The mental health experiences and needs of methamphetamine users in Cape Town: A mixed-methods study

Background. South Africa (SA) has a burgeoning problem of methamphetamine use, particularly in the Western Cape Province. Although methamphetamine has been associated with elevated psychological distress, there has been little examination of the mental health needs of out-of-treatment methamphetamine users in SA.Objective. To describe the mental health experiences and needs of out-of-treatment methamphetamine users in Cape Town. Methods. Active methamphetamine users were recruited using respondent-driven sampling techniques. Eligible participants (N=360) completed a computer-assisted assessment and clinical interview, where they provided data on mental health symptoms and treatment- seeking behaviour. A subset of 30 participants completed qualitative in-depth interviews in which they provided narrative accounts of their mental health experiences and needs. Analysis of the mixed-methods data was conducted using a concurrent triangulation strategy whereby both methods contributed equally to the analysis and were used for cross-validation. Results. About half of the participants met screening criteria for depression and traumatic stress, and there were some indications of paranoia. Using substances to cope with psychological distress was common, with participants talking about using methamphetamine to numb their feelings or forget stressful memories. One-third of women and 13% of men had previously tried to commit suicide. Despite the huge mental health burden in this population, very few had ever received mental health treatment. Conclusion. The data indicate a need for integrated care that addresses both substance use and psychiatric needs in this population. Mental health and drug treatment services targeting methamphetamine users should include a concerted focus on suicide prevention.

Independent effects of HIV infection and cocaine dependence on neurocognitive impairment in a community sample living in the southern United States

Prior studies have established that methamphetamine and HIV can have additive deleterious effects on neurocognitive functioning, but there has been relatively little research on other stimulants like cocaine. This study investigated the effects of cocaine and HIV on neurocognitive impairment in a large, well-characterized sample

Cocaine Use Prediction with Tensor-based Machine Learning on Multimodal MRI Connectome Data

This paper considers the use of machine learning algorithms for predicting cocaine use based on magnetic resonance imaging (MRI) connectomic data. The study utilized 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 datasets 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) $\times 2$ (fMRI and dMRI) $\times 246$ (ROIs) $\times 246$ (ROIs) to $275$ (individuals) $\times 2$ (fMRI and dMRI) $\times 6$ (clusters) $\times 6$ (clusters). This was achieved by applying the high-order Lloyd algorithm to group the ROI data into 6 clusters. Features were extracted from the reduced tensor and combined with demographic features (age, gender, race, and HIV status). The resulting dataset 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

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

Integration of new biological and physical retrospective dosimetry methods into EU emergency response plans : joint RENEB and EURADOS inter-laboratory comparisons

Purpose: RENEB, 'Realising the European Network of Biodosimetry and Physical Retrospective Dosimetry,' is a network for research and emergency response mutual assistance in biodosimetry within the EU. Within this extremely active network, a number of new dosimetry methods have recently been proposed or developed. There is a requirement to test and/or validate these candidate techniques and inter-comparison exercises are a well-established method for such validation. Materials and methods: The authors present details of inter-comparisons of four such new methods: dicentric chromosome analysis including telomere and centromere staining; the gene expression assay carried out in whole blood; Raman spectroscopy on blood lymphocytes, and detection of radiation induced thermoluminescent signals in glass screens taken from mobile phones. Results: In general the results show good agreement between the laboratories and methods within the expected levels of uncertainty, and thus demonstrate that there is a lot of potential for each of the candidate techniques. Conclusions: Further work is required before the new methods can be included within the suite of reliable dosimetry methods for use by RENEB partners and others in routine and emergency response scenarios

Phenome-wide association analysis of LDL-cholesterol lowering genetic variants in PCSK9

Abstract: Background: We characterised the phenotypic consequence of genetic variation at the PCSK9 locus and compared findings with recent trials of pharmacological inhibitors of PCSK9. Methods: Published and individual participant level data (300,000+ participants) were combined to construct a weighted PCSK9 gene-centric score (GS). Seventeen randomized placebo controlled PCSK9 inhibitor trials were included, providing data on 79,578 participants. Results were scaled to a one mmol/L lower LDL-C concentration. Results: The PCSK9 GS (comprising 4 SNPs) associations with plasma lipid and apolipoprotein levels were consistent in direction with treatment effects. The GS odds ratio (OR) for myocardial infarction (MI) was 0.53 (95% CI 0.42; 0.68), compared to a PCSK9 inhibitor effect of 0.90 (95% CI 0.86; 0.93). For ischemic stroke ORs were 0.84 (95% CI 0.57; 1.22) for the GS, compared to 0.85 (95% CI 0.78; 0.93) in the drug trials. ORs with type 2 diabetes mellitus (T2DM) were 1.29 (95% CI 1.11; 1.50) for the GS, as compared to 1.00 (95% CI 0.96; 1.04) for incident T2DM in PCSK9 inhibitor trials. No genetic associations were observed for cancer, heart failure, atrial fibrillation, chronic obstructive pulmonary disease, or Alzheimer’s disease – outcomes for which large-scale trial data were unavailable. Conclusions: Genetic variation at the PCSK9 locus recapitulates the effects of therapeutic inhibition of PCSK9 on major blood lipid fractions and MI. While indicating an increased risk of T2DM, no other possible safety concerns were shown; although precision was moderate

Neurocognitive impairment and medication adherence in HIV patients with and without cocaine dependence

Cocaine abuse among HIV patients is associated with faster disease progression and mortality. This study examined the relationship between neurocognitive functioning and medication adherence in HIV patients with (n = 25) and without (n = 39) current cocaine dependence. Active users had greater neurocognitive impairment (mean T-score = 35.16 vs. 40.97, p < .05) and worse medication adherence (mean z-score = -0.44 vs. 0.27, p < .001). In a multiple regression model, neurocognitive functioning (β = .33, p < .01) and cocaine dependence (β = -.36, p < .01) were predictive of poorer adherence. There was a significant indirect effect of cocaine dependence on medication adherence through neurocognitive impairment (estimate = -0.15, p < .05), suggesting that neurocognitive impairment partially mediated the relationship between cocaine dependence and poorer adherence. These results confirm that cocaine users are at high risk for poor HIV outcomes and underscore the importance of treating both neurocognitive impairment and cocaine dependence among HIV patients

Coping Styles and Illicit Drug Use in Older Adults With HIV/AIDS

The prevalence of HIV infection in older adults is increasing; by 2015, over half of adults living with HIV/AIDS in the United States will be over 50. This study describes the prevalence of drug use and examines psychosocial predictors of drug use in a sample of HIV-infected adults aged 50 and older. Participants were 301 HIV-positive older adults enrolled in a clinical trial of a coping intervention aimed to reduce their depressive symptoms. One-quarter used illicit drugs in the past 60 days (48% any cocaine, 48% weekly marijuana, 44% any other drugs) with an average of 36 days for marijuana and 15 days for cocaine. After controlling for demographics, self-destructive avoidance was positively associated and spiritual coping was negatively associated with drug use. These findings suggest that assessment of drug abuse should be a routine part of care for older patients in HIV clinics. Furthermore, interventions designed to increase spiritual coping and decrease self-destructive avoidance may be particularly efficacious for HIV-infected older adults