Providing medication for opioid use disorder and HIV pre-exposure prophylaxis at syringe services programs via telemedicine: a pilot study

BACKGROUND

People who inject drugs (PWID) are at high risk for opioid overdose and infectious diseases including HIV. We piloted PARTNER UP, a telemedicine-based program to provide PWID with medication for opioid use disorder (MOUD) with buprenorphine/naloxone (bup/nx) and oral pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate/emtricitabine through two syringe services programs (SSP) in North Carolina. We present overall results from this project, including participant retention rates and self-reported medication adherence.

METHODS

Study participants met with a provider for an initial in-person visit at the SSP, followed by weekly telemedicine visits in month 1 and then monthly until program end at month 6. Participants were asked to start both MOUD and PrEP at initiation but could choose to discontinue either at any point during the study. Demographics and health history including substance use, sexual behaviors, and prior use of MOUD/PrEP were collected at baseline. Follow-up surveys were conducted at 3- and 6-months to assess attitudes towards MOUD and PrEP, change in opioid use and sexual behaviors, and for self-reported medication adherence. Participant retention was measured by completion of visits; provider notes were used to assess whether the participant reported continuation of medication.

RESULTS

Overall, 17 persons were enrolled and started on both bup/nx and PrEP; the majority self-identified as white and male. At 3 months, 13 (76%) remained on study; 10 (77%) reported continuing with both MOUD and PrEP, 2 (15%) with bup/nx only, and 1 (8%) with PrEP only. At 6 months, 12 (71%) remained on study; 8 (67%) reported taking both bup/nx and PrEP, and 4 (33%) bup/nx only. Among survey participants, opioid use and HIV risk behaviors decreased. Nearly all reported taking bup/nx daily; however, self-reported daily adherence to PrEP was lower and declined over time. The most common reason for not continuing PrEP was feeling not at risk for acquiring HIV.

CONCLUSIONS

Our study results show that MOUD and PrEP can be successfully administered via telemedicine in SSPs. PrEP appears to be a lower priority for participants with decreased continuation and adherence. Low perception of HIV risk was a reason for not continuing PrEP, possibly mitigated by MOUD use. Future studies including helping identify PWID at highest need for PrEP are needed.

TRIAL REGISTRATION

Providing Suboxone and PrEP Using Telemedicine, NCT04521920. Registered 18 August 2020. https://clinicaltrials.gov/study/NCT04521920?term=mehri%20mckellar&rank=2 .

Cocaine Use Prediction With Tensor-Based Machine Learning on Multimodal MRI Connectome Data

This letter considers the use of machine learning algorithms for predicting cocaine use based on magnetic resonance imaging (MRI) connectomic data. The study used functional MRI (fMRI) and diffusion MRI (dMRI) data collected from 275 individuals, which was then parcellated into 246 regions of interest (ROIs) using the Brainnetome atlas. After data preprocessing, the data sets were transformed into tensor form. We developed a tensor-based unsupervised machine learning algorithm to reduce the size of the data tensor from 275 (individuals) × 2 (fMRI and dMRI) × 246 (ROIs) × 246 (ROIs) to 275 (individuals) × 2 (fMRI and dMRI) × 6 (clusters) × 6 (clusters). This was achieved by applying the high-order Lloyd algorithm to group the ROI data into six clusters. Features were extracted from the reduced tensor and combined with demographic features (age, gender, race, and HIV status). The resulting data set was used to train a Catboost model using subsampling and nested cross-validation techniques, which achieved a prediction accuracy of 0.857 for identifying cocaine users. The model was also compared with other models, and the feature importance of the model was presented. Overall, this study highlights the potential for using tensor-based machine learning algorithms to predict cocaine use based on MRI connectomic data and presents a promising approach for identifying individuals at risk of substance abuse.

Longitudinal changes in neurocognitive performance related to drug use intensity in a sample of persons with and without HIV who use illicit stimulants

BACKGROUND

Illicit stimulant use remains a public health concern that has been associated with multiple adverse outcomes, including cognitive deficits. The effects of stimulant use on cognition may be particularly deleterious in persons with HIV. Stimulant use intensity may be an important factor in the magnitude of observed deficits over time.

METHODS

We completed neurocognitive testing in a sample of people who use stimulants with (n = 84) and without HIV (n = 123) at baseline and up to 4 follow-up time points over approximately 1 year. Participants reported on substance use at each visit, including frequency of use and stimulant dependence. Mixed effects models examined the relationship between stimulant-related factors and neurocognitive function over time.

RESULTS

Participants were mostly male (57%), African American (86%), and 47.41 years old on average. All participants actively used stimulants at enrollment and use remained prevalent throughout the follow-up period, with an average of ≥24 days of use in the past 90 days at all time points. Retention was excellent, with 86% completing all 4 follow-up assessments. Mixed effects models showed that stimulant dependence was associated with lower neurocognitive performance independent of HIV status (p = 0.002), whereas frequency of use had a greater negative impact on performance in participants with HIV compared to those without HIV (p = 0.045).

CONCLUSIONS

Our key finding is that stimulant-related factors are associated with neurocognitive performance over time, but in complex ways. These findings have important implications for harm reduction approaches, particularly those that target cognitive function.

Cocaine use is associated with cerebral white matter hyperintensities in HIV disease

BACKGROUND

White matter hyperintensities (WMH), a marker of cerebral small vessel disease and predictor of cognitive decline, are observed at higher rates in persons with HIV (PWH). The use of cocaine, a potent central nervous system stimulant, is disproportionately common in PWH and may contribute to WMH.

METHODS

The sample included of 110 PWH on antiretroviral therapy. Fluid-attenuated inversion recovery (FLAIR) and T1-weighted anatomical MRI scans were collected, along with neuropsychological testing. FLAIR images were processed using the Lesion Segmentation Toolbox. A hierarchical regression model was run to investigate predictors of WMH burden [block 1: demographics; block 2: cerebrovascular disease (CVD) risk; block 3: lesion burden].

RESULTS

The sample was 20% female and 79% African American with a mean age of 45.37. All participants had persistent HIV viral suppression, and the median CD4+ T-cell count was 750. Nearly a third (29%) currently used cocaine regularly, with an average of 23.75 (SD = 20.95) days in the past 90. In the hierarchical linear regression model, cocaine use was a significant predictor of WMH burden (β = .28). WMH burden was significantly correlated with poorer cognitive function (r = -0.27). Finally, higher WMH burden was significantly associated with increased serum concentrations of interferon-γ-inducible protein 10 (IP-10) but lower concentrations of myeloperoxidase (MPO); however, these markers did not differ by COC status.

CONCLUSIONS

WMH burden is associated with poorer cognitive performance in PWH. Cocaine use and CVD risk independently contribute to WMH, and addressing these conditions as part of HIV care may mitigate brain injury underlying neurocognitive impairment.

HIV viremia contributes to neurocognitive impairments in persons who use cocaine

Persons with HIV (PWH) who use illicit drugs are at elevated risk for neurocognitive impairment (NCI). This study investigated the effects of HIV disease and HIV viremia on NCI among adults who use cocaine. PWH who were not virologically suppressed showed greater global deficits compared to participants with HIV viral suppression and HIV-negative participants, but no differences emerged between the latter two groups. These findings highlight the adverse effects of poorly controlled HIV disease on NCI, beyond the independent effects of cocaine on cognition, and underscore the importance of strengthening the HIV care continuum for persons who use cocaine.

Cortico-striatal networking deficits associated with advanced HIV disease and cocaine use

Cocaine use is disproportionately prevalent in people with HIV (PWH) and is known to potentiate HIV neuropathogenesis. As both HIV and cocaine have well-documented cortico-striatal effects, PWH who use cocaine and have a history of immunosuppression may exhibit greater FC deficits compared to PWH without these conditions. However, research investigating the legacy effects of HIV immunosuppression (i.e., a history of AIDS) on cortico-striatal functional connectivity (FC) in adults with and without cocaine use is sparse. Resting-state functional magnetic resonance imaging (fMRI) and neuropsychological assessment data from 273 adults were analyzed to examine FC in relation to HIV disease: HIV-negative (n = 104), HIV-positive with nadir CD4 ≥ 200 (n = 96), HIV-positive with nadir CD4 < 200 (AIDS; n = 73), and cocaine use (83 COC and 190 NON). Using independent component analysis/dual regression, FC was assessed between the basal ganglia network (BGN) and five cortical networks: dorsal attention network (DAN), default mode network, left executive network, right executive network, and salience network. There were significant interaction effects such that AIDS-related BGN-DAN FC deficits emerged in COC but not in NON participants. Independent of HIV, cocaine effects emerged in FC between the BGN and executive networks. Disruption of BGN-DAN FC in AIDS/COC participants is consistent with cocaine potentiation of neuro-inflammation and may be indicative of legacy HIV immunosuppressive effects. The current study bolsters previous findings linking HIV and cocaine use with cortico-striatal networking deficits. Future research should consider the effects of the duration of HIV immunosuppression and early treatment initiation.

