AUD) can be co-morbid with substance use disorder (SUD), called dual dependence. The limited epidemiological data on dual dependence indicates that there is a large population of individuals suffering from addiction who are dependent on more than one drug and/or alcohol, yet dual dependence remains understudied in addiction research. Here, we review neurobiological data on neurotransmitter and neuropeptide systems that are known to contribute to addiction pathology and how the involvement of these systems is consistent or divergent across drug classes. In particular, we highlight the dopamine, opioid, corticotropin-releasing factor, norepinephrine, hypocretin/orexin, glucocorticoid, neuroimmune signaling, endocannabinoid, glutamate, and GABA systems. We also discuss the limited research on these systems in dual dependence. Collectively, these studies demonstrate that the use of multiple drugs can produce neuroadaptations that are distinct from single drug use. Further investigation into the neurobiology of dual dependence is necessary to develop effective treatments for addiction to multiple drugs.

Medications Development for Treatment of Opioid Use Disorder

This review describes methods for preclinical evaluation of candidate medications to treat opioid use disorder (OUD). The review is founded on the propositions that (1) drug self-administration procedures provide the most direct method for assessment of medication effectiveness, (2) procedures that assess choice between opioid and nondrug reinforcers are especially useful, and (3) states of opioid dependence and withdrawal profoundly influence both opioid reinforcement and effects of candidate medications. Effects of opioid medications and vaccines on opioid choice in nondependent and opioid-dependent subjects are reviewed. Various nonopioid medications have also been examined, but none yet have been identified that safely and reliably reduce opioid choice. Future research will focus on (1) strategies for increasing safety and/or effectiveness of opioid medications (e.g., G-protein-biased μ-opioid agonists), and (2) continued development of nonopioid medications (e.g., clonidine) that might serve as adjunctive agents to current opioid medications.

Ambulatory Assessment Methods to Examine Momentary State-Based Predictors of Opioid Use Behaviors

PURPOSE OF REVIEW

Addiction scientists have begun using ambulatory assessment methods-including ecological momentary assessment (EMA), experience sampling, and daily diaries-to collect real-time or near-real-time reports of participants' internal states in their natural environments. The goal of this short review is to synthesize EMA findings from our research group, which has studied several hundred outpatients during treatment for opioid-use disorder (OUD). (We cite pertinent findings from other groups, but have not tried to be comprehensive.) One of our main goals in using EMA is to examine momentary changes in internal states that proximally predict, or concurrently mark, events such as lapses to opioid use.

RECENT FINDINGS

We summarize findings evaluating several classes of momentary markers or predictors (craving, stress, negative and positive moods, and physical pain/discomfort) of lapses and other states/behaviors. Craving and some negatively valenced mood states are concurrently and prospectively associated with lapses to opioid use during treatment. Craving is also concurrently and prospectively associated with momentary changes in stress and mood. Convincing evidence has not yet emerged for stress as a robust redictor of lapse to opioid use; it appears to be contributory, but neither necessary nor sufficient.

SUMMARY

Ambulatory assessment can capture changes in internal states and drug-related behaviors in situ and at high temporal resolution. We recommend research strategies that may increase the clinical and prognostic utility of ambulatory assessment, including denser sampling (i.e., more assessments per day) and more attention to heterogeneity across people and across populations.

Feasibility and Preliminary Efficacy of Isradipine During Outpatient Buprenorphine Stabilization and Detoxification: A Pilot Randomized, Placebo-Controlled Trial

Background:

Given the immense burden of the widespread use of opioids around the world, exploring treatments that improve drug use outcomes, and craving and withdrawal measures in individuals with opioid use disorder is crucial. This pilot study examined the feasibility and preliminary efficacy of the L-type calcium-channel blocker isradipine (ISR) to improve drug use outcomes, and craving and withdrawal measures during buprenorphine (BUP)/ISR stabilization and subsequent taper in opioid-dependent individuals.

Methods:

Participants were stabilized on BUP sublingual tablets within the first 2 days of week 1, were then randomized and inducted on either ISR or placebo, gradually increasing the dose over the next 2 weeks, followed by a 10-day BUP taper during weeks 5-6, and ISR/placebo taper during weeks 7 to 8. Assessments included thrice-weekly measures of craving and withdrawal, as well as vital signs and urine drug screens. Medication compliance was assessed by monitoring number of missed clinic visit days.

Results:

Baseline characteristics of participants (n = 25; 60% male, 96% Caucasian, 48% employed, mean age 32.8 years) did not differ significantly between treatment groups (isradipine, n = 11; placebo, n = 14). During the stabilization phase (n = 19), ISR participants had significantly lower rates of illicit opioid-positive urines (treatment × visit: t = -2.16, P = 0.03), as well as reduction in craving intensity (t = –2.50, P = 0.01), frequency (t = –3.43, P < 0.01) and duration (t = –2.51, P = 0.01). ISR was well tolerated with mild adverse effects.

