Effect of scanning duration and sample size on reliability in resting state fMRI dynamic causal modeling analysis

Despite its widespread use, resting-state functional magnetic resonance imaging (rsfMRI) has been criticized for low test-retest reliability. To improve reliability, researchers have recommended using extended scanning durations, increased sample size, and advanced brain connectivity techniques. However, longer scanning runs and larger sample sizes may come with practical challenges and burdens, especially in rare populations. Here we tested if an advanced brain connectivity technique, dynamic causal modeling (DCM), can improve reliability of fMRI effective connectivity (EC) metrics to acceptable levels without extremely long run durations or extremely large samples. Specifically, we employed DCM for EC analysis on rsfMRI data from the Human Connectome Project. To avoid bias, we assessed four distinct DCMs and gradually increased sample sizes in a randomized manner across ten permutations. We employed pseudo true positive and pseudo false positive rates to assess the efficacy of shorter run durations (3.6, 7.2, 10.8, 14.4 min) in replicating the outcomes of the longest scanning duration (28.8 min) when the sample size was fixed at the largest (n = 160 subjects). Similarly, we assessed the efficacy of smaller sample sizes (n = 10, 20, …, 150 subjects) in replicating the outcomes of the largest sample (n = 160 subjects) when the scanning duration was fixed at the longest (28.8 min). Our results revealed that the pseudo false positive rate was below 0.05 for all the analyses. After the scanning duration reached 10.8 min, which yielded a pseudo true positive rate of 92%, further extensions in run time showed no improvements in pseudo true positive rate. Expanding the sample size led to enhanced pseudo true positive rate outcomes, with a plateau at n = 70 subjects for the targeted top one-half of the largest ECs in the reference sample, regardless of whether the longest run duration (28.8 min) or the viable run duration (10.8 min) was employed. Encouragingly, smaller sample sizes exhibited pseudo true positive rates of approximately 80% for n = 20, and 90% for n = 40 subjects. These data suggest that advanced DCM analysis may be a viable option to attain reliable metrics of EC when larger sample sizes or run times are not feasible.

Initial Validation of a Behavioral Phenotyping Model for Substance Use Disorder

Standard nosological systems, such as DSM-5 or ICD-10, are relied upon as the diagnostic basis when developing treatments for individuals with substance use disorder (SUD). Unfortunately, the vast heterogeneity of individuals within a given SUD diagnosis results in a variable treatment response and/or difficulties ascertaining the efficacy signal in clinical trials of drug development. Emerging precision medicine methods focusing on targeted treatments based on phenotypic subtypes rather than diagnosis are being explored as alternatives. The goal of the present study was to provide initial validation of emergent subtypes identified by an addiction-focused phenotyping battery. Secondary data collected as part of a feasibility study of the NIDA phenotyping battery were utilized. Participants completed self-report measures and behavioral tasks across six neurofunctional domains. Exploratory and confirmatory factor analysis (EFA/CFA) were conducted. A three-factor model consisting of negative emotionality, attention/concentration, and interoception and mindfulness, as well as a four-factor model adding a second negative emotion domain, emerged from the EFA as candidate models. The CFA of these models did not result in a good fit, possibly resulting from small sample sizes that hindered statistical power.

Outcomes of Emergency Department Patients With Opioid Use Disorder Utilizing a Virtual Addiction Bridge Clinic: A Case Series

OBJECTIVES

Within the last decade, there has been a dramatic increase in the rate of emergency department (ED) visits and death from opioid overdose. Those who present to the ED are at high risk for subsequent morbidity and mortality. Despite effective treatment, many patients do not get rapidly connected to outpatient care. The aim of this investigation was to describe outpatient treatment engagement after ED discharge among patients with opioid use disorder (OUD) enrolled in a virtual Addiction Bridge Clinic (ABC).

METHODS

This was a retrospective case series describing an ED-initiated referral for rapid telehealth follow-up among patients with OUD. The primary outcome was addiction treatment engagement among those who completed the initial virtual ABC visit (engaged in ABC) vs. those who did not complete an ABC visit (Not engaged in ABC) at 1 week, 1 month, and 3 and 6 months timepoint intervals after the initial ED presentation.

RESULTS

Of the N = 201 patients referred to the ABC between March and December 2021, a majority were Black (71%) and male (77%). Of the 201 referrals, 85 (42%) completed an initial ABC telehealth visit. Subsequent treatment engagement was 26% at 1 week, 26% at 1 month, 22% at 3 months, and 18% at 6 months after the index ED visit.

CONCLUSIONS

A telehealth-enabled virtual addiction bridge clinic is one potential approach to reduce barriers to rapid treatment access. Strategies are needed to improve subsequent addiction treatment engagement after a virtual addiction bridge clinic visit.

Ghrelin receptor antagonist JMV2959 blunts cocaine and oxycodone drug-seeking, but not self-administration, in male rats

The drug overdose crisis has spawned serious health consequences, including the increased incidence of substance use disorders (SUDs), conditions manifested by escalating medical and psychological impairments. While medication management is a key adjunct in SUD treatment, this crisis has crystallized the need to develop additional therapeutics to facilitate extended recovery from SUDs. The "hunger hormone" ghrelin acts by binding to the growth hormone secretagogue receptor 1α (GHS1αR) to control homeostatic and hedonic aspects of food intake and has been implicated in the mechanisms underlying SUDs. Preclinical studies indicate that GHS1αR antagonists and inverse agonists suppress reward-related signaling associated with cocaine and opioids. In the present study, we found that the GHS1αR antagonist JMV2959 was efficacious to suppress both cue-reinforced cocaine and oxycodone drug-seeking, but not cocaine or oxycodone self-administration in male Sprague-Dawley rats. These data suggest a role of the ghrelin-GHS1αR axis in mediating overlapping reward-related aspects of cocaine and oxycodone and premises the possibility that a GHS1αR antagonist may be a valuable therapeutic strategy for relapse vulnerability in SUDs.

Behavioral and neurocognitive factors distinguishing post-traumatic stress comorbidity in substance use disorders

Significant trauma histories and post-traumatic stress disorder (PTSD) are common in persons with substance use disorders (SUD) and often associate with increased SUD severity and poorer response to SUD treatment. As such, this sub-population has been associated with unique risk factors and treatment needs. Understanding the distinct etiological profile of persons with co-occurring SUD and PTSD is therefore crucial for advancing our knowledge of underlying mechanisms and the development of precision treatments. To this end, we employed supervised machine learning algorithms to interrogate the responses of 160 participants with SUD on the multidimensional NIDA Phenotyping Assessment Battery. Significant PTSD symptomatology was correctly predicted in 75% of participants (sensitivity: 80%; specificity: 72.22%) using a classification-based model based on anxiety and depressive symptoms, perseverative thinking styles, and interoceptive awareness. A regression-based machine learning model also utilized similar predictors, but failed to accurately predict severity of PTSD symptoms. These data indicate that even in a population already characterized by elevated negative affect (individuals with SUD), especially severe negative affect was predictive of PTSD symptomatology. In a follow-up analysis of a subset of 102 participants who also completed neurocognitive tasks, comorbidity status was correctly predicted in 86.67% of participants (sensitivity: 91.67%; specificity: 66.67%) based on depressive symptoms and fear-related attentional bias. However, a regression-based analysis did not identify fear-related attentional bias as a splitting factor, but instead split and categorized the sample based on indices of aggression, metacognition, distress tolerance, and interoceptive awareness. These data indicate that within a population of individuals with SUD, aberrations in tolerating and regulating aversive internal experiences may also characterize those with significant trauma histories, akin to findings in persons with anxiety without SUD. The results also highlight the need for further research on PTSD-SUD comorbidity that includes additional comparison groups (i.e., persons with only PTSD), captures additional comorbid diagnoses that may influence the PTSD-SUD relationship, examines additional types of SUDs (e.g., alcohol use disorder), and differentiates between subtypes of PTSD.