Imaging of Brain Structural and Functional Effects in People With Human Immunodeficiency Virus

Before the introduction of antiretroviral therapy, human immunodeficiency virus (HIV) infection was often accompanied by central nervous system (CNS) opportunistic infections and HIV encephalopathy marked by profound structural and functional alterations detectable with neuroimaging. Treatment with antiretroviral therapy nearly eliminated CNS opportunistic infections, while neuropsychiatric impairment and peripheral nerve and organ damage have persisted among virally suppressed people with HIV (PWH), suggesting ongoing brain injury. Neuroimaging research must use methods sensitive for detecting subtle HIV-associated brain structural and functional abnormalities, while allowing for adjustments for potential confounders, such as age, sex, substance use, hepatitis C coinfection, cardiovascular risk, and others. Here, we review existing and emerging neuroimaging tools that demonstrated promise in detecting markers of HIV-associated brain pathology and explore strategies to study the impact of potential confounding factors on these brain measures. We emphasize neuroimaging approaches that may be used in parallel to gather complementary information, allowing efficient detection and interpretation of altered brain structure and function associated with suboptimal clinical outcomes among virally suppressed PWH. We examine the advantages of each imaging modality and systematic approaches in study design and analysis. We also consider advantages of combining experimental and statistical control techniques to improve sensitivity and specificity of biotype identification and explore the costs and benefits of aggregating data from multiple studies to achieve larger sample sizes, enabling use of emerging methods for combining and analyzing large, multifaceted data sets. Many of the topics addressed in this article were discussed at the National Institute of Mental Health meeting "Biotypes of CNS Complications in People Living with HIV," held in October 2021, and are part of ongoing research initiatives to define the role of neuroimaging in emerging alternative approaches to identifying biotypes of CNS complications in PWH. An outcome of these considerations may be the development of a common neuroimaging protocol available for researchers to use in future studies examining neurological changes in the brains of PWH.

Additive cortical gray matter deficits in people living with HIV who use cocaine

Cocaine use, which is disproportionately common in people living with HIV (PWH), is known to have neurotoxic effects that may exacerbate HIV neuropathogenesis. While both cocaine use and HIV disease are independently associated with deficits in gray matter (GM) volume, the additive effect of cocaine use to HIV disease on GM volume has not been explored. Here, we investigated subcortical and cortical brain volume differences between four groups of individuals with and without HIV disease and/or cocaine use. Participants also completed a comprehensive neuropsychological testing battery, and HIV disease characteristics were recorded. Within subcortical regions, cocaine use was independently associated with higher volume in the dorsal striatum and pallidum, while HIV disease was associated with lower volume in the nucleus accumbens and thalamus. For cortical regions, there was an additive effect of cocaine use on HIV disease in parietal and occipital lobe volume with PWH who used cocaine displaying the lowest GM volume. Within regions that differed between groups, higher neurocognitive function was positively associated with thalamic, nucleus accumbens, dorsal striatum, and occipital lobe volume. For regions that showed a significant main effect of HIV disease, lower nadir CD4 + T cell count was associated with lower nucleus accumbens and occipital lobe volume. Lower current CD4 + T cell count was associated with lower occipital lobe volume. These results suggest that PWH who use cocaine are at greater risk for cortical atrophy than cocaine use or HIV disease alone.

Neuroimaging and immunological features of neurocognitive function related to substance use in people with HIV

This study sought to identify neuroimaging and immunological factors associated with substance use and that contribute to neurocognitive impairment (NCI) in people with HIV (PWH). We performed cross-sectional immunological phenotyping, neuroimaging, and neurocognitive testing on virally suppressed PWH in four substance groups: cocaine only users (COC), marijuana only users (MJ), dual users (Dual), and Non-users. Participants completed substance use assessments, multimodal MRI brain scan, neuropsychological testing, and blood and CSF sampling. We employed a two-stage analysis of 305 possible biomarkers of cognitive function associated with substance use. Feature reduction (Kruskal Wallis p-value < 0.05) identified 53 biomarkers associated with substance use (22 MRI and 31 immunological) for model inclusion along with clinical and demographic variables. We employed eXtreme Gradient Boosting (XGBoost) with these markers to predict cognitive function (global T-score). SHapley Additive exPlanations (SHAP) values were calculated to rank features for impact on model output and NCI. Participants were 110 PWH with sustained HIV viral suppression (33 MJ, 12 COC, 22 Dual, and 43 Non-users). The ten highest ranking biomarkers for predicting global T-score were 4 neuroimaging biomarkers including functional connectivity, gray matter volume, and white matter integrity; 5 soluble biomarkers (plasma glycine, alanine, lyso-phosphatidylcholine (lysoPC) aC17.0, hydroxy-sphingomyelin (SM.OH) C14.1, and phosphatidylcholinediacyl (PC aa) C28.1); and 1 clinical variable (nadir CD4 count). The results of our machine learning model suggest that substance use may indirectly contribute to NCI in PWH through both metabolomic and neuropathological mechanisms.

The Individualized Prediction of Neurocognitive Function in People Living with HIV Based on Clinical and Multimodal Connectome Data

Neurocognitive impairment continues to be common comorbidity for people living with HIV (PLWH). Given the chronic nature of HIV disease, identifying reliable biomarkers of these impairments is essential to advance our understanding of the underlying neural foundation and facilitate screening and diagnosis in clinical care. While neuroimaging provides immense potential for such biomarkers, to date, investigations in PLWH have been mostly limited to either univariate mass techniques or a single neuroimaging modality. In the present study, connectome-based predictive modeling (CPM) was proposed to predict individual differences of cognitive functioning in PLWH, using resting-state functional connectivity (FC), white matter structural connectivity (SC), and clinical relevant measures. We also adopted an efficient feature selection approach to identify the most predictive features, which achieved an optimal prediction accuracy of r = 0.61 in the discovery dataset (n = 102) and r = 0.45 in an independent validation HIV cohort (n = 88). Two brain templates and nine distinct prediction models were also tested for better modeling generalizability. Results show that combining multimodal FC and SC features enabled higher prediction accuracy of cognitive scores in PLWH, while adding clinical and demographic metrics may further improve the prediction by introducing complementary information, which may help better evaluate the individual-level cognitive performance in PLWH.

Participant perceptions on the acceptability and feasibility of a telemedicine-based HIV PrEP and buprenorphine/naloxone program embedded within syringe services programs: a qualitative descriptive evaluation

BACKGROUND

People who inject drugs (PWID) are at risk for HIV and opioid overdose. We piloted PARTNER UP, a telemedicine-based program to provide PWID with access to both oral pre-exposure prophylaxis (PrEP) for HIV prevention and medication for opioid use disorder (MOUD) through two syringe services programs (SSPs) in North Carolina. We conducted a qualitative evaluation to assess the acceptability and feasibility of PARTNER UP from the participant perspective.

METHODS

PARTNER UP participants met with a provider for an initial in-person visit at the SSP, followed by weekly telemedicine visits in month 1 and then monthly telemedicine visits until program end at month 6. Using a qualitative descriptive study design, we conducted in-depth interviews with a subsample of PARTNER UP participants at 1 month and 4 months. Informed by the technology acceptance model, we assessed participant perceptions of the usefulness and ease of use of PARTNER UP, as well as their intent to continue to use the program's components. We audio-recorded all interviews with participants' permission and used applied thematic analysis to analyze the verbatim transcripts.

RESULTS

We interviewed 11 of 17 people who participated in PARTNER UP-10 in the month 1 interview and 8 in the month 4 interview. Nearly all participants were motivated to join for consistent and easy access to buprenorphine/naloxone (i.e., MOUD); only a few joined to access PrEP. Most were comfortable accessing healthcare at the SSP because of their relationship with and trust toward SSP staff, and accessing services at the SSP was preferred compared with other healthcare centers. Some participants described that telemedicine allowed them to be honest and share more information because the visits were not in-person and they chose the location, although the initial in-person meeting was helpful to build provider trust and rapport. Most participants found the visit schedule to be feasible, although half described needing to reschedule at least once. Nearly all participants who were interviewed intended to continue with MOUD after the program ended, whereas none were interested in continuing with PrEP.

CONCLUSIONS

Participant narratives suggest that the PARTNER UP telemedicine program was acceptable and feasible. Future studies should continue to explore the benefits of embedding both PrEP and MOUD into SSPs with larger numbers of participants. Trial registration Clinicaltrials.gov Identifier: NCT04521920.

Strengthened and posterior-shifted structural rich-club organization in people who use cocaine

BACKGROUND

People with cocaine use disorder (CUD) often have abnormal cognitive function and brain structure. Cognition is supported by brain networks that typically have characteristics like rich-club organization, which is a group of regions that are highly connected across the brain and to each other, and small worldness, which is a balance between local and long-distance connections. However, it is unknown whether there are abnormalities in structural brain network connectivity of CUD.

