Lifetime marijuana and alcohol use, and cognitive dysfunction in people with human immunodeficiency virus infection

Moderate-to-severe cognitive impairment is associated with both recent and chronic alcohol misuse in people with HIV: The New Orleans alcohol use in HIV (NOAH) study

BACKGROUND

Human immunodeficiency virus (HIV) profoundly impacts the nervous system, leading to neurological deficits including HIV-associated neurocognitive disorder (HAND). HAND represents the most common neurological comorbidity among people with HIV (PWH), and alcohol use may exacerbate cognitive deficits, especially in vulnerable populations. This study investigated relationships between alcohol use and cognition in an underserved cohort of PWH, on the hypothesis that alcohol misuse exacerbates cognitive deficits.

METHODS

Data collected from participants (n = 259; 66.7% male; mean age 52 ± 10 years) enrolled in the New Orleans Alcohol Use in HIV (NOAH) study were utilized for cross-sectional analysis. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA), and alcohol use was comprehensively measured using four metrics: the Alcohol Use Disorders Identification Test (AUDIT), 30-day timeline follow back (TLFB), lifetime drinking history, and phosphatidylethanol (PEth) levels.

RESULTS

The average MoCA score among participants was 20.7 ± 4.5, with 86.5% demonstrating cognitive impairment (MoCA < 26). Individuals with MoCA scores below 18 (moderately or severely cognitively impaired) had a higher frequency of recent severe alcohol misuse and greater lifetime alcohol consumption. Participants at increased risk for AUD (AUDIT ≥ 16) also had worse global cognition and memory task performance than those with lower AUDIT scores; this was particularly true among those aged 50 and older. Analysis of the MoCA sub-score data indicated that participants with increased AUD risk had impairments in the cognitive domains of language and memory.

CONCLUSIONS

Our findings demonstrate a high prevalence of cognitive impairment in the NOAH cohort and suggest that alcohol misuse contributes to global cognitive deficits in PWH, especially among individuals aged 50 and older. Further exploration of the impact of alcohol use on specific cognitive domains, including memory and language, should incorporate additional cognitive tasks. These findings highlight the importance of considering alcohol use and AUD risk as significant factors that may exacerbate cognitive deficits in vulnerable populations, including older PWH.

The Impact of Cannabis Use on Cognition in People with HIV: Evidence of Function-Dependent Effects and Mechanisms from Clinical and Preclinical Studies

PURPOSE OF REVIEW

Cannabis may have beneficial anti-inflammatory effects in people with HIV (PWH); however, given this population's high burden of persisting neurocognitive impairment (NCI), clinicians are concerned they may be particularly vulnerable to the deleterious effects of cannabis on cognition. Here, we present a systematic scoping review of clinical and preclinical studies evaluating the effects of cannabinoid exposure on cognition in HIV.

RECENT FINDINGS

Results revealed little evidence to support a harmful impact of cannabis use on cognition in HIV, with few eligible preclinical data existing. Furthermore, the beneficial/harmful effects of cannabis use observed on cognition were function-dependent and confounded by several factors (e.g., age, frequency of use). Results are discussed alongside potential mechanisms of cannabis effects on cognition in HIV (e.g., anti-inflammatory), and considerations are outlined for screening PWH that may benefit from cannabis interventions. We further highlight the value of accelerating research discoveries in this area by utilizing translatable cross-species tasks to facilitate comparisons across human and animal work.

Changes in frequency of cannabis use among people with HIV during the COVID-19 pandemic: a multi-methods study to explore the underlying reasons for change

Background: People with HIV (PWH) report higher rates of cannabis use than the general population. It is unclear how cannabis use among PWH has been impacted by the COVID-19 pandemic and the implications for the health and wellbeing of PWH.Objectives: To describe changes in frequency of cannabis use among a sample of PWH during the pandemic, reasons for those changes, and implications of the findings.Methods: The data are cross-sectional and come from questions asked in a follow-up phone survey administered to a prospective cohort of PWH in Florida between May 2020 and March 2021. Participants who used cannabis were asked about changes in their frequency of cannabis use in a quantitative survey and reasons for changes in a qualitative open-ended question. Qualitative data were analyzed using thematic analysis.Results: Among 227 PWH (mean age 50, 50% men, 69% Black/African American, 14% Hispanic/Latino), 13% decreased frequency of cannabis, 11% increased frequency, and 76% reported no change. The most common reasons for increasing frequency of cannabis use were reducing anxiety/stress, trying to relax, coping with grief or reducing symptoms of depression, and reducing boredom during the pandemic. Supply or access issues, health concerns, and having already wanted to reduce cannabis use were common reasons for decreased frequency.Conclusion: Nearly 25% of the sample changed their cannabis use frequency during the pandemic. These findings shed light on the behaviors and motivations of PWH who use cannabis and can inform clinical practice and interventions during public health emergencies and beyond.

