An Update of the Review of Neuropsychological Consequences of HIV and Substance Abuse: A Literature Review and Implications for Treatment and Future Research

HIV chronicity as a predictor of hippocampal memory deficits in daily cannabis users living with HIV

Background

Antiretroviral medications have increased the lifespan of persons living with HIV (PLWH) thereby unmasking memory decline that may be attributed to chronological age, HIV symptomatology, HIV disease chronicity, and/or substance use (especially cannabis use which is common among PLWH). To date, few studies have attempted to disentangle these effects. In a sample of daily cannabis-using PLWH, we investigated whether hippocampal memory function, assessed via an object-location associative learning task, was associated with age, HIV chronicity and symptom severity, or substance use.

Methods

48 PLWH (12.9 ± 9.6 years since HIV diagnosis), who were 44 years old on average (range: 24-64 years; 58 % male) and reported daily cannabis use (recent use confirmed by urinalysis) completed the study. We assessed each participant's demographics, substance use, medical history, current HIV symptoms, and hippocampal memory function via a well-validated object-location associative learning task.

Results

Multiple regression analyses found that living more years since HIV+ diagnosis predicted significantly worse associative learning total score (r=-0.40) and learning rate (r=-0.34) whereas chronological age, cannabis-use characteristics, and recent HIV symptom severity were not significantly related to hippocampal memory function.

Conclusions

In daily cannabis-using PLWH, HIV chronicity was related to worse hippocampal memory function independent from cannabis use, age, and HIV symptomatology. Object-location associative learning performance could serve as an 'early-warning' metric of cognitive decline among PLWH. Future research should examine longitudinal changes in associative learning proficiency and evaluate interventions to prevent hippocampal memory decline among PLWH. ClinicalTrials.gov: NCT01536899.

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.

The Combined Effects of Cannabis, Methamphetamine, and HIV on Neurocognition

OBJECTIVE

Methamphetamine and cannabis are two widely used substances among people living with HIV (PLWH). Whereas methamphetamine use has been found to worsen HIV-associated neurocognitive impairment, the effects of combined cannabis and methamphetamine use disorder on neurocognition in PLWH are not understood. In the present study, we aimed to determine the influence of these substance use disorders on neurocognition in PLWH and to explore if methamphetamine-cannabis effects interacted with HIV status.

METHOD AND PARTICIPANTS

After completing a comprehensive neurobehavioral assessment, PLWH (n = 472) were stratified by lifetime methamphetamine (M-/M+) and cannabis (C-/C+) DSM-IV abuse/dependence disorder into four groups: M-C- (n = 187), M-C+ (n = 68), M+C-, (n = 82), and M+C+ (n = 135). Group differences in global and domain neurocognitive performances and impairment were examined using multiple linear and logistic regression, respectively, while holding constant other covariates that were associated with study groups and/or cognition. Data from participants without HIV (n = 423) were added, and mixed-effect models were used to examine possible interactions between HIV and substance use disorders on neurocognition.

RESULTS

Compared with M+C+, M+C- performed worse on measures of executive functions, learning, memory, and working memory and were more likely to be classified as impaired in those domains. M-C- performed better than M+C+ on measures of learning and memory but worse than M-C+ on measures of executive functions, learning, memory, and working memory. Detectable plasma HIV RNA and nadir CD4 < 200 were associated with lower overall neurocognitive performance, and these effects were greater for M+C+ compared with M-C-.

CONCLUSIONS

In PLWH, lifetime methamphetamine use disorder and both current and legacy markers of HIV disease severity are associated with worse neurocognitive outcomes. There was no evidence of an HIV × M+ interaction across groups, but neurocognition was most impacted by HIV among those with polysubstance use disorder (M+C+). Better performance by C+ groups is consistent with findings from preclinical studies that cannabis use may protect against methamphetamine's deleterious effects.

Impaired verbal memory in individuals living with HIV and cocaine dependence

INTRODUCTION

Our study aimed to understand the independent and combined effects of cocaine dependence and HIV status across aspects of verbal memory.

METHOD

Our sample consisted of a total of 102 individuals: 28 individuals living with HIV and cocaine dependence (HIV+/CD), 28 individuals who are HIV-negative with cocaine dependence (HIV-/CD), 20 individuals living with HIV without cocaine dependence (HIV+/ND), and 26 individuals who are HIV-negative without cocaine dependence (HIV-/ND). We utilized the Hopkins Verbal Learning Test-Revised Version (HVLT-R) to assess components of verbal memory, including encoding, recall, and recognition. A 2 (HIV: Yes/No) × 2 (Cocaine: Yes/No) MANCOVA on Total and Delayed Recall while controlling for premorbid intelligence was conducted. We used a Kruskal-Wallis H test to examine retrieval and recognition.