Conclusions:

This study was likely underpowered due to being a pilot trial. Although preliminary results suggest ISR may improve BUP-assisted treatment outcomes, concerns about high number of exclusions (n = 11 during taper phase) based on cardiovascular measures as well as ISR-induced changes in vital signs with the immediate release formulation may limit the feasibility of this approach.

Trial Registration:

Clinicaltrials.gov identifier NCT01895270. Registered 10 July 2013, https://clinicaltrials.gov/ct2/show/NCT01895270?id=NCT01895270&draw=2&rank=1

Improving translation of animal models of addiction and relapse by reverse translation

Critical features of human addiction are increasingly being incorporated into complementary animal models, including escalation of drug intake, punished drug seeking and taking, intermittent drug access, choice between drug and non-drug rewards, and assessment of individual differences based on criteria in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Combined with new technologies, these models advanced our understanding of brain mechanisms of drug self-administration and relapse, but these mechanistic gains have not led to improvements in addiction treatment. This problem is not unique to addiction neuroscience, but it is an increasing source of disappointment and calls to regroup. Here we first summarize behavioural and neurobiological results from the animal models mentioned above. We then propose a reverse translational approach, whose goal is to develop models that mimic successful treatments: opioid agonist maintenance, contingency management and the community-reinforcement approach. These reverse-translated 'treatments' may provide an ecologically relevant platform from which to discover new circuits, test new medications and improve translation.

Behavioral strategies to reduce stress reactivity in opioid use disorder: Study design

OBJECTIVES

More than 2 million people in the United States had an opioid use disorder in 2017. Treatment for opioid use disorder-particularly medication combined with psychosocial support-is effective for reducing opioid use and decreasing overdose risk. However, approximately 50% of people who receive treatment will relapse or drop out. Stress reactivity, defined as the subjective and physiological response to stress, is heightened in people with opioid use disorder and higher stress reactivity is associated with poorer outcomes. Preliminary studies suggest that stress reactivity may be a key mechanistic target for improving outcomes. This article describes the design of an ongoing study examining behavioral strategies for reducing stress reactivity in adults with opioid use disorder. Our objective is to test the efficacy of two behavioral strategies for reducing stress reactivity and enhancing behavioral persistence in the context of stress (distress tolerance).

METHOD

We will recruit 120 adults with opioid use disorder and randomly assign them to brief training in (a) cognitive reappraisal, (b) affect labeling, or (c) a psychoeducational control. Participants will receive the training intervention followed by a laboratory stressor during which they will be instructed to apply the trained skill.

RESULTS

Subjective and physiological responses to stress will be measured as indices of stress reactivity and the stressor task will include a behavioral persistence component as a measure of distress tolerance.

CONCLUSIONS

The ultimate goal of this study is to inform the development of behavioral interventions that can be used as an adjunct to medication-based treatment for opioid use disorder. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

The Influence of Co-Occurring Substance Use on the Effectiveness of Opiate Treatment Programs According to Intervention Type

This systematic review describes the influence of co-occurring substance use on the effectiveness of opiate treatment programs. MEDLINE/PubMed, Embase, PsychINFO, and the Cumulative Index to Nursing and Allied Health Literature were searched from database inception to November 28, 2018, to identify eligible opioid treatment studies in the United States that assessed the relationship between co-occurring substance use and treatment outcome (i.e., opioid abstinence and treatment retention). A total of 34 eligible studies were included. Overall, co-occurring substance use was associated with negative treatment outcomes regardless of intervention type. However, patterns varied by substance and intervention type. In particular, co-occurring use of cocaine or marijuana with opioids was associated with reduced treatment retention and opioid abstinence regardless of intervention type. Co-occurring use of amphetamines, compared with no use or reduced use of amphetamines, decreased treatment retention. Co-occurring use of alcohol was both positively and negatively associated with treatment outcomes. One study reported a significant positive association between sedative use and opioid abstinence. Generally, findings suggest that combined interventions reported better health outcomes compared with pharmacological or behavioral intervention studies alone. The findings of this review emphasize the need to comprehensively study and address co-occurring substance use to improve opiate treatment programs.

Safety and Efficacy of Lofexidine for Medically Managed Opioid Withdrawal: A Randomized Controlled Clinical Trial

Supplemental Digital Content is available in the text

Objectives:

To investigate the safety and efficacy of lofexidine for treating opioid withdrawal syndrome (OWS) and facilitating completion of opioid withdrawal.

Methods:

A multicenter, double-blind, placebo-controlled study was conducted at 18 US centers from June 2013 to December 2014. Participants (n = 603) aged ≥18 years, dependent on short-acting opioids, and seeking withdrawal treatment, randomized 3:3:2 to receive lofexidine 2.88 mg/d (n = 222), lofexidine 2.16 mg/d (n = 230), or placebo (n = 151) for 7 days. Primary outcome was the Short Opiate Withdrawal Scale of Gossop (SOWS-Gossop) scores rating withdrawal symptoms over days 1 to 7.