Substance Use and Depression Impede ART Adherence Among Female Sex Workers Living with HIV in the Dominican Republic

Female sex workers (FSW) have worse HIV outcomes in part due to lower anti-retroviral therapy (ART) adherence. Substance use and depression are important barriers to ART adherence, yet few studies have assessed these relationships among FSW in longitudinal studies. Cross-Lagged Panel Models and autoregressive mediation analyses assessed substance use (illicit drug use and alcohol use disorders) in relation to ART non-adherence and the mediation role of depressive symptoms among 240 FSW living with HIV in the Dominican Republic. In annual visits (T1, T2, T3), the majority (70%, 66%, and 53%) reported at-risk drinking and 15%, 13% and 9% used illicit drug during the past 6 months. Most FSW (70%, 62% and 46%) had mild-to-severe depression. Illicit drug use predicted later ART non-adherence. This relationship was not mediated via depressive symptoms. Integrated substance use and HIV care interventions are needed to promote ART adherence and viral suppression among FSW.

The neurocognitive effects of a past cannabis use disorder in a diverse sample of people living with HIV

People living with HIV (PLWH) report higher rates of cannabis use than the general population, a trend likely to continue in light of recent policy changes and the reported therapeutic benefits of cannabis for PLWH. Therefore, it is important to better understand cannabis-associated effects on neurocognition, especially as PLWH are at heightened risk for neurocognitive impairment. This study aimed to elucidate the effects of a past cannabis use disorder on current neurocognition in a diverse sample of PLWH. This cross-sectional study included 138 PLWH (age M(SD) = 47.28(8.06); education M(SD) = 12.64(2.73); 73% Male; 71% Latinx) who underwent neuropsychological, DSM-diagnostic, and urine toxicology evaluations. One-way ANCOVAs were conducted to examine effects of a past cannabis use disorder (CUD+) on tests of attention/working memory, processing speed, executive functioning, verbal fluency, learning, memory, and motor ability. Compared to the past CUD- group, the past CUD+ group performed significantly better on tests of processing speed, visual learning and memory, and motor ability (p's < .05). Findings suggest PLWH with past cannabis use have similar or better neurocognition across domains compared to PLWH without past use.

Cannabis use impacts pre-stimulus neural activity in the visual cortices of people with HIV

People with HIV (PWH) use cannabis at a higher rate than the general population, but the influence on neural activity is not well characterized. Cannabis use among PWH may have a beneficial effect, as neuroinflammation is known to be a critical problem in PWH and cannabis use has been associated with a reduction in proinflammatory markers. Thus, it is important to understand the net impact of cannabis use on brain and cognitive function in PWH. In this study, we collected magnetoencephalographic (MEG) brain imaging data on 81 participants split across four demographically matched groups (i.e., PWH using cannabis, controls using cannabis, non‐using PWH, and non‐using controls). Participants completed a visuospatial processing task during MEG. Time–frequency resolved voxel time series were extracted to identify the dynamics of oscillatory and pre‐stimulus baseline neural activity. Our results indicated strong theta (4–8 Hz), alpha (10–16 Hz), and gamma (62–72 Hz) visual oscillations in parietal–occipital brain regions across all participants. PWH exhibited significant behavioral deficits in visuospatial processing, as well as reduced theta oscillations and elevated pre‐stimulus gamma activity in visual cortices, all of which replicate prior work. Strikingly, chronic cannabis use was associated with a significant reduction in pre‐stimulus gamma activity in the visual cortices, such that PWH no longer statistically differed from controls. These results provide initial evidence that cannabis use may normalize some neural aberrations in PWH. This study fills an important gap in understanding the impact of cannabis use on brain and cognitive function in PWH.

Cannabis and Inflammation in HIV: A Review of Human and Animal Studies

Persistent inflammation occurs in people with HIV (PWH) and has many downstream adverse effects including myocardial infarction, neurocognitive impairment and death. Because the proportion of people with HIV who use cannabis is high and cannabis may be anti-inflammatory, it is important to characterize the impact of cannabis use on inflammation specifically in PWH. We performed a selective, non-exhaustive review of the literature on the effects of cannabis on inflammation in PWH. Research in this area suggests that cannabinoids are anti-inflammatory in the setting of HIV. Anti-inflammatory actions are mediated in many cases through effects on the endocannabinoid system (ECS) in the gut, and through stabilization of gut–blood barrier integrity. Cannabidiol may be particularly important as an anti-inflammatory cannabinoid. Cannabis may provide a beneficial intervention to reduce morbidity related to inflammation in PWH.