RESULTS

The combination of HIV and cocaine dependence amplified deficits on Total Recall. We found comparably poor performance across Delayed Recall between all three clinical groups. People living with HIV without cocaine dependence demonstrated intact recognition, whereas those with cocaine dependence had poor recognition.

CONCLUSIONS

HIV and cocaine both impacted verbal memory. However, there are potential subtle differences in the role cocaine versus HIV has on the memory process. People living with HIV without cocaine dependence recognized significantly more words than they could freely recall. In contrast, cocaine dependence impacted recognition in HIV and non-HIV groups. These performance patterns suggest HIV may be associated with retrieval deficits, whereas cocaine dependence may be associated with encoding deficits. Further research assessing these specific components of the memory process will help clarify these potential differences.

Central Nervous System Effects of COVID-19 in People with HIV Infection

The convergence of the HIV and SARS-CoV-2 pandemics is an emerging field of interest. In this review, we outline the central nervous system (CNS) effects of COVID-19 in the general population and how these effects may manifest in people with HIV (PWH). We discuss the hypothetical mechanisms through which SARS-CoV-2 could impact the CNS during both the acute and recovery phases of infection and the potential selective vulnerability of PWH to these effects as a result of epidemiologic, clinical, and biologic factors. Finally, we define key research questions and considerations for the investigation of CNS sequelae of COVID-19 in PWH.

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.

Neuroimaging and Cognitive Evidence for Combined HIV-Alcohol Effects on the Central Nervous System: A Review

Alcohol use disorder (AUD) among people living with HIV (PLWH) is a significant public health concern. Despite the advent of effective antiretroviral therapy, up to 50% of PLWH still experience worsened neurocognition, which comorbid AUD exacerbates. We report converging lines of neuroimaging and neuropsychological evidence linking comorbid HIV/AUD to dysfunction in brain regions linked to executive function, learning and memory, processing speed, and motor control, and consequently to impairment in daily life. The brain shrinkage, functional network alterations, and brain metabolite disruption seen in individuals with HIV/AUD have been attributed to several interacting pathways: viral proteins and EtOH are directly neurotoxic and exacerbate each other's neurotoxic effects; EtOH reduces antiretroviral adherence and increases viral replication; AUD and HIV both increase gut microbial translocation, promoting systemic inflammation and HIV transport into the brain by immune cells; and HIV may compound alcohol's damaging effects on the liver, further increasing inflammation. We additionally review the neurocognitive effects of aging, Hepatitis C coinfection, obesity, and cardiovascular disease, tobacco use, and nutritional deficiencies, all of which have been shown to compound cognitive changes in HIV, AUD, and in their comorbidity. Finally, we examine emerging questions in HIV/AUD research, including genetic and cognitive protective factors, the role of binge drinking in HIV/AUD-linked cognitive decline, and whether neurocognitive and brain functions normalize after drinking cessation.