Results:

Participants were of mean age, 35 years; 71% male. Pairwise differences in overall SOWS-Gossop log-transformed least squares means were statistically significant for lofexidine 2.16 mg (difference, −0.21; 95% CI, −0.37 to −0.04; P = 0.02) and 2.88 mg (−0.26; 95% CI, −0.44 to −0.09; P = 0.003) compared with placebo. Fewer than half of participants in both groups completed the study. Completion rates for lofexidine 2.16 mg (41.5%; odds ratio [OR], 1.85; P = 0.007) and 2.88 mg (39.6%; OR, 1.71; P = 0.02) were significantly better compared with placebo (27.8%). Overall adverse event (AE) rates were similar across groups. Common AEs for lofexidine included orthostatic hypotension, hypotension, and bradycardia, but resulted in few study discontinuations.

Conclusions:

Lofexidine 2.16 mg and 2.88 mg significantly reduced symptoms of OWS versus placebo, and increased absolute rates of completing the 7-day study by 14% and 12%, respectively (a relative increase of 85% and 71%). Data suggest that lofexidine is a generally safe and effective nonopioid treatment for opioid withdrawal. Lofexidine could serve as a withdrawal treatment option when a nonopioid agent is preferred or required, when agonist-assisted withdrawal is unavailable, when agonist discontinuation caused OWS, and during induction into maintenance treatment with opioid agonists or antagonists.

Trial Registration:

ClinicalTrials.gov identifier: NCT01863186.

Update on the Neuropsychiatry of Substance Use Disorders

This article reviews some of the recent discoveries about how neurobiological processes contribute to the understanding and treatment of substance use disorders. Particular focus is given to cannabis, opioids, and designer drugs. Important areas addressed include triggers and cravings, the central roles of dopamine and stress, and the endocannabinoid system. Clinical relevance of these findings for withdrawal management and relapse prevention is discussed. Also highlighted are issues related to the opioid epidemic and consequences both of continuing federal prohibition of cannabis as well as its state-by-state relaxation.

Assessment of Co-Occurring Substance Use During Opiate Treatment Programs in the United States

The effectiveness of opiate treatment programs (OTPs) can be significantly influenced by co-occurring substance use, yet there are no standardized guidelines for assessing the influence of co-occurring substance use on treatment outcomes. In this review, we aim to provide an overview on the status of the assessment of co-occurring substance use during participation in OTPs in the United States. We searched 4 databases-MEDLINE/PubMed, EMBASE, PsychINFO, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL)-from database inception to November 2018 to select relevant publications on OTPs that assessed participants' co-occurring substance use. We used a standardized protocol to extract study, intervention, and co-occurring substance use characteristics. Methodological quality was assessed using the Quality in Prognosis Studies tool. Of the 3,219 titles screened, 614 abstracts and 191 full-text original publications were assessed, leaving 85 eligible articles. Co-occurring substance use was most often assessed during opioid treatments using combined (pharmacological and behavioral) (n = 57 studies) and pharmacological (n = 25 studies) interventions. Cocaine, alcohol, marijuana, and benzodiazepines were frequently measured, while amphetamines and tobacco were rarely assessed. Great variation existed between studies in the timing and measurement of co-occurring substance use, as well as definitions for substances and polysubstance/polydrug use. Inconsistencies in the investigation of co-occurring substance use make comparison of results across studies challenging. Standardized measures and consensus on research on co-occurring substance use is needed to produce the evidence required to develop personalized treatment programs for persons using multiple substances and to inform best-practice guidelines for addressing polydrug use during participation in OTPs.

Opioid withdrawal symptoms, a consequence of chronic opioid use and opioid use disorder: Current understanding and approaches to management

WHAT IS KNOWN AND OBJECTIVE

Opioid use in the United States has reached unprecedented-some would even say crisis-levels. Although many individuals use opioid drugs as part of legitimate pain management plans, a significant number misuse prescription or illicit opioids. With regular opioid use, individuals develop tolerance and physical dependence; both are predictable, physiologic responses to repeated opioid exposure. However, a substantial number of individuals who misuse opioids will develop opioid use disorder (OUD), a complex, primary, chronic, neurobiological disease rooted in genetic, environmental and psychosocial factors. This article discusses OUD, opioid receptor physiology, and opioid withdrawal symptomatology and pathophysiology, as well as current treatment options available to reduce opioid withdrawal symptoms in individuals with physical dependence and/or OUD.

METHODS

The research articles regarding OUD and its management have been reviewed thoroughly based on a PubMed literature search using keywords related to opioid dependence, its pathophysiology and current treatment strategies.