Rising Racial Disparities in Opioid Mortality and Undertreatment of Opioid Use Disorder and Mental Health Comorbidities in Virginia

Introduction

There were more than 100,000 fatal drug overdoses in the U.S. in 2021 alone. In recent years, there has been a shift in opioid mortality from predominantly White rural communities to Black urban communities. This study aimed to identify the Virginia communities disproportionately affected by the overdose crisis and to better understand the systemic factors contributing to disparities in opioid mortality.

Methods

Using the state all-payer claims database, state mortality records, and census data, we created a multivariate model to examine the community-level factors contributing to racial disparities in opioid mortality. We used generalized linear mixed models to examine the associations between socioecologic factors and fatal opioid overdoses, opioid use disorder diagnoses, opioid-related emergency department visits, and mental health diagnoses.

Results

Between 2015 and 2020, racial disparities in mortality widened. In 2020, Black males were 1.5 times more likely to die of an opioid overdose than White males (47.3 vs 31.6 per 100,000; p<0.001). The rate of mental health disorders strongly correlated with mortality (β=0.53, p<0.001). Black individuals are not more likely to be diagnosed with opioid use disorder (β=0.01, p=0.002) or with mental health disorders (β= -0.12, p<0.001), despite higher fatal opioid overdoses.

Conclusions

There are widening racial disparities in opioid mortality. Untreated mental health disorders are a major risk factor for opioid mortality. Findings show pathways to address inequities, including early linkage to care for mental health and opioid use disorders. This analysis shows the use of comprehensive socioecologic data to identify the precursors to fatal overdoses, which could allow earlier intervention and reallocation of resources in high-risk communities.

Chronic Cocaine Use and White Matter Coherence: A Diffusion Tensor Imaging Study

OBJECTIVE

Chronic substance use and its effects on brain function and structure has long been of interest to clinicians and researchers. Prior cross-sectional comparisons of diffusion tensor imaging (DTI) metrics have suggested deleterious effects of chronic substance use (i.e., cocaine use) on white matter coherence. However, it is unclear how these effects may replicate across geographic regions when examined with similar technologies. In this study, we sought to conduct a replication of previous work in this area and determine whether there are any patterns of persistent differences in white matter microstructure between individuals with a history of cocaine use disorder (CocUD, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) and healthy controls.

METHOD

A total of 46 participants (21 healthy controls, 25 chronic cocaine users) were recruited from the Richmond, Virginia metropolitan area. Information regarding past and current substance use was collected from all participants. Participants also completed structural and DTI scans.

RESULTS

Consistent with previous DTI studies, significant differences were found between fractional anisotropy (FA) and axial diffusivity (AD) CocUD and controls, with CocUD showing lower FA and AD in the right inferior and superior longitudinal fasciculus, the genu, body, and splenium of the corpus callosum, and the anterior, posterior, and superior corona radiata, among several other regions. These differences were not significant for other diffusivity metrics. Lifetime alcohol consumption was greater in the CocUD group, but lifetime alcohol consumption did not show a significant linear relationship with any of the DTI metrics in within-group regression analyses.

CONCLUSIONS

These data align with previously reported declines in white matter coherence in chronic cocaine users. However, it is less clear whether comorbid alcohol consumption results in an additive deleterious effect on white matter microstructure.

Benzodiazepine, Z-drug, and sleep medication prescriptions in male and female people with opioid use disorder on buprenorphine and comorbid insomnia: an analysis of multistate insurance claims

STUDY OBJECTIVES

In adult populations, women are more likely than men to be prescribed benzodiazepines. However, such disparities have not been investigated in people with opioid use disorder (OUD) and insomnia receiving buprenorphine, a population with particularly high sedative/hypnotic receipt. This retrospective cohort study used administrative claims data from Merative MarketScan Commercial and MultiState Medicaid Databases (2006-2016) to investigate sex differences in the receipt of insomnia medication prescriptions among patients in OUD treatment with buprenorphine.

METHODS

We included people aged 12-64 years with diagnoses of insomnia and OUD-initiating buprenorphine during the study timeframe. The predictor variable was sex (female versus male). The primary outcome was receipt of insomnia medication prescription within 60 days of buprenorphine start, encompassing benzodiazepines, Z-drugs, or non-sedative/hypnotic insomnia medications (e.g. hydroxyzine, trazodone, and mirtazapine). Associations between sex and benzodiazepine, Z-drug, and other insomnia medication prescription receipt were estimated using Poisson regression models.

RESULTS

Our sample included 9510 individuals (female n = 4637; male n = 4873) initiating buprenorphine for OUD who also had insomnia, of whom 6569 (69.1%) received benzodiazepines, 3891 (40.9%) Z-drugs, and 8441 (88.8%) non-sedative/hypnotic medications. Poisson regression models, adjusting for sex differences in psychiatric comorbidities, found female sex to be associated with a slightly increased likelihood of prescription receipt: benzodiazepines (risk ratio [RR], RR = 1.17 [1.11-1.23]), Z-drugs (RR = 1.26 [1.18-1.34]), and non-sedative/hypnotic insomnia medication (RR = 1.07, [1.02-1.12]).

CONCLUSIONS

Sleep medications are commonly being prescribed to individuals with insomnia in OUD treatment with buprenorphine, with sex-based disparities indicating a higher prescribing impact among female than male OUD treatment patients.

Case report: Identification of AP-238 and 2-fluorodeschloroketamine in internet available powder samples sold as bucinnazine

Novel synthetic opioids (NSOs) are a class of opioid agonists that include analogs of fentanyl and structurally distinct non-fentanyl compounds normally used as standalone products, heroin adulterants, or constituents of counterfeit pain pills. Most NSOs are not currently scheduled in the U.S., are predominantly illegally synthesized, and sold on the Darknet. Among them, the cinnamylpiperazine derivatives such as bucinnazine (AP-237), AP-238, and 2-methyl-AP-237 and the arylcyclohexylamine derivatives, analogs of ketamine, such as 2-fluoro-deschloroketamine (2 F-DCK) have appeared in several monitoring systems. Two white powders purchased on the internet as bucinnazine were first analyzed with polarized light microscopy followed by direct analysis in real time-mass spectrometry (DART-MS) and gas chromatography-mass spectrometry (GC-MS). Both powders were white crystals with no other significant microscopic properties. The DART-MS analysis showed the presence of 2-fluorodeschloroketamine in powder #1, and AP-238 in powder #2. Identification was confirmed by GC-MS. The purity of each substance was 78.0% for powder #1, and 88.9% for powder #2, respectively. The toxicological risk associated with the misuse of NSOs still needs further study. The absence of bucinnazine and the presence of different active compounds in internet purchased samples raises public health and safety concerns.

New approaches to deep phenotyping in addictions

OBJECTIVE

The causes of substance use disorders (SUDs) are largely unknown and the effectiveness of their treatments is limited. One crucial impediment to research and treatment progress surrounds how SUDs are classified and diagnosed. Given the substantial heterogeneity among individuals diagnosed with a given SUD (e.g., alcohol use disorder [AUD]), identifying novel research and treatment targets and developing new study designs is daunting.

METHOD

In this article, we review and integrate two recently developed frameworks, the National Institute on Drug Abuse's Phenotyping Assessment Battery (NIDA PhAB) and the Hierarchical Taxonomy of Psychopathology (HiTOP), that hope to accelerate progress in understanding the causes and consequences of psychopathology by means of deep phenotyping, or finer-grained analysis of phenotypes.

RESULTS AND CONCLUSIONS

NIDA PhAB focuses on addiction-related processes across multiple units of analysis, whereas HiTOP focuses on clinical phenotypes and covers a broader range of psychopathology. We highlight that NIDA PhAB and HiTOP together provide deep and broad characterizations of people diagnosed with SUDs and complement each other in their efforts to address widely known limitations of traditional classification systems and their diagnostic categories. Next, we show how NIDA PhAB and HiTOP can be integrated to facilitate optimal rich phenotyping of addiction-related phenomena. Finally, we argue that such deep phenotyping promises to advance our understanding of the neurobiology of SUD and addiction, which will guide the development of personalized medicine and interventions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Use of population health data to promote equitable recruitment for a primary care practice implementation trial addressing unhealthy alcohol use

Background

Recruiting underrepresented people and communities in research is essential for generalizable findings. Ensuring representative participants can be particularly challenging for practice-level dissemination and implementation trials. Novel use of real-world data about practices and the communities they serve could promote more equitable and inclusive recruitment.