HIV Neuropathogenesis in the Presence of a Disrupted Dopamine System

Antiretroviral therapy (ART) has transformed HIV into a chronic condition, lengthening and improving the lives of individuals living with this virus. Despite successful suppression of HIV replication, people living with HIV (PLWH) are susceptible to a growing number of comorbidities, including neuroHIV that results from infection of the central nervous system (CNS). Alterations in the dopaminergic system have long been associated with HIV infection of the CNS. Studies indicate that changes in dopamine concentrations not only alter neurotransmission, but also significantly impact the function of immune cells, contributing to neuroinflammation and neuronal dysfunction. Monocytes/macrophages, which are a major target for HIV in the CNS, are responsive to dopamine. Therefore, defining more precisely the mechanisms by which dopamine acts on these cells, and the changes in cellular function elicited by this neurotransmitter are necessary to develop therapeutic strategies to treat neuroHIV. This is especially important for vulnerable populations of PLWH with chemically altered dopamine concentrations, such as individuals with substance use disorder (SUD), or aging individuals using dopamine-altering medications. The specific neuropathologic and neurocognitive consequences of increased CNS dopamine remain unclear. This is due to the complex nature of HIV neuropathogenesis, and logistical and technical challenges that contribute to inconsistencies among cohort studies, animal models and in vitro studies, as well as lack of demographic data and access to human CNS samples and cells. This review summarizes current understanding of the impact of dopamine on HIV neuropathogenesis, and proposes new experimental approaches to examine the role of dopamine in CNS HIV infection. Graphical abstract HIV Neuropathogenesis in the Presence of a Disrupted Dopamine System. Both substance abuse disorders and the use of dopaminergic medications for age-related diseases are associated with changes in CNS dopamine concentrations and dopaminergic neurotransmission. These changes can lead to aberrant immune function, particularly in myeloid cells, which contributes to the neuroinflammation, neuropathology and dysfunctional neurotransmission observed in dopamine-rich regions in HIV+ individuals. These changes, which are seen despite the use antiretroviral therapy (ART), in turn lead to further dysregulation of the dopamine system. Thus, in individuals with elevated dopamine, the bi-directional interaction between aberrant dopaminergic neurotransmission and HIV infection creates a feedback loop contributing to HIV associated neurocognitive dysfunction and neuroHIV. However, the distinct contributions and interactions made by HIV infection, inflammatory mediators, ART, drugs of abuse, and age-related therapeutics are poorly understood. Defining more precisely the mechanisms by which these factors influence the development of neurological disease is critical to addressing the continued presence of neuroHIV in vulnerable populations, such as HIV-infected older adults or drug abusers. Due to the complexity of this system, understanding these effects will require a combination of novel experimental modalities in the context of ART. These will include more rigorous epidemiological studies, relevant animal models, and in vitro cellular and molecular mechanistic analysis.

Sustained attention and vigilance deficits associated with HIV and a history of methamphetamine dependence

BACKGROUND

Human immunodeficiency virus (HIV)-associated neurocognitive disorders persist in the era of antiretroviral therapy. One factor that is elevated among persons with HIV (PWH) and independently associated with neurocognitive impairment is methamphetamine dependence (METH). Such dependence may further increase cognitive impairment among PWH, by delaying HIV diagnosis (and thus, antiretroviral therapy initiation), which has been posited to account for persistent cognitive impairment among PWH, despite subsequent treatment-related viral load suppression (VLS; <50 copies of the virus per milliliter in plasma or cerebrospinal fluid). This study examined the main and interactive (additive versus synergistic) effects of HIV and history of METH on the sustained attention and vigilance cognitive domain, while controlling for VLS.

METHODS

Participants included 205 (median age = 44 years; 77% males; HIV-/METH- n = 67; HIV+/METH - n = 49; HIV-/METH+ n = 36; HIV+/METH+ n = 53) individuals enrolled in the Translational Methamphetamine AIDS Research Center, who completed Conners' and the 5-Choice continuous performance tests (CPTs).

RESULTS

METH participants exhibited deficits in sustained attention and vigilance; however, these effects were not significant after excluding participants who had a positive urine toxicology screen for methamphetamine. Controlling for VLS, PWH did not have worse sustained attention and vigilance, but consistently displayed slower reaction times across blocks, relative to HIV- participants. There was no HIV x METH interaction on sustained attention and vigilance.

CONCLUSIONS

Recent methamphetamine use among METH people and detectable viral loads are detrimental to sustained attention and vigilance. These findings highlight the need for prompt diagnosis of HIV and initiation of antiretroviral therapy, and METH use interventions.

Syndemic factors associated with adherence to antiretroviral therapy among HIV-positive adult heterosexual men

BACKGROUND

Suboptimal adherence to HIV antiretroviral therapy (ART) and concomitant lack of viral control can have severe consequences for health and onward transmission among persons living with HIV. Little is known about the barriers and facilitators of optimal ART adherence among heterosexual HIV-positive men.

METHODS

Structural equation modeling (SEM) was performed to test a theory-derived model of ART adherence using data from a cross-sectional sample of 317 HIV-positive self-identified heterosexual men residing in New York City. We assessed a conceptual model in which mental health (depression, anxiety) and substance use dependence mediated the effects of socio-structural factors (HIV-related stigma, social support) on ART adherence, and subsequently, undetectable viral load.

RESULTS

Structural equation modeling analyses indicated that men who reported higher levels of HIV-related stigma tended to experience higher levels of general anxiety, which in turn was associated with reduced probability of optimal ART adherence. Moreover, men who reported higher levels of social support tended to exhibit less dependence on illicit substance use, which in turn was associated with increased probability of optimal ART adherence. African-American men reported lower ART adherence compared to other racial/ethnic groups.