RESULTS AND DISCUSSION

Tolerance/physical dependence and the behavioural characteristics associated with OUD reflect complex neurobiologic adaptations in several major systems of the brain, including the locus ceruleus and mesolimbic systems. Physical dependence is responsible for the distressing withdrawal symptoms individuals experience upon abrupt cessation or rapid dose reduction of exogenous opioids. Opioid withdrawal symptoms are a key driver behind continued opioid use, and a barrier to opioid discontinuation. Several opioid-based medications are available to treat patients with OUD; these treatments can diminish opioid withdrawal symptoms and cravings as well as block opioid effects in the event of relapse. Additionally, non-opioid drugs may be used during acute detoxification to help alleviate opioid withdrawal symptoms.

WHAT IS NEW AND CONCLUSION

The opioid crisis has produced many challenges for physicians, one being the need to determine which patients would benefit most from maintenance therapy and which may be candidates for opioid discontinuation. In addition to summarizing current understanding of OUD, we provide a new algorithm for determining the need for continued opioid use as well as examples of situations where management of opioid withdrawal symptoms is indicated.

Craving and opioid use disorder: A scoping review

INTRODUCTION

The subjective experience of drug craving is a prominent and common clinical phenomenon for many individuals diagnosed with opioid use disorder (OUD), and could be a valuable clinical endpoint in medication development studies. The purpose of this scoping review is to provide an overview and critical analysis of opioid craving assessments located in the published literature examining OUD.

METHOD

Studies were identified through a search of PubMed, Embase, and PsychInfo databases and included for review if opioid craving was the focus and participants were diagnosed with or in treatment for OUD.

RESULTS

Fifteen opioid craving assessment instruments were identified across the 87 studies included for review. The most common were the Visual Analog Scale (VAS, 41 studies), Desires for Drug Questionnaire (DDQ, 12 studies), Heroin Craving Questionnaire (HCQ, 10 studies), and Obsessive-Compulsive Drug Use Scale (OCDUS, 10 studies). Craving assessments varied considerably in their format, content, time frame, and underlying subscales, and only 6 of 15 had been psychometrically evaluated.

DISCUSSION

This review identified a variety of opioid craving assessments, but few had been evaluated for their psychometric properties making it difficult to ascertain whether craving is being assessed optimally in studies of OUD. Thus, the development of a reliable and valid opioid craving assessment would be worthwhile and could be guided by recently published Food and Drug Administration Clinical Outcome Assessment (COA) guidelines. Importantly, a COA focused on opioid craving could be a valuable addition to research studies designed to evaluate novel treatments for OUD.

Understanding Addiction Using Animal Models

Drug addiction is a neuropsychiatric disorder with grave personal consequences that has an extraordinary global economic impact. Despite decades of research, the options available to treat addiction are often ineffective because our rudimentary understanding of drug-induced pathology in brain circuits and synaptic physiology inhibits the rational design of successful therapies. This understanding will arise first from animal models of addiction where experimentation at the level of circuits and molecular biology is possible. We will review the most common preclinical models of addictive behavior and discuss the advantages and disadvantages of each. This includes non-contingent models in which animals are passively exposed to rewarding substances, as well as widely used contingent models such as drug self-administration and relapse. For the latter, we elaborate on the different ways of mimicking craving and relapse, which include using acute stress, drug administration or exposure to cues and contexts previously paired with drug self-administration. We further describe paradigms where drug-taking is challenged by alternative rewards, such as appetitive foods or social interaction. In an attempt to better model the individual vulnerability to drug abuse that characterizes human addiction, the field has also established preclinical paradigms in which drug-induced behaviors are ranked by various criteria of drug use in the presence of negative consequences. Separation of more vulnerable animals according to these criteria, along with other innate predispositions including goal- or sign-tracking, sensation-seeking behavior or impulsivity, has established individual genetic susceptibilities to developing drug addiction and relapse vulnerability. We further examine current models of behavioral addictions such as gambling, a disorder included in the DSM-5, and exercise, mentioned in the DSM-5 but not included yet due to insufficient peer-reviewed evidence. Finally, after reviewing the face validity of the aforementioned models, we consider the most common standardized tests used by pharmaceutical companies to assess the addictive potential of a drug during clinical trials.

Effects of access barriers and medication acceptability on buprenorphine-naloxone treatment utilization over 2 years: Results from a multisite randomized trial of adults with opioid use disorder

BACKGROUND

Nationwide efforts seek to address the opioid epidemic by increasing access to medications for opioid use disorder (OUD), particularly with buprenorphine. A poorly understood challenge is that among individuals with OUD who do receive buprenorphine, many do not adhere to the pharmacotherapy long enough to achieve sustained benefits. We aimed to identify factors associated with buprenorphine treatment utilization over time.

METHODS

We used random-intercept modeling to identify factors associated with buprenorphine treatment utilization over 2 years after first follow-up by 789 individuals with OUD who had participated in a multi-site randomized clinical trial of buprenorphine compared to methadone. Key predictors were participants' reports of buprenorphine treatment accessibility and acceptability (assessed at first follow-up) and their interaction effects, controlling for baseline randomization status, sociodemographics, and other covariates.