Methods

We used a comprehensive primary care clinician and practice database, the Virginia All-Payers Claims Database, and the HealthLandscape Virginia mapping tool with community-level socio-ecological information to prospectively inform practice recruitment for a study to help primary care better screen and counsel for unhealthy alcohol use. Throughout recruitment, we measured how similar study practices were to primary care on average, mapped where practices' patients lived, and iteratively adapted our recruitment strategies.

Results

In response to practice and community data, we adapted our recruitment strategy three times; first leveraging relationships with residency graduates, then a health system and professional organization approach, followed by a community-targeted approach, and a concluding approach using all three approaches. We enrolled 76 practices whose patients live in 97.3% (1844 of 1907) of Virginia's census tracts. Our overall patient sample had similar demographics to the state for race (21.7% vs 20.0% Black), ethnicity (9.5% vs 10.2% Hispanic), insurance status (6.4% vs 8.0% uninsured), and education (26.0% vs 32.5% high school graduate or less). Each practice recruitment approach uniquely included different communities and patients.

Discussion

Data about primary care practices and the communities they serve can prospectively inform research recruitment of practices to yield more representative and inclusive patient cohorts for participation.

Executive control network resting state fMRI functional and effective connectivity and delay discounting in cocaine dependent subjects compared to healthy controls

Resting state functional magnetic resonance imaging (fMRI) has been used to study functional connectivity of brain networks in addictions. However, most studies to-date have focused on the default mode network (DMN) with fewer studies assessing the executive control network (ECN) and salience network (SN), despite well-documented cognitive executive behavioral deficits in addictions. The present study assessed the functional and effective connectivity of the ECN, DMN, and SN in cocaine dependent subjects (CD) (n = 22) compared to healthy control subjects (HC) (n = 22) matched on age and education. This study also investigated the relationship between impulsivity measured by delay discounting and functional and effective connectivity of the ECN, DMN, and SN. The Left ECN (LECN), Right ECN (RECN), DMN, and SN functional networks were identified using FSL MELODIC independent component analysis. Functional connectivity differences between CD and HC were assessed using FSL Dual Regression analysis and FSLNets. Effective connectivity differences between CD and HC were measured using the Parametric Empirical Bayes module of Dynamic Causal Modeling. The relationship between delay discounting and functional and effective connectivity were examined using regression analyses. Dynamic causal modeling (DCM) analysis showed strong evidence (posterior probability > 0.95) for CD to have greater effective connectivity than HC in the RECN to LECN pathway when tobacco use was included as a factor in the model. DCM analysis showed strong evidence for a positive association between delay discounting and effective connectivity for the RECN to LECN pathway and for the DMN to DMN self-connection. There was strong evidence for a negative association between delay discounting and effective connectivity for the DMN to RECN pathway and for the SN to DMN pathway. Results also showed strong evidence for a negative association between delay discounting and effective connectivity for the RECN to SN pathway in CD but a positive association in HC. These novel findings provide preliminary support that RECN effective connectivity may differ between CD and HC after controlling for tobacco use. RECN effective connectivity may also relate to tobacco use and impulsivity as measured by delay discounting.

Testing the Acceptability and Usability of an AI-Enabled COVID-19 Diagnostic Tool Among Diverse Adult Populations in the United States

BACKGROUND AND OBJECTIVES

Although at-home coronavirus disease-2019 (COVID-19) testing offers several benefits in a relatively cost-effective and less risky manner, evidence suggests that at-home COVID-19 test kits have a high rate of false negatives. One way to improve the accuracy and acceptance of COVID-19 screening is to combine existing at-home physical test kits with an easily accessible, electronic, self-diagnostic tool. The objective of the current study was to test the acceptability and usability of an artificial intelligence (AI)-enabled COVID-19 testing tool that combines a web-based symptom diagnostic screening survey and a physical at-home test kit to test differences across adults from varying races, ages, genders, educational, and income levels in the United States.

METHODS

A total of 822 people from Richmond, Virginia, were included in the study. Data were collected from employees and patients of Virginia Commonwealth University Health Center as well as the surrounding community in June through October 2021. Data were weighted to reflect the demographic distribution of patients in United States. Descriptive statistics and repeated independent t tests were run to evaluate the differences in the acceptability and usability of an AI-enabled COVID-19 testing tool.

RESULTS

Across all participants, there was a reasonable degree of acceptability and usability of the AI-enabled COVID-19 testing tool that included a physical test kit and symptom screening website. The AI-enabled COVID-19 testing tool demonstrated overall good acceptability and usability across race, age, gender, and educational background. Notably, participants preferred both components of the AI-enabled COVID-19 testing tool to the in-clinic testing.

CONCLUSION

Overall, these findings suggest that our AI-enabled COVID-19 testing approach has great potential to improve the quality of remote COVID testing at low cost and high accessibility for diverse demographic populations in the United States.

Attentional function and inhibitory control in different substance use disorders

Attentional function in substance use disorder (SUD) is not well understood. To probe attentional function in SUD as a function of primary substance of abuse, we administered the attentional network task (ANT) to 44 individuals with Cocaine Use Disorder (CoUD), 49 individuals with Cannabis Use Disorder (CaUD), 86 individuals with Opioid Use Disorder (OUD), and 107 controls with no SUD, along with the stop-signal task (SST). The ANT quantifies the effects of (temporal) alerting cues and (spatial) orienting cues to reduce reaction time (RT) to targets, as well as probing how conflicting (target-incongruent) stimuli slow RT. The SST quantifies individuals' ability to inhibit already-initiated motor responses. After controlling for sex representation and age, OUD and CaUD participants showed blunted alerting effects compared to controls, whereas CaUD and CoUD participants showed greater stimulus conflict (flanker) effects. Finally, CoUD participants showed a trend toward increased orienting ability. In SST performance, no SUD group showed a prolonged stop-signal reaction compared to controls. However, the OUD group (and CoUD group at trend level) showed prolonged "go" RT to targets and reduced hit rates. These data indicate differences in attentional function in persons with SUD as a function of the primary substance use.

Geostatistical modeling of positive-definite matrices: An application to diffusion tensor imaging

Geostatistical modeling for continuous point-referenced data has extensively been applied to neuroimaging because it produces efficient and valid statistical inference. However, diffusion tensor imaging (DTI), a neuroimaging technique characterizing the brain's anatomical structure, produces a positive-definite (p.d.) matrix for each voxel. Currently, only a few geostatistical models for p.d. matrices have been proposed because introducing spatial dependence among p.d. matrices properly is challenging. In this paper, we use the spatial Wishart process, a spatial stochastic process (random field), where each p.d. matrix-variate random variable marginally follows a Wishart distribution, and spatial dependence between random matrices is induced by latent Gaussian processes. This process is valid on an uncountable collection of spatial locations and is almost-surely continuous, leading to a reasonable way of modeling spatial dependence. Motivated by a DTI data set of cocaine users, we propose a spatial matrix-variate regression model based on the spatial Wishart process. A problematic issue is that the spatial Wishart process has no closed-form density function. Hence, we propose an approximation method to obtain a feasible Cholesky decomposition model, which we show to be asymptotically equivalent to the spatial Wishart process model. A local likelihood approximation method is also applied to achieve fast computation. The simulation studies and real data application demonstrate that the Cholesky decomposition process model produces reliable inference and improved performance, compared to other methods.