METHODS

Using diffusion-weighted imaging, we measured structural connectivity in 37 people with CUD and 38 age-matched controls. We identified differences in rich-club organization and whether such differences related to small worldness and behavior. We also tested whether rich-club reorganization was associated with caudate and putamen structural connectivity due to the relevance of the dopamine system to cocaine use.

RESULTS

People with CUD had a higher normalized rich-club coefficient than controls, more edges connecting rich-club nodes to each other and to non-rich-club nodes, and fewer edges connecting non-rich-club nodes. Rich-club nodes were shifted posterior and lateral. Rich-club reorganization was related to lower clustered connectivity around individual nodes found in CUD, to increased impulsivity, and to a decrease in caudate connectivity.

CONCLUSIONS

These findings are consistent with previous work showing increased rich-club connectivity in conditions associated with a hypofunctional dopamine system. The posterior shift in rich-club nodes in CUD suggests that the structural connectivity of posterior regions may be more impacted than previously recognized in models based on brain function and morphology.

Principal component analysis denoising improves sensitivity of MR diffusion to detect white matter injury in neuroHIV

BACKGROUND AND PURPOSE

Diffusion-weighted imaging is able to capture important information about cerebral white matter (WM) structure. However, diffusion data can suffer from MRI and biological noise that degrades the quality of the images and makes finding important features difficult. We investigated how effectively local and nonlocal denoising increased the sensitivity to detect differences in cerebral WM in neuroHIV.

METHODS

We utilized principal component analysis (PCA) denoising to detect WM differences using fractional anisotropy. Local and nonlocal PCA denoising paradigms were implemented that varied in search area and number of components. We examined different-sized WM tracts that consistently show differences between people living with Human Immunodeficiency Virus (HIV) (PWH) and HIV-negative individuals (corpus callosum, forceps minor, and right uncinate fasciculus), and size-matched tracts not typically associated with HIV-related differences (spinothalamic, right medial lemniscus, and left occipitopontine). We first conducted a full sample comparison of WM differences between groups, and then randomly reduced the sample to the point where we still found differences in WM.

RESULTS

Nonlocal PCA denoising allowed us to detect differences after a sample reduction of 35% in the forceps minor, 17% in the right uncinate fasciculus, and 6% in the corpus callosum.

CONCLUSIONS

PCA denoising had a beneficial effect on detecting significant differences in PWH after sample size reduction. The smaller forceps minor tract and right uncinate fasciculus showed greater sensitivity to PCA denoising than the larger corpus callosum. These results show the importance of identifying the most effective PCA denoising strategy when investigating WM in PWH.

Transmission Of Tuberculosis Among illicit drug use Linkages (TOTAL): A cross-sectional observational study protocol using respondent driven sampling

People who use illicit drugs (PWUDs) have been identified as a key at-risk group for tuberculosis (TB). Examination of illicit drug use networks has potential to assess the risk of TB exposure and disease progression. Research also is needed to assess mechanisms for accelerated TB transmission in this population. This study aims to 1) assess the rate of TB exposure, risk of disease progression, and disease burden among PWUD; 2) estimate the proportion of active TB cases resulting from recent transmission within this network; and 3) evaluate whether PWUD with TB disease have physiologic characteristics associated with more efficient TB transmission. Our cross-sectional, observational study aims to assess TB transmission through illicit drug use networks, focusing on methamphetamine and Mandrax (methaqualone) use, in a high TB burden setting and identify mechanisms underlying accelerated transmission. We will recruit and enroll 750 PWUD (living with and without HIV) through respondent driven sampling in Worcester, South Africa. Drug use will be measured through self-report and biological measures, with sputum specimens collected to identify TB disease by Xpert Ultra (Cepheid) and mycobacterial culture. We will co-enroll those with microbiologic evidence of TB disease in Aim 2 for molecular and social network study. Whole genome sequencing of Mycobacteria tuberculosis (Mtb) specimens and social contact surveys will be done for those diagnosed with TB. For Aim 3, aerosolized Mtb will be compared in individuals with newly diagnosed TB who do and do not smoke illicit drug. Knowledge from this study will provide the basis for a strategy to interrupt TB transmission in PWUD and provide insight into how this fuels overall community transmission. Results have potential for informing interventions to reduce TB spread applicable to high TB and HIV burden settings. Trial registration: Clinicaltrials.gov Registration Number: NCT041515602. Date of Registration: 5 November 2019.

Effects of substance use on monetary delay discounting among people who use stimulants with and without HIV: An ecological momentary assessment study

Exploration of the real-time relationship between substance use and delay discounting may reveal potential mechanisms driving high-risk behaviors. We conducted an ecological momentary assessment (EMA) study to investigate the effects of substance use on delay discounting in a sample of people who use stimulants (HIV+: 30; HIV-: 34). Participants completed multiple EMAs throughout the day for 28 days. The EMAs collected data on delay discounting and substance use (time since last substance use and level of intoxication). Delay discounting was assessed using a brief Monetary Choice Questionnaire (MCQ). Analyses were conducted using linear mixed effects modeling. Most participants (99.1%) used cocaine as their primary stimulant. Among participants without HIV, MCQ score remained relatively stable during the first 2 hr after stimulant use, followed by an increase during 2-6 hr (p < .05), before decreasing again. For alcohol and marijuana, the MCQ score was stable during the first 4 hr after use, with a sharp increase at 4-6 hr (p < .05), before decreasing again. Among participants with HIV, there were no changes in MCQ score as a function of time since recent substance use. These findings provide evidence of a plausible connection between delay discounting and acute withdrawal that may have relevance for risky behaviors. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

HIV, psychological resilience, and substance misuse during the COVID-19 pandemic: A multi-cohort study

OBJECTIVE

The COVID-19 pandemic has dramatically impacted mental health, increasing rates of substance misuse. Resilience is a positive adaptation to stress that may act as a buffer against adverse mental health outcomes. Based on prior knowledge, we hypothesized that PLWH would display higher resilience than HIV-uninfected peers, and that high resilience would be associated with lower risk of substance misuse.

METHODS

This analysis of the Collaborating Consortium of Cohorts Producing NIDA Opportunities (C3PNO) included data from six USA cohorts that administered a COVID-19-related survey with a 3-month follow-up during May 2020 and March 2021. All data was self-reported. The Brief Resilience Scale and General Anxiety Disorder-7 were utilized. Primary analyses consisted of multivariate generalized linear mixed models with random intercepts using binary logistic regression.

RESULTS

A total of 1430 participants completed both surveys, of whom 670 (46.9%) were PLWH. PLWH had lower odds of anxiety (OR=0.67, 95% CI: 0.51-0.89) and higher odds of high resilience (OR=1.21, 95% CI: 1.02-1.44) than HIV-uninfected participants, adjusted for covariates. The presence of anxiety was associated with higher risk of misuse of all substances. High resilience was associated with lower risk of anxiety and misuse of substances, adjusted for covariates.

CONCLUSIONS

Psychological resilience was associated with lower risk of anxiety and substance misuse, potentially serving as a buffer against poor mental and behavioral health during the COVID-19 pandemic. Further research is needed to identify pathways of resilience in the context of substance misuse and comprehensive resilience-focused interventions.

Human immunodeficiency virus-related decreases in corpus callosal integrity and corresponding increases in functional connectivity

People living with human immunodeficiency virus (PLWH) often have neurocognitive impairment. However, findings on HIV-related differences in brain network function underlying these impairments are inconsistent. One principle frequently absent from these reports is that brain function is largely emergent from brain structure. PLWH commonly have degraded white matter; we hypothesized that functional communities connected by degraded white matter tracts would show abnormal functional connectivity. We measured white matter integrity in 69 PLWH and 67 controls using fractional anisotropy (FA) in 24 intracerebral white matter tracts. Then, among tracts with degraded FA, we identified gray matter regions connected to these tracts and measured their functional connectivity during rest. Finally, we identified cognitive impairment related to these structural and functional connectivity systems. We found HIV-related decreased FA in the corpus callosum body (CCb), which coordinates activity between the left and right hemispheres, and corresponding increases in functional connectivity. Finally, we found that individuals with impaired cognitive functioning have lower CCb FA and higher CCb functional connectivity. This result clarifies the functional relevance of the corpus callosum in HIV and provides a framework in which abnormal brain function can be understood in the context of abnormal brain structure, which may both contribute to cognitive impairment.

Structural and Functional Brain Abnormalities in Human Immunodeficiency Virus Disease Revealed by Multimodal Magnetic Resonance Imaging Fusion: Association With Cognitive Function

BACKGROUND

Human immunodeficiency virus (HIV)-associated neurocognitive impairment remains a prevalent comorbidity that impacts daily functioning and increases morbidity. While HIV infection is known to cause widespread disruptions in the brain, different magnetic resonance imaging (MRI) modalities have not been effectively integrated. In this study, we applied 3-way supervised fusion to investigate how structural and functional coalterations affect cognitive function.