RESULTS

Approximately 9.3-11.2% of participants utilized buprenorphine treatment over the 2 years of follow-up. Interaction effects indicated that individuals who perceived buprenorphine to be both accessible and acceptable were most likely to use buprenorphine during follow-up, controlling for other factors. In contrast, individuals who perceived buprenorphine to be unacceptable were least likely to use buprenorphine, regardless the level of perceived access to the medication. Buprenorphine treatment utilization was also negatively associated with Hispanic ethnicity, West coast context, and cumulative months receiving methadone treatment and incarceration during follow-up.

CONCLUSIONS

To engage more individuals with OUD in long-term treatment with buprenorphine, interventions should target buprenorphine treatment acceptability, in addition to increasing buprenorphine access, and tailor efforts to meet the needs of vulnerable populations.

TRIAL REGISTRATION

The START Follow-up Study on ClinicalTrials.gov (NCT01592461).

Stress and opioid use disorder: A systematic review

Medication assisted treatment (MAT) is highly effective in reducing illicit opioid use and preventing overdose in individuals with opioid use disorder (OUD); however, treatment retention of patients engaged in MAT is a significant clinical concern. The experience of stress may contribute to a decision to drop out of treatment. The current study is a systematic review conducted across multiple databases of empirical studies on primary appraisal of stress and its relationship to opioid craving, opioid use, and OUD treatment outcomes. Primary appraisal of stress is defined as an explicit inquiry into individual perception of feeling stressed using a self-report measure administered in laboratory, clinical, or naturalistic environment. A total of 21 included studies were organized into three categories: observed stress, experimentally-induced stress, and stress-focused interventions. Appraised stress was generally associated with greater craving, but associations with opioid use and treatment retention were mixed. All but one study included MAT samples and every study sample included some form of drug counseling. These findings suggest that individuals experience considerable stress in spite of receiving standard treatment for OUD. Psychopharmacological interventions targeting stress were promising, but no behavioral interventions specific to stress management were found. The preliminary results with clonidine and lofexidine targeting stress in individuals with OUD warrant further studies. To better understand the impact of stress in OUD, future research should consider using repeated assessment of stress in the context of daily life. Utilization of behavioral treatments specifically targeting stress could have benefits in improving OUD outcomes.

A day-by-day prospective analysis of stress, craving and risk of next day alcohol intake during alcohol use disorder treatment

BACKGROUND

Stress has been known to increase craving in individuals with Alcohol Use Disorders (AUD) and predict future alcohol relapse risk, but whether stress on a particular day affects craving on that day to impact prospective alcohol intake in the real world, particularly during early treatment and recovery, has not been studied thus far.

METHOD

The first study included 85 AUD individuals who reported their daily stress, craving, and alcohol intake in the first two weeks of early treatment. A second validation study included 28 AUD patients monitored daily during eight weeks of outpatient 12-Step based behavioral counseling treatment for AUD. Data were collected from telephone-based daily diaries for 903 days in Study 1 and 1488 in Study 2. Multilevel latent models tested if daily and person-averaged craving mediated the link between stressful events and next day drinking during treatment.

RESULTS

In both Study 1 and 2, exposure to a stressful event on a particular day predicted increased craving on that day (p's≤.002); and such increases in craving predicted the likelihood of drinking the next day (p's≤.014) and the drinking amount (p's< = 008). Individuals who experienced more stressful events reported higher craving (p's≤.012), and higher cravers reported greater next day drinking (p's<.001).

CONCLUSIONS

The results across two studies with separate samples are the first to establish that craving directly mediates the association between stress and next day alcohol intake in individuals with AUD. Findings suggest a need for novel treatment approaches to address stress-induced craving to improve alcohol use outcomes.

Conjugate vaccine produces long-lasting attenuation of fentanyl vs. food choice and blocks expression of opioid withdrawal-induced increases in fentanyl choice in rats

The current opioid crisis remains a significant public health issue and there is a critical need for biomedical research to develop effective and easily deployable candidate treatments. One emerging treatment strategy for opioid use disorder includes immunopharmacotherapies or opioid-targeted vaccines. The present study determined the effectiveness of a fentanyl-tetanus toxoid conjugate vaccine to alter fentanyl self-administration using a fentanyl-vs.-food choice procedure in male and female rats under three experimental conditions. For comparison, continuous 7-day naltrexone (0.01-0.1 mg/kg/h) and 7-day clonidine (3.2-10 μg/kg/h) treatment effects were also determined on fentanyl-vs.-food choice. Male and female rats responded for concurrently available 18% diluted Ensure® (liquid food) and fentanyl (0-10 μg/kg/infusion) infusions during daily sessions. Under baseline and saline treatment conditions, fentanyl maintained a dose-dependent increase in fentanyl-vs.-food choice. First, fentanyl vaccine administration significantly blunted fentanyl reinforcement and increased food reinforcement for 15 weeks in non-opioid dependent rats. Second, surmountability experiments by increasing the unit fentanyl dose available during the self-administration session 10-fold empirically determined that the fentanyl vaccine produced an approximate 22-fold potency shift in fentanyl-vs.-food choice that was as effective as the clinically approved treatment naltrexone. Clonidine treatment significantly increased fentanyl-vs.-food choice. Lastly, fentanyl vaccine administration prevented the expression of withdrawal-associated increases in fentanyl-vs.-food choice following introduction of extended 12 h fentanyl access sessions. Overall, these results support the potential and further consideration of immunopharmacotherapies as candidate treatments to address the current opioid crisis.