A serotonergic biobehavioral signature differentiates cocaine use disorder participants administered mirtazapine

Cocaine use disorder (CUD) patients display heterogenous symptoms and unforeseeable responses to available treatment approaches, highlighting the need to identify objective, accessible biobehavioral signatures to predict clinical trial success in this population. In the present experiments, we employed a task-based behavioral and pharmacogenetic-fMRI approach to address this gap. Craving, an intense desire to take cocaine, can be evoked by exposure to cocaine-associated stimuli which can trigger relapse during attempted recovery. Attentional bias towards cocaine-associated words is linked to enhanced effective connectivity (EC) from the anterior cingulate cortex (ACC) to hippocampus in CUD participants, an observation which was replicated in a new cohort of participants in the present studies. Serotonin regulates attentional bias to cocaine and the serotonergic antagonist mirtazapine decreased activated EC associated with attentional bias, with greater effectiveness in those CUD participants carrying the wild-type 5-HT2CR gene relative to a 5-HT2CR single nucleotide polymorphism (rs6318). These data suggest that the wild-type 5-HT2CR is necessary for the efficacy of mirtazapine to decrease activated EC in CUD participants and that mirtazapine may serve as an abstinence enhancer to mitigate brain substrates of craving in response to cocaine-associated stimuli in participants with this pharmacogenetic descriptor. These results are distinctive in outlining a richer "fingerprint" of the complex neurocircuitry, behavior and pharmacogenetics profile of CUD participants which may provide insight into success of future medications development projects.

Sex Specific Sleep Parameters Among People With Substance Use Disorder

INTRODUCTION

Sleep can have substantial impacts in substance use disorder (SUD) pathogenesis, treatment, and recovery. Sex differences exist in both sleep and SUD, but how sleep is uniquely associated with SUD by sex is not known. The study objective was to compare, within sex, sleep parameters between individuals with SUD and non-substance misusing controls.

METHODS

Secondary analyses of a parent cross-sectional study examining the feasibility and acceptability of a novel neurocognitive phenotyping assessment battery were completed. SUD and control subjects were recruited through local advertising and an established research registry. Subjects with SUD were also recruited through a university-based outpatient SUD treatment clinic. Self-reported sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Sex-stratified t-tests compared sleep between SUD and control subjects while Crosstab analyses explored group differences in the proportion of individuals reporting poor sleep (defined as PSQI ≥ 5).

RESULTS

Data from 162 males (44 controls, 118 SUD) and 146 females (64 controls, 82 SUD) were included in the present study. For females only, a significantly lower proportion of controls reported PSQI-defined poor sleep than individuals with any SUD or specifically with opioid use disorder. Male, but not female, controls reported shorter sleep latency, longer sleep duration, and less sleep disturbance than males with each SUD type.

DISCUSSION/IMPLICATIONS

Sleep holds promise as an avenue to address SUD within a biopsychosocial model. Future work at the intersection of SUD and sleep should prioritize investigations of their interplay with sex to identify targets for tailored SUD interventions.

Clinical features and outcomes between African American and Caucasian patients with Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome (TS) is an acute, reversible form of heart failure, often mimicking an acute coronary syndrome (ACS). Data regarding racial differences in TS are inconsistent. The aim is to assess clinical features associated with unfavorable in-hospital outcomes between African American (AA) and Caucasian (CAU) patients.

METHODS

A retrospective electronic health record query identified 44 AA patients and 110 CAU patients with a diagnosis of TS. Our primary outcome was a composite of death, stroke, and cardiogenic shock during hospitalization. Variables associated with an increased risk of the primary composite outcomes were included in a logistic regression model.

RESULTS

Compared to CAU patients, AA patients were a more comorbid population, and presented a higher prevalence of history of illicit drug use (27.3% vs. 13.6% P=0.044). There were no significant differences regarding in-hospital complication rates between AA and CAU patients. In the logistic regression model, infection was associated with greater risk of developing the primary outcome in AA patients (OR=7.26 [95% CI 1.22-43.17], P=0.029), whereas angina was a protective factor (OR=0.11 [95% CI 0.02-0.65], P=0.015). In CAU patients, severely depressed ejection fraction and worse peak creatinine during hospitalization increased risk of developing the primary outcome (OR=5.88 95% CI [2.01-17.17], P<0.001 and OR=1.64 [95% CI 1.15-2.58], P=0.031, respectively). Meanwhile, emotional stressors were protective (OR=0.16 [95% CI 0.03-0.88], P=0.004).

CONCLUSIONS

Despite experiencing the same rate of in-hospital complications, the clinical profiles of AA patients are distinct from CAU patients admitted for TS, and clinical variables correlated with worse in-hospital outcomes also differ by race.

Citalopram for treatment of cocaine use disorder: A Bayesian drop-the-loser randomized clinical trial

BACKGROUND

Medication development research for cocaine use disorder (CUD) has been a longstanding goal in addiction research, but has not resulted in an FDA-approved treatment. Rising cocaine use rates underscore the need for efficient adaptive designs. This study compared differences between two doses of the selective serotonin reuptake inhibitor (SSRI) citalopram (versus placebo) on duration of cocaine abstinence and applied adaptive decision rules to select the 'best efficacy' dose.

METHODS

A double-blind, placebo-controlled, randomized Bayesian drop-the-loser (DTL) trial with three arms compared placebo to citalopram 20 mg and 40 mg. Adults (N = 107) with CUD attended thrice-weekly clinic visits for 9 weeks. The primary outcome was longest duration of abstinence (LDA), based on continuous cocaine-negative urine drug screens (UDS). The secondary outcome was probability of cocaine-negative UDS during treatment. A planned interim analysis performed at approximately 50% of recruitment dropped the least-effective active medication. Bayesian inference was used for all analyses with a pre-specified posterior probability (PP) threshold PP ≥ 95% considered statistically reliable evidence RESULTS: Citalopram 40 mg satisfied interim efficacy criteria and was retained for the second half of the trial. For LDA, analyses indicated PP = 82% and PP = 65% of benefit for 40 mg and 20 mg, respectively (each relative to placebo). The odds of having cocaine-negative UDS decreased in all groups over 9 weeks but remained higher for 40 mg (PP = 97.4%) CONCLUSIONS: Neither dose met the 95% PP threshold for the primary outcome; however, 40 mg provided moderate-to-strong evidence for positive effects on LDA and cocaine-negative UDS. The 40 mg dose was declared the "winner" in this DTL trial.

The effects of combination levodopa-ropinirole on cognitive improvement and treatment outcome in individuals with cocaine use disorder: A bayesian mediation analysis

BACKGROUND

Chronic cocaine users show impairments in cognitive processes associated with dopamine (DA) circuitry. Medications aimed at bolstering cognitive functions via DA modulation might enhance treatment outcome.

METHODS

The trial used a double-blind, double-dummy, parallel-group design with four treatment arms comparing placebo (PLC) to levodopa/carbidopa 800 mg/200 mg alone (LR0), levodopa plus extended release (XR) ropinirole 2 mg (LR2) or XR ropinirole 4 mg (LR4). Adults (n = 110) with cocaine use disorder attended thrice weekly clinic visits for 10 weeks. Potential cognitive mediators assessed at week 5 consisted of measures of decision-making (Iowa Gambling Task, Risky Decision-Making Task), attention/impulsivity (Immediate Memory Task), motivation (Progressive Ratio task), and cognitive control (Cocaine Stoop task). The primary outcome measure was the treatment effectiveness score (TES) calculated as the number of cocaine-negative urines collected from weeks 6-10.

RESULTS

Bayesian mediation examined indirect and total effects of the relationships between each active treatment (compared to PLC) and TES. Total (direct) effects were supported for LR0 and LR2, but not for LR4. Indirect effects were tested for each mediator. Notably, 22.3 % and 35.4 % of the total effects of LR0 and LR2 on TES were mediated by changes in attention/impulsivity.

CONCLUSIONS

The hypothesized mediation effect was strongest for levodopa plus 2 mg ropinirole, indicating that this DA medication combination predicted change (improvement) in attention/impulsivity, which in turn predicted change (reduction) in cocaine use. This finding provides modest support for cognitive enhancement as a target for medications to treat cocaine use disorder.