METHODS

Participants (59 people living with HIV and 58 without HIV) completed comprehensive neuropsychological testing and multimodal MRI scanning to acquire high-resolution anatomical, diffusion-weighted, and resting-state functional images. Preprocessed data were reduced using voxel-based morphometry, probabilistic tractography, and regional homogeneity, respectively. We applied multimodal canonical correlation analysis with reference plus joint independent component analysis using global cognitive functioning as the reference.

RESULTS

Compared with controls, participants living with HIV had lower global cognitive functioning. One joint component was both group discriminating and correlated with cognitive function. This component included the following covarying regions: fractional anisotropy in the corpus callosum, short and long association fiber tracts, and corticopontine fibers; gray matter volume in the thalamus, prefrontal cortex, precuneus, posterior parietal regions, and occipital lobe; and functional connectivity in frontoparietal and visual processing regions. Component loadings for fractional anisotropy also correlated with immunosuppression.

CONCLUSIONS

These results suggest that coalterations in brain structure and function can distinguish people with and without HIV and may drive cognitive impairment. As MRI becomes more commonplace in HIV care, multimodal fusion may provide neural biomarkers to support diagnosis and treatment of cognitive impairment.

On the down-sampling of diffusion MRI data along the angular dimension

BACKGROUND

It has been established that the diffusion gradient directions in diffusion MRI should be uniformly distributed in 3D spherical space, so that orientation-dependent diffusion properties (e.g., fractional anisotropy or FA) can be properly quantified. Sometimes the acquired data need to be down-sampled along the angular dimension before computing diffusion properties (e.g., to exclude data points corrupted by motion artifact; to harmonize data obtained with different protocols). It is important to quantitatively assess the impact of data down-sampling on measurement of diffusion properties.

MATERIALS AND METHODS

Here we report 1) a numerical procedure for down-sampling diffusion MRI (e.g., for data harmonization), and 2) a spatial uniformity index of diffusion directions, aiming to predict the quality of the chosen down-sampling schemes (e.g., from data harmonization; or rejection of motion corrupted data points). We quantitatively evaluated human diffusion MRI data, which were down-sampled from 64 or 60 diffusion gradient directions to 30 directions, in terms of their 1) FA value accuracy (using fully-sampled data as the ground truth), 2) FA fitting residuals, and 3) spatial uniformity indices.

RESULTS

Our experimental data show that the proposed spatial uniformity index is correlated with errors in FA obtained from down-sampled diffusion MRI data. The FA fitting residuals that are typically used to assess diffusion MRI quality are not correlated with either FA errors or spatial uniformity index.

CONCLUSIONS

These results suggest that the spatial uniformity index could be more valuable in assessing quality of down-sampled diffusion MRI data, as compared with FA fitting residual measures. We expect that our implemented software procedure should prove valuable for 1) guiding data harmonization for multi-site diffusion MRI studies, and 2) assessing the impact of rejecting motion corrupted data points on the accuracy of diffusion measures.

Brain multimodal co-alterations related to delay discounting: a multimodal MRI fusion analysis in persons with and without cocaine use disorder

BACKGROUND

Delay discounting has been proposed as a behavioral marker of substance use disorders. Innovative analytic approaches that integrate information from multiple neuroimaging modalities can provide new insights into the complex effects of drug use on the brain. This study implemented a supervised multimodal fusion approach to reveal neural networks associated with delay discounting that distinguish persons with and without cocaine use disorder (CUD).

METHODS

Adults with (n = 35) and without (n = 37) CUD completed a magnetic resonance imaging (MRI) scan to acquire high-resolution anatomical, resting-state functional, and diffusion-weighted images. Pre-computed features from each data modality included whole-brain voxel-wise maps for gray matter volume, fractional anisotropy, and regional homogeneity, respectively. With delay discounting as the reference, multimodal canonical component analysis plus joint independent component analysis was used to identify co-alterations in brain structure and function.

RESULTS

The sample was 58% male and 78% African-American. As expected, participants with CUD had higher delay discounting compared to those without CUD. One joint component was identified that correlated with delay discounting across all modalities, involving regions in the thalamus, dorsal striatum, frontopolar cortex, occipital lobe, and corpus callosum. The components were negatively correlated with delay discounting, such that weaker loadings were associated with higher discounting. The component loadings were lower in persons with CUD, meaning the component was expressed less strongly.

CONCLUSIONS

Our findings reveal structural and functional co-alterations linked to delay discounting, particularly in brain regions involved in reward salience, executive control, and visual attention and connecting white matter tracts. Importantly, these multimodal networks were weaker in persons with CUD, indicating less cognitive control that may contribute to impulsive behaviors.

Using mobile health technologies to test the association of cocaine use with sexual desire and risky sexual behaviors among people with and without HIV who use illicit stimulants

BACKGROUND

Cocaine use is broadly associated with risky sexual behavior potentially through elevated sexual desire. Understanding the within-person effects of cocaine on sexual desire and risky sexual behavior and the modification of HIV infection may inform primary and secondary HIV interventions.

METHODS

We conducted a mobile health (mHealth) study in a community sample of males and females with (n = 28) and without (n = 32) HIV who use illicit stimulant drugs. Participants completed ecological momentary assessments (EMAs) and daily diaries over 28 days. Mixed effects models were employed to examine the within-person association of cocaine use with sexual desire and risky sexual behavior.

RESULTS

Participants completed 3505 EMA responses, with 36 % involving recent cocaine use, including powder and/or crack cocaine. They completed 1427 daily diary responses, with cocaine use reported on 49 % of these days and sexual behavior on 21 % of these days. Sexual desire was highest in the first hour since cocaine use and gradually decreased with time. Sexual desire was lowest when participants had not used any cocaine in the past 6 h, and it correlated positively with the amount of use. Participants were more likely to have risky sexual behavior on days they used cocaine. These associations were similar for participants with and without HIV.

CONCLUSION

This study demonstrates the dynamic and proximal effects of cocaine use on sexual desire and risky sexual behavior. Our findings support the development of HIV prevention interventions that utilize mHealth technology to reduce sexual risk behavior among persons who use stimulant drugs.

Hypoactivation in the precuneus and posterior cingulate cortex during ambiguous decision making in individuals with HIV

People with human immunodeficiency virus (HIV) often have neurocognitive impairment. People with HIV make riskier decisions when the outcome probabilities are known, and have abnormal neural architecture underlying risky decision making. However, ambiguous decision making, when the outcome probabilities are unknown, is more common in daily life, but the neural architecture underlying ambiguous decision making in people with HIV is unknown. Eighteen people with HIV and 20 controls completed a decision making task while undergoing functional magnetic resonance imaging scanning. Participants chose between a certain reward and uncertain reward with a known (risky) or unknown (ambiguous) probability of winning. There were three levels of risk: high, medium, and low. Ambiguous > risky brain activity was compared between groups. Ambiguous > risky brain activity was correlated with emotional/psychiatric functioning in people with HIV. Both groups were similarly ambiguity-averse. People with HIV were more risk-averse than controls and chose the high-risk uncertain option less often. People with HIV had hypoactivity in the precuneus, posterior cingulate cortex (PCC), and fusiform gyrus during ambiguous > medium risk decision making. Ambiguous > medium risk brain activity was negatively correlated with emotional/psychiatric functioning in individuals with HIV. To make ambiguous decisions, people with HIV underrecruit key regions of the default mode network, which are thought to integrate internally and externally derived information to come to a decision. These regions and related cognitive processes may be candidates for interventions to improve decision-making outcomes in people with HIV.

Perceived Healthcare Access among Persons with and without HIV Who Use Illicit Stimulants: The Role of Cumulative Risk

Background: Persons who use stimulant drugs have greater morbidity and mortality relative to non-users. HIV infection has the potential to contribute to even great disparity in health outcomes among persons who use stimulants. These health disparities likely result in part due to poorer access to healthcare. Our study used a cumulative risk model to examine the impact of multiple risk factors on healthcare access in a sample of persons with and without HIV who use stimulants. Method: Our sample included 453 persons who reported recent use of illicit stimulants (102 HIV+, 351 HIV-). Participants completed clinical interviews, questionnaires, and a rapid oral HIV test. We constructed an 8-item cumulative risk index that included factors related to socioeconomic status, homelessness, legal history, and substance use. Results: Participants with HIV (PHW) were older than participants without HIV and more likely to have health insurance. Participants with and without HIV reported similar prior treatment utilization, but PWH reported better healthcare access and lower cumulative risk scores. Regression analyses showed cumulative risk was a significant predictor of healthcare access (β = -0.20, p < 0.001) even after controlling for age, HIV status, and health insurance status. We did not observe an interaction of HIV status by cumulative risk. Conclusions: Access to care among persons who use stimulants, both with and without HIV, is negatively impacted by the accumulation of risk factors from a number of different domains. Understanding the cumulative effects of these factors is critical for developing interventions to facilitate access to care, thus reducing health disparities and improving health outcomes.