Stress, craving and mood as predictors of early dropout from opioid agonist therapy

BACKGROUND

Treatment with opioid agonists is effective for opioid use disorder, but early discontinuation of treatment is a major obstacle to success. Intensive longitudinal methods - which take many repeated measurements over time, usually in the field- have provided unique insight into the effects of stress, mood and craving on drug use while people are being treated; these methods might also be useful for studying the processes that lead people to drop out of treatment.

METHODS

Ecological momentary assessment (EMA) was conducted for up to 17 weeks by obtaining multiple electronic diary entries per day from 238 participants being treated with methadone or buprenorphine-naloxone. Survival analysis was used to study two outcomes: dropping out of treatment and noncompliance with EMA self-report requirements. Self-reports of stress, craving, and mood were used as time-varying predictors. Demographic and psychosocial variables measured with the Addiction Severity Index at the start of treatment were used as time-invariant predictors.

RESULTS

Dropping out of treatment was more likely in participants with more reported hassles (a measure of stress), higher levels of cocaine craving, lower levels of positive mood, a recent history of emotional abuse, a recent history of being bothered frequently by psychological problems, and with buprenorphine rather than methadone as their medication. In contrast, study noncompliance was not significantly associated with any of the variables analyzed.

CONCLUSIONS

Assessment of stress, craving and mood during treatment might identify people who are at greater risk of dropping out, and therapeutic interventions targeting these processes might increase retention.

Lofexidine in Combination With Oral Naltrexone for Opioid Use Disorder Relapse Prevention: A Pilot Randomized, Double-Blind, Placebo-Controlled Study

BACKGROUND AND OBJECTIVES

Lofexidine (LFX), an α2A adrenergic receptor agonist, known to alleviate opioid withdrawal symptoms, was assessed in combination with oral naltrexone (NTX) for effects on opioid use outcomes and NTX treatment compliance.

METHODS

Detoxified individuals (ages 18-55, 80% male) with opioid use disorder Diagnostic and Statistical Manual of Mental Disorders, 4th edition were randomized to 2.4 mg/day of LFX (n = 26) or Placebo (PBO, n = 31) in a double-blind manner for 12 weeks of treatment. NTX compliance, opioid-free urine samples, opioid craving as well as vital signs, subjective opioid withdrawal symptoms were assessed.

RESULTS

Intent to treat analysis revealed significantly better control over opioid craving in the LFX/NTX vs PBO/NTX group (P < .03), but no differences between groups in NTX compliance, opioid use, and overall opioid craving. However, subject withdrawal due to medication intolerance was significantly higher in the LFX/NTX (5/26) vs PBO/NTX (0/31) (P < .01). Two additional patients were withdrawn due to acute hepatitis infection. Post hoc secondary analyses with the nonwithdrawn sample indicated significantly higher rates of treatment completion (P < .05) and NTX compliance (P < .01), lower percent opioid urine samples (P < .05), and lower overall opioid craving (P < .05) in the LFX/NTX vs the PBO/NTX group.

CONCLUSION AND SCIENTIFIC SIGNIFICANCE

Although preliminary, these findings suggest that LFX at doses up to 2.4 mg/daily was safe and improved control over opioid cravings. Among those who tolerated the medication, LFX/NTX significantly improved the opioid craving, delayed return to opioid use, and improved treatment compliance and completion rates. These findings support further assessment of LFX dose titration schedule along with the adjunctive use of LFX with NTX treatment to enhance opioid relapse prevention. (Am J Addict 2019;00:1-9).

Keeping Up with Clinical Advances: Opioid Use Disorder

Opioid use disorder (OUD) is a disorder that can lead to several negative outcomes, including overdose and death. A variety of opioids can be abused by individuals including both prescribed and non-prescribed opioids. Continued opioid use can be driven by negative affective states associated with opioid withdrawal. Several treatments exist in the field including medication assisted treatments such as methadone, buprenorphine, and naltrexone. Treatments such as clonidine and lofexidine can also be used to assist with decreasing withdrawal symptoms. Increasing adherence to treatment can further improve patient outcomes and promote continuation with treatment. A variety of methods to reduce relapse can also be utilized such as opioid agonists and maintenance therapy. According to the Centers for Disease Control, opioid overdoses contributed to 67.8% of overdose deaths in 2017.