Exploring the relationship between white matter integrity, cocaine use and GAD polymorphisms using Bayesian Model Averaging

Past investigations utilizing diffusion tensor imaging (DTI) have demonstrated that cocaine use disorder (CUD) yields white matter changes, primarily in the corpus callosum. By applying Bayesian model averaging using multiple linear regression in DTI, we demonstrate there may exist relationships between the impaired white matter and glutamic acid decarboxylase (GAD) polymorphisms. This work explored the two-way and three-way interactions between GAD1a (SNP: rs1978340) and GAD1b (SNP: rs769390) polymorphisms and years of cocaine use (YCU). GAD1a was associated with more frontal white matter changes on its own but GAD1b was associated with more midbrain and cerebellar changes as well as a greater increase in white matter changes in the context of chronic cocaine use. The three-way interaction GAD1a|GAD1b|YCU appeared to be roughly an average of the polymorphism two-way interactions GAD1a|YCU and GAD1b|YCU. The three-way interaction demonstrated multiple regions including corpus callosum which featured fewer significant voxel changes, perhaps suggesting a small protective effect of having both polymorphisms on corpus callosum and cerebellar peduncle.

The Use of Once-monthly Injectable Buprenorphine for the Treatment of Opioid Use Disorder in Postpartum Women: A Case Series

OBJECTIVES

For women with opioid use disorder (OUD), the postpartum period is an especially vulnerable period. Buprenorphine (BUP) improves OUD outcomes during this timeframe. Once-monthly injectable BUP (XRI-BUP) is a newer formulation for which evidence of use in postpartum women is extremely limited. We present a case series of 9 women who transitioned from sublingual (SL-BUP) to XRI-BUP in their first year postpartum.

METHODS

We conducted a retrospective chart review of our institution's medical record for patients who received at least one administration of XRI-BUP in their first year postpartum (January 2017-March 2020). Data were collected from baseline through mean follow-up of 281.4 days (range 235-417) for participant outcomes.

RESULTS

The most common indications for initiating XRI-BUP were participant preference (n = 9) followed by challenges taking SL-BUP (n = 6). Four of the 9 participants transitioned back from XRI- to SL-BUP during the study timeframe, for reasons including incarceration and undesired side effects. Preliminary treatment outcomes demonstrated that participants remained on SL- (n = 4) or XRI-BUP (n = 5) through follow-up. The 5 participants who remained on XRI-BUP had consistent negative urine drug tests for nonprescribed opioids during the study period.

CONCLUSIONS

To our knowledge, this is the first study that reviews the feasibility of using XRI-BUP in postpartum women. Our results suggest that XRI-BUP is a viable treatment option, which should be further investigated in future studies of postpartum women with OUD.

Social Information Processing in Substance Use Disorders: Insights From an Emotional Go-Nogo Task

Positive social connections are crucial for recovery from Substance Use Disorder (SUD). Of interest is understanding potential social information processing (SIP) mediators of this effect. To explore whether persons with different SUD show idiosyncratic biases toward social signals, we administered an emotional go-nogo task (EGNG) to 31 individuals with Cocaine Use Disorder (CoUD), 31 with Cannabis Use Disorder (CaUD), 79 with Opioid Use Disorder (OUD), and 58 controls. Participants were instructed to respond to emotional faces (Fear/Happy) but withhold responses to expressionless faces in two task blocks, with the reverse instruction in the other two blocks. Emotional faces as non-targets elicited more "false alarm" (FA) commission errors as a main effect. Groups did not differ in overall rates of hits (correct responses to target faces), but participants with CaUD and CoUD showed reduced rates of hits (relative to controls) when expressionless faces were targets. OUD participants had worse hit rates [and slower reaction times (RT)] when fearful faces (but not happy faces) were targets. CaUD participants were most affected by instruction effects (respond/"go" vs withhold response/"no-go" to emotional face) on discriminability statistic A. Participants were faster to respond to happy face targets than to expressionless faces. However, this pattern was reversed in fearful face blocks in OUD and CoUD participants. This experiment replicated previous findings of the greater salience of expressive face images, and extends this finding to SUD, where persons with CaUD may show even greater bias toward emotional faces. Conversely, OUD participants showed idiosyncratic behavior in response to fearful faces suggestive of increased attentional disruption by fear. These data suggest a mechanism by which positive social signals may contribute to recovery.

Development and Feasibility Study of an Addiction-Focused Phenotyping Assessment Battery

BACKGROUND AND OBJECTIVES

Current methods of classifying individuals with substance use disorder (SUD) result in vast heterogeneity among persons within a given diagnosis. These approaches, while clinically allowing for distinctions between patient groups, are less than ideal when attempting to recruit a neurobehaviorally defined subset of subjects into clinical trials. To address this gap, alternative strategies have been proposed, including behavioral phenotyping. The NIDA Phenotyping Assessment Battery (PhAB) is a modular package of assessments and neurocognitive tasks that was developed for use in clinical trials. The goal of the present study is to assess the feasibility of the NIDA PhAB with regard to ease of administration and time burden.

METHODS

Healthy controls, persons with cocaine use disorder (CocUD), opioid use disorder (OUD), cannabis use disorder (CanUD), and combined opioid and cocaine use disorder (OCUD) were recruited from various sources (N = 595). Participants completed screening and one to three assessment visits. Time to complete the measures was recorded and a satisfaction interview was administered.

RESULTS

Of the participants enrolled, 381 were deemed eligible. The majority of eligible participants (83%) completed all assessments. The average completion time was 3 hours. High participant satisfaction ratings were noted, with over 90% of participants endorsing a willingness to participate in a similar study and recommend the study to others. CONCLUSION AND SCIENTIFIC SIGNIFICANCE: These findings corroborate the ease with which the PhAB may be easily incorporated into a study assessment visit without undue participant burden. The PhAB is an efficient method for behavioral phenotyping in addiction clinical trials. (Am J Addict 2021;00:00-00).

Clinical features and outcomes between African American and Caucasian patients with Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome (TS) is an acute, reversible form of heart failure, often mimicking an acute coronary syndrome (ACS). Data regarding racial differences in TS are inconsistent. The aim is to assess clinical features associated with unfavorable in-hospital outcomes between African American (AA) and Caucasian (CAU) patients.

METHODS

A retrospective electronic health record query identified 44 AA patients and 110 CAU patients with a diagnosis of TS. Our primary outcome was a composite of death, stroke, and cardiogenic shock during hospitalization. Variables associated with an increased risk of the primary composite outcomes were included in a logistic regression model.

RESULTS

Compared to CAU patients, AA patients were a more comorbid population, and presented a higher prevalence of history of illicit drug use (27.3% vs 13.6% p=0.044). There were no significant differences regarding in-hospital complication rates between AA and CAU patients. In the logistic regression model, infection was associated with greater risk of developing the primary outcome in AA patients (OR=7.26 95% CI [1.22-43.17], p=0.029), whereas angina was a protective factor (OR=0.11 95% CI [0.02-0.65], p=0.015). In CAU patients, severely depressed ejection fraction and worse peak creatinine during hospitalization increased risk of developing the primary outcome (OR=5.88 95% CI [2.01-17.17], p<0.001 and OR=1.64 95% CI [1.15-2.58], p=0.031, respectively). Meanwhile, emotional stressors were protective (OR=0.16 95% CI [0.03-0.88], p=0.004).

CONCLUSIONS

Despite experiencing the same rate of in-hospital complications, the clinical profiles of AA patients are distinct from CAU patients admitted for TS, and clinical variables correlated with worse in-hospital outcomes also differ by race.

Safety and Preliminary Efficacy of Lorcaserin for Cocaine Use Disorder: A Phase I Randomized Clinical Trial

Background and Objectives: Preclinical studies show serotonin (5-HT) 5-HT_2C receptor (5-HT_2CR) agonists reduce cocaine-seeking and cocaine intake. This study examined safety of the 5-HT_2CR agonist lorcaserin administered with cocaine in participants with cocaine use disorder (CocUD). Secondarily, subjective response to cocaine and choice of cocaine vs. money were examined. Methods: A double-blind, randomized, placebo-controlled trial of 25 inpatient non-treatment seeking participants with CocUD. Participants were randomized to either lorcaserin (n = 17) or placebo (n = 8). Primary outcome measures included cardiovascular measures and plasma cocaine levels. Secondary measures of subjective response to cocaine were assessed using a visual analog scale (VAS) and cocaine vs. money progressive ratio choice sessions. Results: Thirteen randomized participants were included in the final analysis. No serious or unexpected adverse events were related to lorcaserin. There were no significant interactions between cocaine and lorcaserin on cardiovascular measures, plasma cocaine, or subjective ratings. After multiple comparisons correction, cocaine significantly increased blood pressure, heart rate, and QTc. Lorcaserin significantly decreased VAS ratings of "feel irritable," "feel hungry," and "I am craving." For the cocaine vs. money choice procedure, there was a significant interaction between choice (cocaine vs. money) and lorcaserin. Participants treated with lorcaserin were more likely to choose cocaine. Discussion and Conclusions: This study showed safety of lorcaserin administered with cocaine but lack of efficacy to reduce the reinforcing effects of cocaine. Scientific Significance: This study is the first to show a disconnect between effects of 5-HT_2CR agonists on craving and cocaine choice in human cocaine users.