Web-Based Cognitive Training to Improve Working Memory in Persons with Co-Occurring HIV Infection and Cocaine Use Disorder: Outcomes from a Randomized Controlled Trial

Neurocognitive impairment (NCI) remains a persistent complication of HIV disease that nearly half of persons with HIV experience, and rates are even higher in persons who use substances such as cocaine. Cognitive training is a promising intervention for HIV-associated NCI. In this randomized controlled trial, we examined the feasibility and effectiveness of a web-based cognitive training program to improve working memory in a sample of 58 persons with HIV and cocaine use disorder. Participants were randomly assigned to either the experimental working memory training arm or the attention control training arm and completed up to 48 daily sessions over 10 weeks. Overall, treatment completion (74%) and retention rates (97%) were high, and participant feedback indicated the intervention was acceptable. Our results show that the intervention successfully reduced working memory deficits in the experimental arm relative to the control arm. Our findings support both the feasibility and effectiveness of cognitive training in this population.

Examining the Potential of Pre-exposure Prophylaxis (PrEP) for HIV Prevention in a Community Sample of Persons Who Use Stimulants Living in the Southern United States

Pre-exposure prophylaxis (PrEP), a highly effective HIV prevention strategy, is currently underutilized by several at-risk groups, including both persons who inject drugs and those who use drugs via other routes. Stimulant use is associated with increased HIV risk due to both sexual and injection risk behaviors. In this study, we examined PrEP awareness and acceptability in persons with biologically confirmed HIV-negative status who use stimulant drugs. We also examined HIV risk behaviors to identify how many participants met behavioral eligibility for PrEP. The sample of 352 participants was 46% female, 87% African American, and 45.69 years old on average. Over half the sample (n = 213) met criteria for PrEP candidacy, but less than 20% had heard of PrEP. Ratings for willingness to take PrEP were high. PrEP candidates reported more frequent and problematic stimulant use relative to non-candidates. Our results show that persons who use stimulants are a high-risk population that could benefit significantly from PrEP. Efforts to increase PrEP awareness among high-risk populations are critical for facilitating PrEP implementation and ensuring effective HIV prevention within these communities.

Food Insecurity and Cognitive Impairment in the Miami Adult Studies on HIV (MASH) Cohort

BACKGROUND

Food insecurity is a social determinant of health associated with cognitive impairments in older adults and people living with HIV (PLWH). Few studies have examined this relation longitudinally, and no studies have explored how the frequency of food insecurity over time may impact cognitive impairment.

OBJECTIVE

This study aimed to examine the impact of food insecurity on cognitive impairment over a 2-y follow-up period in a cohort of people living with and without HIV.

METHODS

This was a 2-y longitudinal analysis of primarily economically disadvantaged, middle-aged, Black, and Hispanic participants from the Miami Adult Studies on HIV (MASH) cohort. Food insecurity was assessed with the USDA Household Food Security Module at baseline and 12- and 24-mo follow-ups. Food insecurity in all 3 assessments was considered persistent food insecurity. Cognitive impairment was assessed with the Mini-Mental State Examination. Statistical analyses consisted of logistic regressions.

RESULTS

A total of 394 participants (247 HIV positive) with 2-y follow-up data were included in this analysis. At baseline, 104 (26.4%) were food-insecure and 58 (14.7%) had cognitive impairment. Very low food security was associated with cognitive impairment at baseline (OR: 3.23; 95% CI: 1.08, 9.65). PLWH not virally suppressed had higher risk for cognitive impairment compared with HIV-uninfected participants (OR: 2.87; 95% CI: 1.15, 7.18). Additionally, baseline food insecurity (OR: 2.28; 95% CI: 1.08, 4.81) and the frequency of food insecurity over time (OR: 1.50 per year; 95% CI: 1.08, 2.10), particularly persistent food insecurity (OR: 3.69; 95% CI: 1.15, 11.83), were associated with cognitive impairment at 2-y follow-up; the results were consistent after excluding cognitively impaired participants at baseline.

CONCLUSIONS

Food insecurity is a significant risk factor for cognitive impairment, particularly among individuals who experience food insecurity frequently or persistently. Screening for food insecurity and interventions to secure access to sufficient, nutritious foods may help delay cognitive decline among socioeconomically disadvantaged individuals.

Experiences With Smoking Cessation Attempts and Prior Use of Cessation Aids in Smokers With HIV: Findings From a Focus Group Study Conducted in Durham, North Carolina

Cigarette smoking remains disproportionately prevalent and is increasingly a cause of death and disability among people with HIV (PWH). Many PWH are interested in quitting, but interest in and uptake of first-line smoking cessation pharmacotherapies are varied in this population. To provide current data regarding experiences with and perceptions of smoking cessation and cessation aids among PWH living in Durham, North Carolina, the authors conducted five focus group interviews (total n = 24; 96% African American) using semistructured interviews. Interviews were recorded, transcribed, coded, and thematically analyzed. Major themes included ambivalence and/or lack of interest in cessation; presence of cessation barriers; perceived perceptions of ineffectiveness of cessation aids; perceived medication side effects; and conflation of the harms resulting from use of tobacco products and nicotine replacement therapy. Innovative and effective interventions must account for the aforementioned multiple barriers to cessation as well as prior experiences with and misperceptions regarding cessation aids.

Machine learning prediction of neurocognitive impairment among people with HIV using clinical and multimodal magnetic resonance imaging data

Diagnosis of HIV-associated neurocognitive impairment (NCI) continues to be a clinical challenge. The purpose of this study was to develop a prediction model for NCI among people with HIV using clinical- and magnetic resonance imaging (MRI)-derived features. The sample included 101 adults with chronic HIV disease. NCI was determined using a standardized neuropsychological testing battery comprised of seven domains. MRI features included gray matter volume from high-resolution anatomical scans and white matter integrity from diffusion-weighted imaging. Clinical features included demographics, substance use, and routine laboratory tests. Least Absolute Shrinkage and Selection Operator Logistic regression was used to perform variable selection on MRI features. These features were subsequently used to train a support vector machine (SVM) to predict NCI. Three different classification tasks were performed: one used only clinical features; a second used only selected MRI features; a third used both clinical and selected MRI features. Model performance was evaluated by area under the receiver operating characteristic curve (AUC), accuracy, sensitivity, and specificity with a tenfold cross-validation. The SVM classifier that combined selected MRI with clinical features outperformed the model using clinical features or MRI features alone (AUC: 0.83 vs. 0.62 vs. 0.79; accuracy: 0.80 vs. 0.65 vs. 0.72; sensitivity: 0.86 vs. 0.85 vs. 0.86; specificity: 0.71 vs. 0.37 vs. 0.52). Our results provide preliminary evidence that combining clinical and MRI features can increase accuracy in predicting NCI and could be developed as a potential tool for NCI diagnosis in HIV clinical practice.

Synergistic effects of HIV and marijuana use on functional brain network organization

HIV is associated with disruptions in cognition and brain function. Marijuana use is highly prevalent in HIV but its effects on resting brain function in HIV are unknown. Brain function can be characterized by brain activity that is correlated between regions over time, called functional connectivity. Neuropsychiatric disorders are increasingly being characterized by disruptions in such connectivity. We examined the synergistic effects of HIV and marijuana use on functional whole-brain network organization during resting state. Our sample included 78 adults who differed on HIV and marijuana status (19 with co-occurring HIV and marijuana use, 20 HIV-only, 17 marijuana-only, and 22 controls). We examined differences in local and long-range brain network organization using eight graph theoretical metrics: transitivity, local efficiency, within-module degree, modularity, global efficiency, strength, betweenness, and participation coefficient. Local and long-range connectivity were similar between the co-occurring HIV and marijuana use and control groups. In contrast, the HIV-only and marijuana-only groups were both associated with disruptions in brain network organization. These results suggest that marijuana use in HIV may normalize disruptions in brain network organization observed in persons with HIV. However, future work is needed to determine whether this normalization is suggestive of a beneficial or detrimental effect of marijuana on cognitive functioning in HIV.

Reciprocal Influences of HIV and Cannabinoids on the Brain and Cognitive Function

Globally, cannabis is the most commonly used illicit drug, with disproportionately high use among persons with HIV. Despite advances in HIV care, nearly half of persons living with HIV continue to experience neurocognitive deficits or impairments that may have negative impacts on their daily function. Chronic cannabis use may play a role in the development or exacerbation of these impairments. Here we present a review summarizing existing research detailing the effect of cannabis use associated with the neuropathogenesis of HIV. We examine evidence for possible additive or synergistic effects of HIV infection and cannabis use on neuroHIV in both the preclinical and adult human literatures, including in vitro studies, animal models, clinical neuroimaging research, and studies examining the cognitive effects of cannabis. We discuss the limitations of existing research, including methodological challenges involved with clinical research with human subjects. We identify gaps in the field and propose critical research questions to advance our understanding of how cannabis use affects neuroHIV. Graphical Abstract.