Management of Opioid Use Disorder Treatment: An Overview

It is important for nurses not working in the area of addictions to be informed of the diagnosis and treatment of opioid use disorder so that they may serve as a resource, educate others, and influence and refer individuals to seek treatment on the basis of best evidence. In this article, we provide an overview of the postscreening diagnosis and treatment of opioid use disorders with an emphasis on medication-assisted treatment, starting with the definition of substance use disorder, tolerance, dependence, and addiction.

Relapse to opioid seeking in rat models: behavior, pharmacology and circuits

Lifetime relapse rates remain a major obstacle in addressing the current opioid crisis. Relapse to opioid use can be modeled in rodent studies where drug self-administration is followed by a period of abstinence and a subsequent test for drug seeking. Abstinence can be achieved through extinction training, forced abstinence, or voluntary abstinence. Voluntary abstinence can be accomplished by introducing adverse consequences of continued drug self-administration (e.g., punishment or electric barrier) or by introducing an alternative nondrug reward in a discrete choice procedure (drug versus palatable food or social interaction). In this review, we first discuss pharmacological and circuit mechanisms of opioid seeking, as assessed in the classical extinction-reinstatement model, where reinstatement is induced by reexposure to the self-administered drug (drug priming), discrete cues, discriminative cues, drug-associated contexts, different forms of stress, or withdrawal states. Next, we discuss pharmacological and circuit mechanisms of relapse after forced or voluntary abstinence, including the phenomenon of "incubation of heroin craving" (the time-dependent increases in heroin seeking during abstinence). We conclude by discussing future directions of preclinical relapse-related studies using opioid drugs.

Investigating Health Risk Environments in Housing Programs for Young Adults: Protocol for a Geographically Explicit Ecological Momentary Assessment Study

Background

Young adults who experience homelessness are exposed to environments that contribute to risk behavior. However, few studies have examined how access to housing may affect the health risk behaviors of young adults experiencing homelessness.

Objective

This paper describes the Log My Life study that uses an innovative, mixed-methods approach based on geographically explicit ecological momentary assessment (EMA) through cell phone technology to understand the risk environment of young adults who have either enrolled in housing programs or are currently homeless.

Methods

For the quantitative arm, study participants age 18-27 respond to momentary surveys via a smartphone app that collects geospatial information repeatedly during a 1-week period. Both EMAs (up to 8 per day) and daily diaries are prompted to explore within-day and daily variations in emotional affect, context, and health risk behavior, while also capturing infrequent risk behaviors such as sex in exchange for goods or services. For the qualitative arm, a purposive subsample of participants who indicated engaging in risky behaviors are asked to complete an in-depth qualitative interview using an interactive, personalized geospatial map rendering of EMA responses.

Results

Recruitment began in June of 2017. To date, 170 participants enrolled in the study. Compliance with EMA and daily diary surveys was generally high. In-depth qualitative follow-ups have been conducted with 15 participants. We expect to recruit 50 additional participants and complete analyses by September of 2019.

Conclusions

Mixing the quantitative and qualitative arms in this study will provide a more complete understanding of differences in risk environments between homeless and housed young adults. Furthermore, this approach can improve recall bias and enhance ecological validity.

International Registered Report Identifier (IRRID)

DERR1-10.2196/12112

Pharmacological and Behavioral Treatment of Opioid Use Disorder

Objective:

Opioid use disorder (OUD) in the United States has surged, with an estimated 2.5 million needing treatment. The aim of this article is to provide a clinical overview of the key pharmacological and behavioral treatments for OUD.

Methods:

A nonsystematic review of the literature was conducted to investigate OUD treatments, including their mechanism of action, efficacy, clinical guidelines in the United States, and consideration of frequently occurring comorbid conditions.

Results:

Food and Drug Administration (FDA)–approved pharmacotherapies for OUD include methadone, buprenorphine, and naltrexone, each of which has different actions on opioid receptors. Although these medications all show efficacy in some dosages and formulations, barriers to accessibility may be most pronounced for methadone, whereas treatment retention poses greater challenges for naltrexone and, to a lesser extent, buprenorphine. Lofexidine, an α₂‐adrenergic agonist, has recently been approved by the FDA for treatment of opioid withdrawal symptoms. OUD is commonly treated with medication‐assisted treatment (MAT), which offers pharmacotherapy in the context of counseling and/or behavioral treatments. Behavioral therapies, rarely offered as stand‐alone treatments for OUD, are generally used in the context of MAT, in structured settings or to prevent relapse after detoxification and stabilization. The aim of behavioral interventions is to improve medication compliance and target problems not addressed with medication alone. Individuals with OUD commonly have other comorbid psychiatric and substance use conditions, which are not exclusionary for initiating MAT but should be carefully evaluated and monitored because they may reduce treatment effectiveness.

Conclusions:

MAT is the first‐line treatment for patients with OUD and should be provided in combination with behavioral interventions. Treatment retention remains challenging in this population. Future studies should focus on approaches that will serve the complex needs of patients with OUD, including those with comorbid psychiatric and substance use conditions.