Confound, Cause, or Cure: The Effect of Cannabinoids on HIV-Associated Neurological Sequelae

The persistence of human immunodeficiency virus-1 (HIV)-associated neurocognitive disorders (HAND) in the era of effective antiretroviral therapy suggests that modern HIV neuropathogenesis is driven, at least in part, by mechanisms distinct from the viral life cycle. Identifying more subtle mechanisms is complicated by frequent comorbidities in HIV⁺ populations. One of the common confounds is substance abuse, with cannabis being the most frequently used psychoactive substance among people living with HIV. The psychoactive effects of cannabis use can themselves mimic, and perhaps magnify, the cognitive deficits observed in HAND; however, the neuromodulatory and anti-inflammatory properties of cannabinoids may counter HIV-induced excitotoxicity and neuroinflammation. Here, we review our understanding of the cross talk between HIV and cannabinoids in the central nervous system by exploring both clinical observations and evidence from preclinical in vivo and in vitro models. Additionally, we comment on recent advances in human, multi-cell in vitro systems that allow for more translatable, mechanistic studies of the relationship between cannabinoid pharmacology and this uniquely human virus.

Living With Chronic HIV Disease in the Antiretroviral Era: The Impact of Neurocognitive Impairment on Everyday Life Functions

Although there is extensive literature around the biologic correlations of neurocognitive function in HIV/AIDS, less is known about the impact in everyday living. We conducted a systematic review of the association of neurocognitive impairment with everyday life functions in people with HIV on antiretroviral therapy. We specifically focused on attention, executive function, processing speed, and the central executive component of the working memory. We considered 3 domains of everyday functions: (1) autonomy, (2) decision making and adherence to treatment, and (3) quality of life and psychologic wellbeing. The relationship between neurocognitive impairment and mental health was examined, given its correlation with everyday life functions. Results indicate that people with HIV do experience problems with autonomy of daily living (especially if aged older than 50 years) and with decision making, and neurocognitive impairment plays a role in this regard. Psychologic wellbeing is associated with executive function and processing speed. These patients may also have a reduced quality of life, but the relationship between quality of life and cognition is uncertain or could be mediated by other factors. Neurocognitive impairment correlates with depression and anxiety; however, the relationship of cognitive performance with apathy is still controversial.

Neuroimaging the Neuropathogenesis of HIV

PURPOSE OF REVIEW

This review highlights neuroimaging studies of HIV conducted over the last 2 years and discusses how relevant findings further our knowledge of the neuropathology of HIV. Three major avenues of neuroimaging research are covered with a particular emphasis on inflammation, aging, and substance use in persons living with HIV (PLWH).

RECENT FINDINGS

Neuroimaging has been a critical tool for understanding the neuropathological underpinnings observed in HIV. Recent studies comparing levels of neuroinflammation in PLWH and HIV-negative controls show inconsistent results but report an association between elevated neuroinflammation and poorer cognition in PLWH. Other recent neuroimaging studies suggest that older PLWH are at increased risk for brain and cognitive compromise compared to their younger counterparts. Finally, recent findings also suggest that the effects of HIV may be exacerbated by alcohol and drug abuse. These neuroimaging studies provide insight into the structural, functional, and molecular changes occurring in the brain due to HIV. HIV triggers a strong neuroimmune response and may lead to a cascade of events including increased chronic inflammation and cognitive decline. These outcomes are further exacerbated by age and age-related comorbidities, as well as lifestyle factors such as drug use/abuse.

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.

Impact of Cannabis Use on Brain Structure and Function in Suppressed HIV Infection

BACKGROUND

Brain atrophy and cognitive deficits persist among individuals with suppressed HIV disease. The impact of cannabis use is unknown.

METHODS

HIV+ and HIV- participants underwent cross-sectional magnetic resonance imaging and neuropsychological testing. Lifetime frequency, duration (years), and recency of cannabis use were self-reported. Relationships of cannabis use to resting-state functional connectivity (RSFC) and to 9 regional brain volumes were assessed with corrections for multiple comparisons. Peripheral blood cytokines and monocyte subsets were measured in the HIV+ group and examined in relation to cannabis exposure.

RESULTS

We evaluated 52 HIV+ [50.8 ± 7.1 years old; 100% on antiretroviral therapy ≥ 3 months; 83% with plasma viral load < 50 copies/mL] and 55 HIV- [54.0 ± 7.5 years old] individuals. Among HIV+ participants, recent cannabis use (within 12 months) was associated with diminished RSFC, including of occipital cortex, controlling for age. Duration of use correlated negatively with volumes of all regions (most strikingly the nucleus accumbens) independently of recent use and intracranial volume. Recent use was associated with larger caudate and white matter volumes and lower soluble vascular cell adhesion molecule-1 and monocyte chemoattractant protein-1 concentrations. Duration of use correlated positively with psychomotor speed. Use > 10 times/lifetime was linked to more somatic symptoms, better executive function, and lower CD14⁺CD16⁺⁺ monocyte count.