Cognitive Impairment among People Who Use Heroin and Fentanyl: Findings from the Miami Adult Studies on HIV (MASH) Cohort

Background: Cognitive impairment is common in people living with HIV (PLWH). Opioid drugs exert direct and indirect effects on cognitive processes, which may contribute to cognitive dysfunction among PLWH. This study was designed to determine if opioid use is associated with cognitive impairment and whether the effect differs between PLWH and HIV-uninfected adults. Other neuropsychiatric symptoms, such as depression and apathy, were also examined. We conducted a cross-sectional analysis of 265 PLWH and 284 HIV-uninfected participants from the Miami Adult Studies on HIV (MASH) cohort. The Mini-Mental State Examination (MMSE) was used to assess cognitive impairment. Substance use was self-reported. Overall, 26.8% of PLWH and 15.1% of HIV-uninfected used opioids. Cognitive impairment was more frequent among people who used heroin and/or fentanyl than those who misused prescription opioids (31.6% vs. 10.5%, p = .005). The use of heroin/fentanyl was associated with increased odds for cognitive impairment (adjusted OR: 2.21, 95% CI 1.05-4.64, p = .036). Among PLWH only, the misuse of opioids was associated with a higher frequency of neuropsychiatric symptoms such as depression and apathy. A higher risk for cognitive impairment was seen among people who used heroin and fentanyl. PLWH who misuse opioids may be at an increased risk for neuropathology, but elucidation of mechanisms for opioid-induced cognitive deficits is needed.

Tryptophan degradation is associated with risk-taking propensity in methamphetamine users with treated HIV infection

Few studies have examined neuroimmune pathways that could contribute to impulsivity in people living with HIV who use substances. Eighty-four methamphetamine-using, sexual minority men with an undetectable HIV viral load were administered the Balloon Analogue Risk Task (BART), a behavioral measure of risk-taking propensity. We examined the associations between kynurenine/tryptophan ratio and phenylalanine/tyrosine ratio with BART scores using multiple linear regression. A higher kynurenine/tryptophan ratio was independently associated with greater BART scores (beta = 0.25; 95% CI = 0.05-1.23; p = 0.034). The phenylalanine/tyrosine ratio was not significantly associated with BART scores. Findings support the need for further research to elucidate the neuroimmune mechanisms linking tryptophan degradation with impulsivity to catalyze the development novel pharmacologic treatments for people living with HIV who use methamphetamine.

Neural sensitivity to risk in adults with co-occurring HIV infection and cocaine use disorder

Persons with co-occurring HIV infection and cocaine use disorder tend to engage in riskier decision-making. However, the neural correlates of sensitivity to risk are not well-characterized in this population. The purpose of this study was to examine the neural interaction effects of HIV infection and cocaine use disorder to sensitivity to risk. The sample included 79 adults who differed on HIV status and cocaine use disorder. During functional magnetic resonance imaging (fMRI), participants completed a Wheel of Fortune (WoF) task that assessed neural activation in response to variations of monetary risk (i.e., lower probability of winning a larger reward). Across groups, neural activation to increasing risk was in cortical and subcortical regions similar to previous investigations using the WoF in nondrug-using populations. Our analyses showed that there was a synergistic effect between HIV infection and cocaine use in the left precuneus/posterior cingulate cortex and hippocampus, and right postcentral gyrus, lateral occipital cortex, cerebellum, and posterior parietal cortex. HIV+ individuals with cocaine use disorder displayed neural hyperactivation to increasing risk that was not observed in the other groups. These results support a synergistic effect of co-occurring HIV infection and cocaine dependence in neural processing of risk probability that may reflect compensation. Future studies can further investigate and validate how neural activation to increasing risk is associated with risk-taking behavior.

HIV Prevalence and Associated Risks in a Respondent-Driven Sample of Illicit Stimulant Users in a Southern United States City

Stimulant abuse is a major contributor to HIV transmission in the United States, yet HIV prevalence among persons who use illicit stimulants remains unknown. We implemented respondent driven sampling (RDS) to estimate the prevalence of HIV infection in this high-risk population. We also examined RDS-adjusted rates of risk behaviors among HIV-positive and HIV-negative participants. Recruited from seven seeds, our sample of 387 participants was 46% female, 89% African American, and 45.94 years old on average. Participants were predominantly non-injection cocaine users, had large networks of stimulant users, and reported an established relationship with their recruiter. The adjusted population proportion of HIV infection was 0.07 (0.04, 0.11). The majority of sexually active participants reported engagement in risk behaviors (73%), but rates generally did not differ by HIV status. Our results highlight that stimulant use is a risk factor for HIV infection. This study also demonstrates that RDS is a very effective strategy for reaching stimulant users in the community.

Cocaine-related alterations in fronto-parietal gray matter volume correlate with trait and behavioral impulsivity

BACKGROUND

Chronic cocaine use is associated with structural brain abnormalities within prefrontal regions implicated in impulsivity. Despite high levels of impulsivity among persons who use cocaine, it is not known how reductions in gray matter volume (GMV) may relate to trait and behavioral measures of impulsivity.

METHODS

The sample included 39 active cocaine users (COC+) and 40 controls with no history of cocaine use (COC-). Participants had a brain scan on a 3 T MRI machine and completed out-of-scanner measures of trait impulsivity and delayed reward discounting. Whole-brain voxel-based morphometry was used to compare GMV between COC+ and COC-. Within regions that differed between groups, voxelwise correlations were conducted to examine the relationship between GMV and impulsivity.

RESULTS

In a whole-brain analysis, COC+ had broad reductions in GMV compared to COC- in bilateral frontal, parietal, occipital, and cerebellar regions. Lower GMV correlated with trait impulsivity in lateral prefrontal regions and with delayed reward discounting in medial prefrontal regions, while lower GMV correlated with both measures in the posterior parietal cortex. COC+ demonstrated significantly higher impulsivity than COC- on all measures, but the nature of the correlation with GMV was similar in both groups.

CONCLUSIONS

Reflecting the multi-faceted nature of impulsivity, these results show that trait and behavioral measures of impulsivity map differentially onto altered brain morphology. While the brain-behavior patterns were similar in COC+ and COC-, suggesting that impulsivity varies on a continuous spectrum, cocaine-related abnormalities in frontal-parietal brain systems may contribute to heightened impulsivity.

Problematic alcohol use among fathers in Kenya: Poverty, people, and practices as barriers and facilitators to help acceptance

BACKGROUND

In Kenya, the prevalence of alcohol use disorder (AUD) is close to 6%, but a notable treatment gap persists. AUD is especially pronounced among men, leading to negative consequences at both individual and family levels. This study examines the experiences of problem-drinking fathers in Kenya regarding previous treatment-seeking related to alcohol use. Experiences and dynamics of the family are also explored as they pertain to treatment-seeking experiences.

METHODS

In Eldoret, Kenya, semi-structured qualitative interviews were conducted with 11 families with a male exhibiting problem drinking, his spouse, and one child. Thematic content analysis was used to examine themes related to barriers and facilitators to treatment.

RESULTS

Participants only reported informal help received from family and community members; they exhibited little awareness of available formal treatments. Families were both deeply affected by alcohol use and actively involved in help-seeking. Indeed, fathers' experiences are described as help-accepting rather than help-seeking. Three overarching themes emerged from the results: poverty, people, and practices. Poverty could be a motivator to accept help to support one's family financially, but stress from lack of work also drove drinking behaviours. People were also crucial as both barriers and facilitators of help-accepting. Negative help strategies or peer influence deterred fathers from accepting help to quit. Positive motivation, social support, and stigma against drinking were motivators. Practices that were culturally salient, such as religiosity and gender roles, facilitated help acceptance. Overall, most help efforts were short-term and only lead to very short-term behaviour change.

CONCLUSION

Families and communities are active in help provision for problem-drinking men in Kenya, though results confirm remaining need for effective interventions. Future interventions could benefit from recognizing the role of family to aid in treatment-engagement and attending to the importance of poverty, people, and practices in designing treatment strategies.