Impact of psychiatric medication co-exposure on Neonatal Abstinence Syndrome severity

BACKGROUND

Among opioid-exposed infants, psychiatric medication co-exposure is common. Our objective was to compare Neonatal Abstinence Syndrome (NAS) outcomes based on individual psychiatric medication co-exposures.

METHODS

A retrospective study of 744 opioid-exposed mother-infant dyads from a single institution was performed. Mothers on pharmacotherapy with methadone or buprenorphine at delivery were included. Data were collected on maternal demographics, psychiatric medication use, and NAS outcomes, including any medication treatment, adjunctive medication treatment, length of hospital stay (LOS), and opioid treatment days. The extent to which individual psychiatric medication and polypharmacy exposure were associated with NAS outcomes was assessed using multivariable regression.

RESULTS

Fifty-four percent of the mothers were on ≥1 psychiatric medication, with 32% on ≥2 or psychiatric medications (polypharmacy group). In adjusted models, polypharmacy exposure was associated with longer LOS (β = 4.31 days, 95% CI 2.55-6.06) and opioid treatment days (β = 3.98 days, 95% CI 2.24-5.72) and more treatment with adjunctive medication for NAS (aOR = 2.49, 95% CI 1.57-3.95). Benzodiazepines were associated with longer LOS (β = 4.94, 95% CI 2.86-7.03) and opioid treatment days (β = 4.86, 95% CI 2.61-6.75), and more adjunctive medication treatment (aOR = 2.57, 95% CI 1.49-4.42). Gabapentin was associated with longer LOS (β = 2.79, 95% CI 0.54-5.03), more NAS medication treatment (aOR = 2.96, 95% CI 1.18-7.42) including more adjunctive medications (aOR = 1.92, 95% CI 1.05-3.53).

CONCLUSION

For infants of mothers with OUD who are also on concurrent psychiatric medications, polypharmacy was associated with worse NAS severity. When medically indicated, limiting use of multiple psychiatric medications, particularly benzodiazepines and gabapentin, during pregnancy should be considered to improve NAS outcomes.

Anti-stress neuropharmacological mechanisms and targets for addiction treatment: A translational framework

Stress-related substance use is a major challenge for treating substance use disorders. This selective review focuses on emerging pharmacotherapies with potential for reducing stress-potentiated seeking and consumption of nicotine, alcohol, marijuana, cocaine, and opioids (i.e., key phenotypes for the most commonly abused substances). I evaluate neuropharmacological mechanisms in experimental models of drug-maintenance and relapse, which translate more readily to individuals presenting for treatment (who have initiated and progressed). An affective/motivational systems model (three dimensions: valence, arousal, control) is mapped onto a systems biology of addiction approach for addressing this problem. Based on quality of evidence to date, promising first-tier neurochemical receptor targets include: noradrenergic (α1 and β antagonist, α2 agonist), kappa-opioid antagonist, nociceptin antagonist, orexin-1 antagonist, and endocannabinoid modulation (e.g., cannabidiol, FAAH inhibition); second-tier candidates may include corticotropin releasing factor-1 antagonists, serotonergic agents (e.g., 5-HT reuptake inhibitors, 5-HT3 antagonists), glutamatergic agents (e.g., mGluR2/3 agonist/positive allosteric modulator, mGluR5 antagonist/negative allosteric modulator), GABA-promoters (e.g., pregabalin, tiagabine), vasopressin 1b antagonist, NK-1 antagonist, and PPAR-γ agonist (e.g., pioglitazone). To address affective/motivational mechanisms of stress-related substance use, it may be advisable to combine agents with actions at complementary targets for greater efficacy but systematic studies are lacking except for interactions with the noradrenergic system. I note clinically-relevant factors that could mediate/moderate the efficacy of anti-stress therapeutics and identify research gaps that should be pursued. Finally, progress in developing anti-stress medications will depend on use of reliable CNS biomarkers to validate exposure-response relationships.

Sexual dimorphism in the neural impact of stress and alcohol

Alcohol use disorder is a widespread mental illness characterized by periods of abstinence followed by recidivism, and stress is the primary trigger of relapse. Despite the higher prevalence of alcohol use disorder in males, the relationship between stress and behavioral features of relapse, such as craving, is stronger in females. Given the greater susceptibility of females to stress-related psychiatric disorders, understanding sexual dimorphism in the relationship between stress and alcohol use is essential to identifying better treatments for both male and female alcoholics. This review addresses sex differences in the impact of stressors on alcohol drinking and seeking in rodents and humans. As these behavioral differences in alcohol use and relapse originate from sexual dimorphism in neuronal function, the impact of stressors and alcohol, and their interaction, on molecular adaptations and neural activity in males and females will also be discussed. Together, the data reviewed herein, arising from a symposium titled "Sex matters in stress-alcohol interactions" presented at the Fourth Volterra Conference on Stress and Alcohol, will highlight the importance of identifying sex differences to improve treatments for comorbid stress and alcohol use disorder in both sexes.