Blunted prefrontal signature of proactive inhibitory control in cocaine use disorder

BACKGROUND

Impulsivity is an established risk factor for substance use disorder (SUD). Integral to SUD recovery is proactive control (leveraging information about a potential need for behavioral restraint to marshal increased cognitive resources toward inhibition) when cues for drug use are unavoidable. However, proactive control is little studied in SUD, and is merely inferred from post-error performance adjustments.

METHODS

We probed covert neurocircuit signatures of proactive control in persons with SUD, as well as the moderating effects of incentives for successfully exerting proactive control. We administered a Monetary Incentive Stop Task (MIST) during functional magnetic resonance imaging of adults with cocaine use disorder (CUD; n = 21) and healthy controls (n = 21). The MIST blended the reward and loss-anticipatory cues of the Monetary Incentive Delay (MID) Task with a variant of the Stop-Signal Task, in which target color signaled whether or not withholding a response might be necessary.

RESULTS

In controls, but not in CUD participants, targets that signaled a potential need to stop (as a contrast with targets that signaled no need to stop) activated portions of right operculum akin to activation commonly elicited by stop signals, despite no actual stop signal. Across all participants, this proactive control activation did not relate to task behavior or to questionnaire impulsivity. Anticipatory incentive cues did not recruit ventral striatum.

CONCLUSIONS

These data suggest that persons with CUD show blunted covert signatures of attention and proactive control. This potentially accounts in part for the role of poor executive function in relapse vulnerability.

Nonfatal Opioid Overdoses at an Urban Emergency Department During the COVID-19 Pandemic

This study compares the numbers of nonfatal, unintentional opioid-related opioid overdoses presenting to a US urban emergency department during the early months of the coronavirus disease 2019 (COVID-19) pandemic (March-June 2020) vs 2019, overall and by age, race/ethnicity, and insurance status.

Resting-State Directional Connectivity and Anxiety and Depression Symptoms in Adult Cannabis Users

BACKGROUND

Anxiety and depression symptoms are common among cannabis users and could be a risk factor for cannabis use (CU) disorder. Thus, it is critical to understand the neuronal circuits underlying the associations between CU and these symptoms. Alterations in resting-state functional connectivity within and/or between the default mode network and salience network have been reported in CU, anxiety, and depressive disorders and thus could be a mechanism underlying the associations between CU disorder and anxiety/depression symptoms.

METHODS

Using resting-state functional magnetic resonance imaging, effective connectivities (ECs) among 9 major nodes from the default mode network and salience network were measured using dynamic causal modeling in 2 datasets: the Human Connectome Project (28 CU participants and 28 matched non-drug-using control participants) and a local CU study (21 CU participants and 21 matched non-drug-using control participants) in separate and parallel analyses.

RESULTS

Relative to the control participants, right amygdala to left amygdala, anterior cingulate cortex to left amygdala, and medial prefrontal cortex to right insula ECs were greater, and left insula to left amygdala EC was smaller in the CU group. Each of these ECs showed a reliable linear relationship with at least one of the anxiety/depression measures. Most findings on the right amygdala to left amygdala EC were common to both datasets.

CONCLUSIONS

Right amygdala to left amygdala and anterior cingulate cortex to left amygdala ECs may be related to the close associations between CU and anxiety/depression symptoms. The findings on the medial prefrontal cortex to right insula and left insula to left amygdala ECs may reflect a compensatory mechanism.

Examination of preliminary behavioral and effective connectivity findings from treatment response to citalopram in cocaine use disorder: A dynamic causal modeling study

We sought effective (directional) connectivity parameters associated with response to citalopram in cocaine use disorder (CUD) by conducting a functional magnetic resonance imaging (fMRI) experiment with participants diagnosed with CUD (n = 13) and matched healthy controls (HC; n = 17). CUD participants showed a positive correlation between bilateral DLPFC-to-putamen effective connectivity and treatment effectiveness score. These preliminary results support further investigation of prefrontal-striatal interactions in response to treatment in CUD.

Differences in heart rate among recent marijuana use groups

BACKGROUND

Marijuana use increases cardiac sympathetic activity within minutes of its use and this effect may begin to decrease as soon as one hour after marijuana use. However, the cardiovascular effects of marijuana use more than an hour after use is poorly characterized. The purpose of the current study is to compare heart rate, a marker of cardiac sympathetic activity, across recent marijuana use groups (never used: N.=63; recent use [in the past 24 hours; subacute] N.=13; in the past 7 days, but not in the past 24 hours: N.=17). Overall, the current sample included 93 African American/Black college students, with a mean age of 20.03±2.21 years.

METHODS

Participants completed a demographic form, a brief battery of psychological questionnaires, and had their heart rate assessed at baseline.

RESULTS

Analysis of covariance showed that heart rate was statistically significantly lower in the recent use group (62.38 bpm) compared with the non-users group (73.92 bpm). This difference persisted before and after statistically adjusting for demographic covariates.

CONCLUSIONS

These results suggest that there may be a cardiovascular process that occurs when using marijuana that results in a compensatory, reduced heart rate.

Differences in heart rate among recent marijuana use groups

BACKGROUND

Marijuana use increases cardiac sympathetic activity within minutes of its use and this effect may begin to decrease as soon as one hour after marijuana use. However, the cardiovascular effects of marijuana use more than an hour after use is poorly characterized. The purpose of the current study is to compare heart rate, a marker of cardiac sympathetic activity, across recent marijuana use groups (never used: N.=63; recent use [in the past 24 hours; subacute] N.=13; in the past 7 days, but not in the past 24 hours: N.=17). Overall, the current sample included 93 African American/Black college students, with a mean age of 20.03±2.21 years.

METHODS

Participants completed a demographic form, a brief battery of psychological questionnaires, and had their heart rate assessed at baseline.

RESULTS

Analysis of covariance showed that heart rate was statistically significantly lower in the recent use group (62.38 bpm) compared with the non-users group (73.92 bpm). This difference persisted before and after statistically adjusting for demographic covariates.

CONCLUSIONS

These results suggest that there may be a cardiovascular process that occurs when using marijuana that results in a compensatory, reduced heart rate.

The Impact of Parental Incarceration on Psychopathy, Crime, and Prison Violence in Women

There is a growing interest in understanding the consequences of parental incarceration. Unfortunately, research exploring the long-term criminological and personality effects in female offspring is limited, particularly among second-generation female offenders. In a sample of 170 female offenders, we first assessed the correlations between psychopathy facets, prison violence, and types of crime. Next, we tested the association between childhood exposure to paternal and/or maternal incarceration on adulthood psychopathic traits, criminal offending, and prospective prison violence over 12 months. Correlations showed the interpersonal facet was positively correlated with fraud-related crime and prison violence. The affective facet was positively correlated with violent crime and prison violence. The behavioral facet was associated with prison violence and drug-related crime. Multinomial logistic regressions showed higher interpersonal facet scores were associated with an increased likelihood of having experienced paternal incarceration. Higher affective facet scores, violent crime, and prison violence were associated with an increased likelihood of having experienced maternal incarceration, regardless of if the father had been incarcerated or not. It is evident that having any parent incarcerated during childhood can be harmful to daughters; however, our findings dovetail with prior research showing that maternal incarceration leads to more detrimental outcomes for women.