Synergistic effects of marijuana abuse and HIV infection on neural activation during a cognitive interference task

Marijuana use, which is disproportionately prevalent among human immunodeficiency virus (HIV)-infected persons, can alter activity in fronto-parietal regions during cognitively demanding tasks. While HIV is also associated with altered neural activation, it is not known how marijuana may further affect brain function in this population. Our study examined the independent and additive effects of HIV infection and regular marijuana use on neural activation during a cognitive interference task. The sample included 93 adults who differed on marijuana (MJ) and HIV statuses (20 MJ+/HIV+, 19 MJ+/HIV-, 29 MJ-/HIV+, 25 MJ-/HIV-). Participants completed a counting Stroop task during a functional magnetic resonance imaging scan. Main and interactive effects on neural activation during interference versus neutral blocks were examined using a mixed-effects analysis. The sample showed the expected Stroop effect for both speed and accuracy. There were main effects of MJ in the right and left inferior parietal lobules, with the left cluster extending into the posterior middle temporal gyrus and a main effect of HIV in the dorsal anterior cingulate cortex. There was an interaction in the left fronto-insular cortex, such that the MJ+/HIV+ group had the largest increase in activation compared with other groups. Among MJ+, signal change in this cluster correlated positively with cumulative years of regular marijuana use. These results suggest that comorbid HIV and marijuana use is associated with complex neural alterations in multiple brain regions during cognitive interference. Follow-up research is needed to determine how marijuana-related characteristics may moderate HIV neurologic disease and impact real-world functioning.

Sexual Orientation, Religious Coping, and Drug Use in a Sample of HIV-Infected African-American Men Living in the Southern USA

Religiosity and spirituality are associated with reduced drug use in the general population, but it is unclear whether this relationship generalizes to sexual minorities. This study investigated the relationship between religious coping, drug use, and sexual orientation in a sample of HIV-infected African-American men (40 heterosexuals; 64 sexual minorities). Most participants (76%) reported being "moderately" or "very" religious. We found no main effect of religious coping or sexual orientation on frequency of drug use. However, there was an interaction between positive religious coping and sexual orientation. Among heterosexuals, positive religious coping was inversely associated with frequency of drug use. However, this relationship was not significant among sexual minorities. Findings suggest HIV-infected African-American sexual minorities living in the South may need additional coping resources to decrease vulnerability to drug use.

Reward and executive control network resting-state functional connectivity is associated with impulsivity during reward-based decision making for cocaine users

BACKGROUND

Cocaine addiction is related to impulsive decision making that is mediated by brain circuitry involved in reward processing and executive functions, such as cognitive control and attentional salience. Resting-state functional connectivity between reward and executive control circuitry is altered among cocaine users, with concomitant deficits in impulsivity and learning. Prior research has examined how select brain regions interact to influence impulsive decision making for drug users; however, research examining interactions between large-scale brain networks and impulsive behavior is limited.

METHODS

The current study compared reward and executive control network resting-state functional connectivity and its relationship to impulsive decision making between cocaine users (n = 37) and non-cocaine using control participants (n = 35). Participants completed computerized decision-making tasks and a separate resting-state functional magnetic resonance imaging scan. Data underwent independent component, dual regression, and linear regression moderation analyses.

RESULTS

Higher impulsivity on the Balloon Analogue Risk Task (BART) was associated with inverse resting-state connectivity between the left cognitive control and subgenual anterior cingulate extended reward networks for cocaine users, while the opposite was found for controls. Less impulsivity on the monetary choice questionnaire was associated with stronger positive resting-state connectivity between the attentional salience and striatal core reward networks for controls, while cocaine users showed no association between impulsivity and resting-state connectivity of these networks.

CONCLUSIONS

Cocaine users show aberrant associations between reward-executive control resting-state network coupling and impulsive decision making. The findings support the conclusion that an imbalance between reward and executive control circuitry contributes to impulsivity in drug use.

A Comparison of Motivations for Marijuana Use in HIV-Positive and HIV-Negative Adults

While medicinal marijuana use is common among persons with HIV, it is not known whether persons with HIV are more motivated to use marijuana medically compared to HIV-negative counterparts. This study examined motivations for marijuana use in a sample of 94 HIV+ and HIV- adults. Participants used marijuana 21.27 days in the last 30 days on average. HIV+ participants reported using marijuana for medical reasons more often than HIV- participants, but HIV+ and HIV- participants did not differ in other domains. Problematic marijuana use was associated with motives, regardless of HIV status. Motives were associated with mental and physical health functioning, but there were no interactions between motivations and HIV status. Overall this study found that motivations were similar for HIV+ and HIV- participants. Future research including qualitative work to further understand motivations would benefit the field, as would research examining the effectiveness of marijuana in treating physical symptoms.

Facilitators and Barriers to Naloxone Kit Use Among Opioid-Dependent Patients Enrolled in Medication Assisted Therapy Clinics in North Carolina

BACKGROUND Naloxone-an opioid antagonist that reverses the effects of opioids-is increasingly being distributed in non-medical settings. We sought to identify the facilitators of, and barriers to, opioid users using naloxone kits in North Carolina.METHODS In 2015, we administered a 15-item survey to a convenience sample of 100 treatment seekers at 4 methadone/buprenorphine Medication Assisted Therapy (MAT) clinics in North Carolina.RESULTS Seventy-four percent of participants reported having ever gotten a naloxone kit; this percentage was higher for females (81%) than males (63%) (P = .06). The primary reason given for not having a kit was not knowing where to get one. Only 6% had heard of kits from the media and only 5% received one from a medical provider. Among kit recipients, 56% of both females and males reported mostly or sometimes carrying the kit, with additional participants reporting always. Reasons for not carrying a kit were no longer being around drugs, forgetting it, and the kit being too large. Men discussed the difficulties of carrying the naloxone kits, which are currently too large to fit in a pocket. Ninety-four percent of naloxone users reported intending to call emergency services in case of an overdose emergency.LIMITATIONS Study limitations included a small sample, participants limited to MAT clinics, and a predominantly white sample.CONCLUSIONS MAT treatment seekers reported a willingness to carry and use naloxone kits. Education, outreach, media, and medical providers need to promote naloxone kits. A smaller kit may increase the likelihood of men carrying one.

The Impact of Marijuana Use on Memory in HIV-Infected Patients: A Comprehensive Review of the HIV and Marijuana Literatures

BACKGROUND

The most robust neurocognitive effect of marijuana use is memory impairment. Memory deficits are also high among persons living with HIV/AIDS, and marijuana is the most commonly used drug in this population. Yet research examining neurocognitive outcomes resulting from co-occurring marijuana and HIV is limited.

OBJECTIVE

The primary objectives of this comprehensive review are to: (1) examine the literature on memory functioning in HIV-infected individuals; (2) examine the literature on memory functioning in marijuana users; (3) synthesize findings and propose a theoretical framework to guide future research.

METHOD

PubMed was searched for English publications 2000-2013. Twenty-two studies met inclusion criteria in the HIV literature, and 23 studies in the marijuana literature.

RESULTS

Among HIV-infected individuals, memory deficits with medium to large effect sizes were observed. Marijuana users also demonstrated memory problems, but results were less consistent due to the diversity of samples.

CONCLUSION

A compensatory hypothesis, based on the cognitive aging literature, is proposed to provide a framework to explore the interaction between marijuana and HIV. There is some evidence that individuals infected with HIV recruit additional brain regions during memory tasks to compensate for HIV-related declines in neurocognitive functioning. Marijuana is associated with disturbance in similar brain systems, and thus it is hypothesized that the added neural strain of marijuana can exhaust neural resources, resulting in pronounced memory impairment. It will be important to test this hypothesis empirically, and future research priorities are discussed.

Cocaine and HIV are independently associated with neural activation in response to gain and loss valuation during economic risky choice

Stimulant abuse is disproportionately common in HIV-positive persons. Both HIV and stimulants are independently associated with deficits in reward-based decision making, but their interactive and/or additive effects are poorly understood despite their prevalent co-morbidity. Here, we examined the effects of cocaine dependence and HIV infection in 69 adults who underwent functional magnetic resonance imaging while completing an economic loss aversion task. We identified two neural networks that correlated with the evaluation of the favorable characteristics of the gamble (i.e. higher gains/lower losses: ventromedial prefrontal cortex, anterior cingulate, anterior and posterior precuneus and visual cortex) versus unfavorable characteristics of the gamble (i.e. lower gains/higher losses: dorsal prefrontal, lateral orbitofrontal, posterior parietal cortex, anterior insula and dorsal caudate). Behaviorally, cocaine and HIV had additive effects on loss aversion scores, with HIV-positive cocaine users being the least loss averse. Cocaine users had greater activation in brain regions that tracked the favorability of gamble characteristics (i.e. increased activation to gains, but decreased activation to losses). In contrast, HIV infection was independently associated with lesser activation in regions that tracked the unfavorability of gamble characteristics. These results suggest that cocaine is associated with an overactive reward-seeking system, while HIV is associated with an underactive cognitive control system. Together, these alterations may leave HIV-positive cocaine users particularly vulnerable to making unfavorable decisions when outcomes are uncertain.

Gender and Sex Trading Among Active Methamphetamine Users in Cape Town, South Africa

BACKGROUND

South Africa has experienced a tremendous rise in methamphetamine use since the year 2000. Sex trading is a global phenomenon that has been observed in active drug users and has been associated with risks for HIV infection and violence.

OBJECTIVES

This paper describes and examines the correlates of sex trading among active methamphetamine users in Cape Town, South Africa.