CONCLUSION

HIV+ individuals demonstrated opposing associations with cannabis. Recent use may weaken RSFC and prolonged consumption may exacerbate atrophy of the accumbens and other brain regions. More frequent or recent cannabis use may reduce the inflammation and CD14⁺CD16⁺⁺ monocytes that facilitate HIV neuroinvasion. HIV-specific cannabis studies are necessary.

Cannabis Consumption in People Living with HIV: Reasons for Use, Secondary Effects, and Opportunities for Health Education

Introduction: Rates of cannabis consumption range from 40% to 74% among people living with HIV (PLWH). Little is known about the reasons for cannabis use, related modes of administration, effectiveness for symptom relief, or undesirable effects in the modern antiretroviral therapy (ART) era. Our aim was to conduct an exploratory study to identify potential areas for further evaluation and intervention. Materials and Methods: From January to June 2018, health care providers at the Chronic Viral Illness Service in Montreal, Canada, asked their patients about cannabis use during routine visits. Patients reporting cannabis use were invited to complete a 20-min coordinator-administered questionnaire. Questions related to patterns of use, modes of administration, reasons for use, secondary effects, and HIV health-related factors (e.g., adherence to ART). Results: One hundred and four PLWH reporting cannabis use participated. Median age was 54 years (interquartile range [IQR] 46-59), 13% were female, and 42% were HIV-Hepatitis C co-infected. Median CD4 count was 590 cells/mm³ (IQR 390-821), 95% of participants were on ART, and 88% had suppressed viral loads. Reported cannabis use was more than once daily (32%); daily (25%); weekly (22%); monthly (17%); and rarely (twice to thrice per year; 6%). The majority of participants (97%) smoked dry plant cannabis. Other modes included vaping (12%), capsules (2%), edibles (21%), and oils (12%). Common reasons for cannabis use were for pleasure (68%) and to reduce anxiety (57%), stress (55%), and pain (57%). Many participants found cannabis "quite effective" or "extremely effective" (45%) for symptom relief. Secondary effects included feeling high (74%), increased cough (45%), paranoia (22%), palpitations (20%), and increased anxiety (21%). Over two-thirds of participants indicated that secondary effects were not bothersome at all. Most participants (68%) rarely missed doses of their ART, while 27% missed occasionally (once to twice per month). The most commonly accessed sources of information about cannabis were friends (77%) and the internet (55%). Conclusion: The most common reasons for cannabis use in our population were for pleasure, followed by reduction of stress/anxiety and symptoms associated with a medical condition. Most smoke cannabis and rate cannabis as quite effective for symptom relief. While many participants experience secondary effects, most are not bothered by these symptoms. Amid widespread changes in the regulatory landscape of recreational cannabis, health care providers should be prepared to answer questions about cannabis.

Association of Marijuana Use with Changes in Cognitive Processing Speed and Flexibility for 17 Years in HIV-Seropositive and HIV-Seronegative Men

BACKGROUND

The long-term effects of marijuana on cognition, particularly in the context of HIV is not clear, as extant research shows mixed findings.

OBJECTIVE

To determine associations between current and cumulative exposure to marijuana and changes in cognitive processing speed and flexibility in 788 HIV-seropositive (HIV+) and 1,132 HIV-seronegative (HIV-) men followed for up to 17 years in the Multicenter AIDS Cohort Study.

RESULTS

Among HIV+ men only, current daily marijuana use compared to none-use, was significantly associated with a greater annual percentage decline in cognitive processing speed assessed with the Trail Making Test A (TMTA) (β=-0.41, 95% confidence interval (CI): -0.88, -0.03, p=0.03)] and Symbol Digit Modalities Test (SDMT) (β= -0.14, 95% CI: -0.28, -0.01, p=0.04). Further, monthly marijuana use was associated with greater annual percentage decline in cognitive flexibility assessed with the Trail Making Test B (TMTB) (β= -0.70, 95% CI: -1.34, -0.05; p=0.03] and cognitive processing speed (SDMT) (β= -0.21, 95% CI: -0.40, -0.01, p=0.03). Among the HIV- men only, each 5-marijuana use-years (equivalent to 5-years of daily marijuana use) was significantly associated with a 0.17 annual percentage decline in cognitive processing speed only (TMTA) (β= -0.18, 95% CI: -0.36, -0.01; p=0.04).

CONCLUSIONS

Our findings suggest that marijuana use, particularly current use, may be associated with worse cognitive processing speed, but the magnitude of the estimates was not clinically meaningful.