Buprenorphine dosing for the treatment of opioid use disorder through pregnancy and postpartum

Purpose of Review

Opioid-related deaths are a leading cause of mortality during pregnancy through 12 months postpartum. Buprenorphine use during pregnancy is increasing, yet expert opinion on its dosing through the perinatal period is limited. We provide a review of the current clinical literature on buprenorphine dosing during pregnancy through 12 months postpartum. and present data from a retrospective chart review of patients at our institution describing trends in buprenorphine dosing during pregnancy and postpartum. Utilizing this information, we synthesize findings to provide clinical recommendations for providers.

Recent Findings

Existing literature during pregnancy reflects how many women increase and split total daily buprenorphine doses as gestational age advances.

Summary

We present data from a retrospective chart review of patients at our institution describing trends in buprenorphine dosing during pregnancy and postpartum. Utilizing this information, we synthesize findings to provide clinical recommendations for providers. Changes in the total daily dose of buprenorphine used across pregnancy and through 12 months postpartum at the individual level do not follow consistent patterns, highlighting substantial individual variability. Altogether, buprenorphine dosing should be individualized through pregnancy and postpartum with frequent evaluations by providers and solicited input from patients.

Neurocognitive and Psychiatric Markers for Addiction: Common vs. Specific Endophenotypes for Heroin and Amphetamine Dependence

BACKGROUND

The differential utility of neurocognitive impulsivity and externalizing/ internalizing traits as putative endophenotypes for dependence on heroin vs. amphetamine is unclear.

OBJECTIVE

This exploratory study aims to determine: (1) whether neurocognitive impulsivity dimensions and externalizing/internalizing traits are correlated between siblings discordant for heroin and amphetamine dependence; and (2) which of these associations are common across substances and which are substance- specific.

METHODS

Pearson correlations between individuals with 'pure' heroin and amphetamine dependence and their unaffected biological siblings (n = 37 heroin sibling pairs; n = 30 amphetamine sibling pairs) were run on 10 neurocognitive measures, 6 externalizing measures, and 5 internalizing measures. Sibling pair effects were further examined using regression.

RESULTS

Siblings discordant for heroin dependence were significantly correlated on delay aversion on the Cambridge Gambling Task, risk-taking on the Balloon Analogue Risk Task, sensation seeking, and hopelessness. Siblings discordant for amphetamine dependence were significantly correlated on the quality of decision-making on the Cambridge Gambling Task, discriminability on the Immediate Memory Task, commission errors on the Go/No Go Task, trait impulsivity, ADHD and anxiety sensitivity.

CONCLUSION

Dimensions of impulsivity and externalizing/internalizing traits appear to aggregate among siblings discordant for substance dependence. Risk-taking propensity, sensation seeking and hopelessness were specific for heroin sibling pairs. Motor/action impulsivity, trait impulsivity, and anxiety sensitivity were specific to amphetamine sibling pairs. Decisional/choice impulsivity was common across both heroin and amphetamine sibling pairs. These findings provide preliminary evidence for the utility of neurocognitive impulsivity and externalizing/ internalizing traits as candidate endophenotypes for substance dependence in general and for substance-specific dependencies.

Methylation Patterns of the HTR2A Associate With Relapse-Related Behaviors in Cocaine-Dependent Participants

Relapse during abstinence in cocaine use disorder (CUD) is often hastened by high impulsivity (predisposition toward rapid unplanned reactions to stimuli without regard to negative consequences) and high cue reactivity (e.g., attentional bias towards drug reward stimuli). A deeper understanding of the degree to which individual biological differences predict or promote problematic behaviors may afford opportunities for clinical refinement and optimization of CUD diagnostics and/or therapies. Preclinical evidence implicates serotonin (5-HT) neurotransmission through the 5-HT_2A receptor (5-HT_2AR) as a driver of individual differences in these relapse-related behaviors. Regulation of 5-HT_2AR function occurs through many mechanisms, including DNA methylation of the HTR2A gene, an epigenetic modification linked with the memory of gene-environment interactions. In the present study, we tested the hypothesis that methylation of the HTR2A may associate with relapse-related behavioral vulnerability in cocaine-dependent participants versus healthy controls. Impulsivity was assessed by self-report (Barratt Impulsiveness Scale; BIS-11) and the delay discounting task, while levels of cue reactivity were determined by performance in the cocaine-word Stroop task. Genomic DNA was extracted from lymphocytes and the bisulfite-treated DNA was subjected to pyrosequencing to determine degree of methylation at four cytosine residues of the HTR2A promoter (-1439, -1420, -1224, -253). We found that the percent methylation at site -1224 after correction for age trended towards a positive correlation with total BIS-11 scores in cocaine users, but not healthy controls. Percent methylation at site -1420 negatively correlated with rates of delay discounting in healthy controls, but not cocaine users. Lastly, the percent methylation at site -253 positively correlated with attentional bias toward cocaine-associated cues. DNA methylation at these cytosine residues of the HTR2A promoter may be differentially associated with impulsivity or cocaine-associated environmental cues. Taken together, these data suggest that methylation of the HTR2A may contribute to individual differences in relapse-related behaviors in CUD.

Altered Effective Connectivity of Central Autonomic Network in Response to Negative Facial Expression in Adults With Cannabis Use Disorder

BACKGROUND

Cannabis use is associated with an increased risk of stress-related adverse cardiovascular events. Because brain regions of the central autonomic network largely overlap with brain regions related to the neural response to emotion and stress, the central autonomic network may mediate the autonomic response to negative emotional stimuli. We aimed to obtain evidence to determine whether neural connectivity of the central autonomic network is altered in individuals with cannabis use disorder (CUD) when they are exposed to negative emotional stimuli.

METHODS

Effective (directional) connectivity (EC) analysis using dynamic causal modeling was applied to functional magnetic resonance imaging data acquired from 23 subjects with CUD and 23 control subjects of the Human Connectome Project while they performed an emotional face-matching task with interleaving periods of negative-face (fearful/angry) and neutral-shape stimuli. The EC difference (modulatory change) was measured during the negative-face trials relative to the neutral-shape trials.

RESULTS

The CUD group was similar to the control group in nonimaging measures and brain activations but showed greater modulatory changes in left amygdala to hypothalamus EC (positively associated with Perceived Stress Scale score), right amygdala to bilateral fusiform gyri ECs (positively associated with Perceived Stress Scale score), and left ventrolateral prefrontal cortex to bilateral fusiform gyri ECs (negatively associated with Perceived Stress Scale score).

CONCLUSIONS

Left amygdala to hypothalamus EC and right amygdala to bilateral fusiform gyri ECs are possibly part of circuits underlying the risk of individuals with CUD to stress-related disorders. Correspondingly, left ventrolateral prefrontal cortex to bilateral fusiform gyri ECs are possibly part of circuits reflecting a protective mechanism.

Cingulo-hippocampal effective connectivity positively correlates with drug-cue attentional bias in opioid use disorder

Individuals with opioid use disorder (OUD) often relapse when exposed to opioid-related cues. Previous functional magnetic resonance imaging (fMRI) studies have identified neuronal corticolimbic changes related to drug cue reactivity in OUD. However, the corresponding manner in which brain regions interact is still unclear. Effective (directional) connectivity was analyzed using dynamic causal modeling of fMRI data acquired from 27 OUD participants (13 with OUD and 14 with OUD and cocaine use disorder [OUD+CUD]), while performing an opioid-word Stroop task. Participants were shown opioid and neutral words presented in different colors and were instructed to indicate word color but ignore word meaning. The effects of opioid words relative to neutral words on effective connectivity and on behavioral reaction time were defined as modulatory change and attentional bias, respectively. For all the 27 participants, left anterior cingulate cortex (ACC) to right hippocampus effective connectivity exhibited the largest modulatory change, which was positively correlated with attentional bias. The findings for the ACC to hippocampus EC were consistent across OUD and CUD found in a previous study.