METHODS

Through peer referral, 360 (201 male; 159 female) active methamphetamine users were recruited in a peri-urban township. Demographics, sex trading, drug use, trauma, and mental health were assessed by a structured clinical interview and computer survey. Logistic regression models were used to examine predictors of sex trading for men and women.

RESULTS

In the past 3 months, 40% of men and 33% of women endorsed trading sex for methamphetamine or money. Among these, they reported trading with same sex partners (33%), high rates of inconsistent condom use (73%), and incidences of physical (23%) and sexual (27%) assault when sex trading. Increased drug use severity was correlated with sex trading. Women with experiences of violence and trauma were also more likely to trade sex. Conclusions/importance: The results stress a need for linkage to drug treatment, as addiction may be fueling sex trading. Targeted interventions geared towards safe sex practices may reduce risky sexual behaviors. Women need interventions that are attuned to their specific vulnerabilities. More research is needed to explore the experiences of men who have sex with men given their particularly high rates of sex trading behavior.

The Acceptability and Potential Utility of Cognitive Training to Improve Working Memory in Persons Living With HIV: A Preliminary Randomized Trial

HIV-associated neurocognitive impairments that impact daily function persist in the era of effective antiretroviral therapy. Cognitive training, a promising low-cost intervention, has been shown to improve neurocognitive functioning in some clinical populations. We tested the feasibility, acceptability, and preliminary effects of computerized cognitive training to improve working memory in persons living with HIV infection (PLWH) and working memory impairment. In this randomized clinical trial, we assigned 21 adult PLWH to either an experimental cognitive training intervention or an attention-matched control training intervention. Participants completed 12 training sessions across 10 weeks with assessments at baseline and post-training. Session attendance was excellent and participants rated the program positively. Participants in the experimental arm demonstrated improved working memory function over time; participants in the control arm showed no change. Our results suggest that cognitive training may be a promising intervention for working memory impairment in PLWH and should be evaluated further.

Food Insecurity Is Associated with Cognitive Deficits Among HIV-Positive, But Not HIV-Negative, Individuals in a United States Sample

People living with HIV/AIDS (PLWHA) in the United States (US) have disproportionately high rates of food insecurity (FI). In the general population, FI has been associated with cognitive impairment among older adults and may exacerbate HIV-associated neurocognitive disorders. The current study assessed the effects of FI and HIV infection on the neuropsychological performance of 61 HIV-positive and 36 HIV-negative adults in the US. While the main effects were minimal, the interactive effects revealed that FI was related to deficits in speed of information processing, learning, memory, motor function, and overall cognitive impairment for the HIV-positive group, but not the HIV-negative group. The interactive effects remained after controlling for relevant sociodemographic characteristics. Although bidirectional associations cannot be ruled out in a cross-sectional study, the results suggest that FI may contribute to cognitive impairment among HIV-positive adults in the US. Given the high rates of socioeconomic disadvantage among PLWHA in the US, addressing FI as part of routine clinical care may be warranted.

Heterosexual Anal Sex Among Men and Women in Substance Abuse Treatment: Secondary Analysis of Two Gender-Specific HIV-Prevention Trials

Receptive anal sex has high human immunodeficiency virus (HIV) transmission risk, and heterosexual substance-abusing individuals report higher anal sex rates compared to their counterparts in the general population. This secondary analysis evaluated the effectiveness of two gender-specific, evidence-based HIV-prevention interventions (Real Men Are Safe, or REMAS, for men; Safer Sex Skill Building, or SSSB, for women) against an HIV education (HIV-Ed) control condition on decreasing unprotected heterosexual anal sex (HAS) among substance abuse treatment-seeking men (n = 171) and women (n = 105). Two variables, engagement in any HAS and engagement in unprotected HAS, were assessed at baseline and three months postintervention. Compared to the control group, women in the gender-specific intervention did not differ on rates of any HAS at follow-up but significantly decreased their rates of unprotected HAS. Men in both the gender-specific and the control interventions reported less HAS and unprotected HAS at three-month follow-up compared to baseline, with no treatment condition effect. The mechanism of action for SSSB compared to REMAS in decreasing unprotected HAS is unclear. More attention to HAS in HIV-prevention interventions for heterosexual men and women in substance abuse treatment is warranted.

The role of substance use coping in the relation between childhood sexual abuse and depression among methamphetamine users in South Africa

OBJECTIVE

Childhood sexual abuse (CSA) is a critical global health issue associated with poor psychosocial outcomes. Individuals with CSA histories are at risk for drug use, which is a growing problem in the Western Cape of South Africa. The present study of methamphetamine users in this region examined whether substance use coping, a contextually relevant type of avoidance-based coping, mediates the relation between CSA and depressive symptoms.

METHOD

Participants included 161 men and 108 women seeking treatment for methamphetamine use. Participants completed a computer-assisted survey and a face-to-face interview with clinic staff to evaluate history of CSA, current substance use severity and coping, and current depressive symptoms.

RESULTS

Nearly a third of participants reported a history of CSA, and the average methamphetamine use severity score exceeded the threshold of high risk. A history of CSA was significantly associated with higher substance use coping and more depression symptoms. Substance use coping was a significant mediator of the association between CSA and depression symptoms.

CONCLUSIONS

In this study of high-risk methamphetamine users, substance use coping emerged as a common means of managing stress, especially for those with a history of CSA, which was further linked to depressive symptoms. These findings underscore the potential benefit of integrating coping interventions and mental health treatment into substance abuse treatment programs, particularly for those with a history of childhood abuse and violence. (PsycINFO Database Record

HIV testing and sero-prevalence among methamphetamine users seeking substance abuse treatment in Cape Town

INTRODUCTION AND AIMS

Methamphetamine use is highly prevalent in parts of South Africa, and there is concern this will contribute to the country's substantial HIV epidemic. We examined the feasibility of implementing routine HIV testing at a community-based substance abuse treatment centre in Cape Town and determined the HIV sero-prevalence among methamphetamine users seeking treatment at this site.

DESIGN AND METHODS

In this cross-sectional study, 293 participants completed measures of demographics, substance use and HIV treatment. HIV sero-prevalence was determined by a rapid finger-prick HIV test, and prior HIV diagnosis was confirmed via clinic records.

RESULTS

The majority of participants were male and self-identified as 'Coloured', with a mean age of 28 years. The HIV sero-prevalence was 3.8%. Of the 11 participants who tested HIV positive, four were newly diagnosed. HIV-positive and HIV-negative participants were comparable on demographic and substance use factors. Uptake of HIV testing among all clients at the drug treatment centre increased from <5% prior to study initiation to 89% after study completion. Measures implemented to ensure high rates of HIV testing were regarded as sustainable.

DISCUSSION AND CONCLUSIONS

Our study suggests that integrating routine HIV testing into substance abuse treatment is feasible in a community-based health centre. The low HIV prevalence among this sample of treatment-seeking methamphetamine users highlights the potential benefits of supporting expanded efforts to optimise HIV prevention with this young adult population. [Gouse H, Joska JA, Lion RR, Watt MH, Burnhams W, Carrico AW, Meade CS. HIV testing and sero-prevalence among methamphetamine users seeking substance abuse treatment in Cape Town. Drug Alcohol Rev 2016;35:580-583].

Intimate partner violence among men and women who use methamphetamine: A mixed-methods study in South Africa

INTRODUCTION

The prevalence of methamphetamine use has risen dramatically in parts of South Africa. Globally, methamphetamine has been linked to intimate partner violence (IPV) and other forms of aggression. The aim of this mixed-methods study was to examine the experiences of physical IPV and its contextual factors among methamphetamine users in an urban community in Cape Town, South Africa.

METHODS

Active methamphetamine users were recruited using respondent driven sampling. All participants (n = 360) completed structured surveys, and a subset (n = 30) completed in-depth interviews with discussions of personal IPV experiences. Quantitative data were examined separately by gender, and regression models were used to identify factors that were associated with physical IPV victimisation and perpetration. Qualitative data were analysed to provide contextual understanding.

RESULTS

In the past 3 months, 47% of women and 31% of men reported being a victim of IPV, and 30% of women and 28% men reported being a perpetrator of IPV. Victimisation and perpetration were highly correlated, and both were significantly associated with histories of other traumas. Although the survey data suggests gender equivalence in IPV, the qualitative data provides a more nuanced context, with female victimisation by male partners being particularly frequent and intense. In narratives, IPV was a product of male aggression while using methamphetamine, norms around sex trading and gender-based attitudes endorsing violence against women.

CONCLUSION

Addiction to methamphetamine creates heightened risks of IPV, especially among those with previous traumas. The findings emphasise the importance of identifying and addressing IPV among methamphetamine users in South Africa. [Watt MH, Guidera KE, Hobkirk AL, Skinner D, Meade CS. Intimate partner violence among men and women who use methamphetamine: A mixed-methods study in South Africa. Drug Alcohol Rev 2017;36:97-106].