Serotonin 5-HT2C Receptor Cys23Ser Single Nucleotide Polymorphism Associates with Receptor Function and Localization In Vitro

A non-synonymous single nucleotide polymorphism of the human serotonin 5-HT_2C receptor (5-HT_2CR) gene that converts a cysteine to a serine at amino acid codon 23 (Cys23Ser) appears to impact 5-HT_2CR pharmacology at a cellular and systems level. We hypothesized that the Cys23Ser alters 5-HT_2CR intracellular signaling via changes in subcellular localization in vitro. Using cell lines stably expressing the wild-type Cys23 or the Ser23 variant, we show that 5-HT evokes intracellular calcium release with decreased potency and peak response in the Ser23 versus the Cys23 cell lines. Biochemical analyses demonstrated lower Ser23 5-HT_2CR plasma membrane localization versus the Cys23 5-HT_2CR. Subcellular localization studies demonstrated O-linked glycosylation of the Ser23 variant, but not the wild-type Cys23, may be a post-translational mechanism which alters its localization within the Golgi apparatus. Further, both the Cys23 and Ser23 5-HT_2CR are present in the recycling pathway with the Ser23 variant having decreased colocalization with the early endosome versus the Cys23 allele. Agonism of the 5-HT_2CR causes the Ser23 variant to exit the recycling pathway with no effect on the Cys23 allele. Taken together, the Ser23 variant exhibits a distinct pharmacological and subcellular localization profile versus the wild-type Cys23 allele, which could impact aspects of receptor pharmacology in individuals expressing the Cys23Ser SNP.

Convergent neural connectivity in motor impulsivity and high-fat food binge-like eating in male Sprague-Dawley rats

Food intake is essential for survival, but maladaptive patterns of intake, possibly encoded by a preexisting vulnerability coupled with the influence of environmental variables, can modify the reward value of food. Impulsivity, a predisposition toward rapid unplanned reactions to stimuli, is one of the multifaceted determinants underlying the etiology of dysregulated eating and its evolving pathogenesis. The medial prefrontal cortex (mPFC) is a major neural director of reward-driven behavior and impulsivity. Compromised signaling between the mPFC and nucleus accumbens shell (NAcSh) is thought to underlie the cognitive inability to withhold prepotent responses (motor impulsivity) and binge intake of high-fat food (HFF) seen in binge eating disorder. To explore the relationship between motor impulsivity and binge-like eating in rodents, we identified high (HI) and low impulsive (LI) rats in the 1-choice serial reaction time task and employed a rat model of binge-like eating behavior. HFF binge rats consumed significantly greater calories relative to control rats maintained on continual access to standard food or HFF. HI rats repeatedly exhibited significantly higher bingeing on HFF vs. LI rats. Next, we employed dual viral vector chemogenetic technology which allows for the targeted and isolated modulation of ventral mPFC (vmPFC) neurons that project to the NAcSh. Chemogenetic activation of the vmPFC to NAcSh pathway significantly suppressed motor impulsivity and binge-like intake for high-fat food. Thus, inherent motor impulsivity and binge-like eating are linked and the vmPFC to NAcSh pathway serves as a 'brake' over both behaviors.

Regional differences in white matter integrity in stimulant use disorders: A meta-analysis of diffusion tensor imaging studies

BACKGROUND

Converging lines of evidence from diffusion tensor imaging (DTI) studies reveal significant alterations in white matter (WM) microstructure in the prefrontal cortex of chronic stimulant users compared to controls, suggesting compromised axonal microstructure and/or myelin.

METHODS

A meta-analysis of DTI-based WM integrity was conducted for white matter regions across the corpus callosum and association fibers. Articles were sourced and selected using PRISMA guidelines for systematic review and meta-analysis. Inclusion and exclusion criteria were determined by the authors in order to best capture WM integrity among individuals with primary stimulant use in comparison to healthy control subjects.

RESULTS

Eleven studies that focused on region-of-interest (ROI)-based analysis of WM integrity were extracted from an initial pool of 113 independent studies. Analysis across ROIs indicated significantly lower fractional anisotropy (FA) values in stimulant use groups compared to controls with a small to moderate overall effect (Hedges' g = -0.37, 95% CI [-0.54, -0.20]). Eigenvalues were also analyzed, revealing a significant effect for radial diffusivity (RD; Hedges' g = 0.24, 95% CI [0.01, 0.47]) but not axial diffusivity (AD; Hedges' g = 0.05, 95% CI [-0.20, 0.29]) or mean diffusivity (MD; Hedges' g = 0.20, 95% CI [-0.01, 0.41]). Subgroup analyses based on specific ROIs, primary substance use, poly-substance use, and imaging technology were also explored.

CONCLUSION

Results of the present study suggest a consistent effect of compromised WM integrity for individuals with stimulant use disorders. Furthermore, no significant differences were found between cocaine and methamphetamine-based groups.

Confirmed marijuana use and lymphocyte count in black people living with HIV

BACKGROUND

Marijuana is a commonly used recreational substance with purported analgesic and mood enhancing properties. Many people living with HIV identify marijuana as a palliative substance. However, through its main psychoactive component, tetrahydrocannabinol (THC), is known to influence the immune system. The effects of marijuana use in people with HIV are still controversial, with very scant literature in Black adults.

METHODS

The current study determined the differences in the lymphocyte count, specifically the number cluster differentiation 4 and 8 (CD4+ and CD8+), among patients who urine drug tested negative for THC (n = 70) and those who tested positive for THC (n = 25). The sample included 95 Black people living with HIV, 51% female, with a mean age of 46 ± 11 years. Participants provided a urine sample for substance use testing and a trained researcher extracted clinical data from clinical charts on the day of appointment.

RESULTS

After adjusting for demographic and HIV-related covariates, THC-positive patients had significantly higher CD4+ and CD8+ counts than their THC-negative counterparts.

CONCLUSION

These results extend previous HIV-related immunity findings in an underrepresented group, and suggest that THC use does not reduce immune function as measured by CD count. Further research is warranted on the overall effects of THC on immune function in HIV positive patients.

Utilizing Buprenorphine in the Emergency Department after Overdose

The United States is currently in the midst of an opioid epidemic. Barriers to treatment in the emergency department can lead to missed opportunities for helping prevent overdose and relapse in individuals with opioid use disorder. The administration of buprenorphine in the emergency department can potentially lead to better treatment outcomes for these individuals.

Rapid Separation and Quantitation of Cocaine and its Metabolites in Human Serum by Differential Mobility Spectrometry-tandem Mass Spectrometry (DMS-MS-MS)

Cocaine continues to be one of the most widespread abused illicit drugs in the USA. Rapid methods are needed for the identification and quantitation of cocaine and its metabolites, benzoylecgonine (BE), ecgonine methyl ester (EME) and cocaethylene (CE), in biological specimens by clinical and forensic toxicology laboratories. Presented is a differential ion mobility spectrometry-tandem mass spectrometry (DMS-MS-MS) method for the analysis of cocaine and its major metabolites in human serum that requires minimal sample preparation and no column chromatography. A Shimadzu Nexera X2 ultra-high performance liquid chromatography system was used to infuse the samples into the DMS cell at a rate of 30 μL/min. Separation of cocaine and its metabolites were performed in a SelexION DMS component from Sciex coupled to a QTRAP 6500 with an IonDrive Turbo V source for TurbolonSpray® using acetonitrile as a chemical modifier. Analysis consisted of ramping the CoV from -35 V to -6 V while monitoring the multiple reaction monitoring (MRM) transitions of each analyte. The assay was evaluated for linearity, bias, precision, carryover, interferences and stability. Calibration curves ranged from 10 to 1,000 ng/mL with linear regression correlation coefficients (r2) of 0.9912 or greater for each analyte. The limit of quantitation was set at 10 ng/mL. Intra-day precision (%CV) ranged from 0% to 15% for cocaine, 1% to 19% for BE, 1% to 17% for EME and 0% to 18% for CE. Inter-day precision ranged from 9% to 14% for cocaine, 2% to 17% for BE, 5% to 11% for EME and 5% to 15% for CE. No carryover or interferences were detected. Bland-Altman analysis of previously analyzed specimens by UPLC-MS-MS showed variability of 30% or less. The method demonstrates the applicability of DMS-MS-MS for high throughout analysis of drugs and their metabolites in clinical and forensic toxicology laboratories.