CONCLUSIONS

Our findings support the hypothesis that substance use dependence and mental health problems, particularly anxiety, may be primary drivers of suboptimal ART adherence among heterosexual men, and that socio-structural factors such as HIV-related stigma and social support are potential modifiable antecedents of these drivers.

Differential relationships between cannabis consumption and sleep health as a function of HIV status

BACKGROUND

There is evidence that regular cannabis use has negative effects on sleep health. Relative to HIV- populations, HIV + individuals consistently report greater sleep impairments. The number of HIV + individuals reporting frequent cannabis use, often to treat sleep issues, has significantly increased recently. It is unknown, however, if HIV status moderates the association between cannabis use and sleep health. The current study, therefore, examines these associations in a sample of HIV + and HIV- adults.

METHODS

HIV + and HIV- (N = 107) individuals completed one laboratory visit. Participants completed a 30-day drug use history questionnaire quantifying consumption of cannabis, cigarettes, and alcohol, and a sleep health questionnaire. To verify substance use and HIV status, participants completed a urine toxicology screening and serology testing.

RESULTS

HIV + individuals demonstrated lower sleep health than HIV- individuals. Linear regressions indicated that HIV status moderated the association between total 30-day cannabis consumption and sleep health; cannabis consumption was negatively associated with sleep health in HIV-, but not HIV + individuals. This interactive effect was significant after examining cigarette/alcohol use, depression symptoms, and demographic variables as covariates.

CONCLUSIONS

These results corroborate studies demonstrating an inverse relationship between sleep health and cannabis consumption. This study also suggests that factors other than cannabis may be associated with lower sleep health in HIV + individuals. Emerging studies suggest that inflammation may mediate effects of cannabis on HIV infection. Future studies examining this mechanism are warranted to understand cannabis further and sleep in HIV + individuals.

Integration of Neuropsychological Services in a VA HIV Primary Care Clinic

The Department of Veteran Affairs (VA) is the largest health care provider for individuals with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), with >28,000 Veterans with HIV/AIDS enrolled in care. Advances in medical treatment have improved the life-limiting effects of the disease, though many chronic symptoms persist. Comprehensive care is critical to manage the diverse constellation of symptoms. However, many patients face challenges to receiving optimal care due to limited resources, mistrust of health care providers, and/or co-occurring medical, psychiatric, and substance use disorders. The VA is a leader in developing integrated models of care to address these barriers. The inclusion of subspecialty mental health and substance abuse treatment in HIV care has been implemented across many VAs, with evidence of improved patient outcomes. However, neuropsychology has not traditionally been included, despite the fact that cognitive dysfunction represents one of the most ubiquitous complications of HIV/AIDS. Cognitive impairment is associated with myriad negative outcomes including medication non-adherence, reduced quality of life, and increased mortality. We contend that neuropsychologists are uniquely equipped to contribute to the comprehensive care of patients with HIV/AIDS. Neuropsychologists understand the range of factors that can impact cognition and have the requisite knowledge and skills to assess and treat cognitive dysfunction. Although we focus on HIV/AIDS, neuropsychologists often play critical roles in the provision of care for other infectious diseases (e.g., hepatitis C).

Cognitive Decline in Relation to Psychological Wellbeing and HIV Disease- and Treatment Characteristics in HIV-Infected Patients on cART: A One-Year Follow-Up Study

The objectives of the current study were to examine cognitive decline in relation to psychological wellbeing, HIV disease and treatment characteristics and baseline variables over a one-year period of time in a group of HIV-infected patients on long term cART with undetectable viral load in comparison to a HIV-negative control group. Eighty-two of 95 patients and 43 of 55 controls who completed a baseline assessment for the Art-NeCo study underwent a follow-up neuropsychological assessment. A repeated-measure general linear model analysis was performed to compare the performance at follow-up in comparison to baseline between the patients and controls. Reliable change indices were computed as a measure of significant change in cognitive function. Compared to controls, patients overall performed worse on the domain speed of information processing. In the patient group a worse performance at follow-up was present for the verbal fluency domain compared to the controls, in the absence of a baseline group difference. For the executive function domain, no group differences were found at follow-up, but the patients performed worse than the controls at baseline. We found that cognitive decline was related to more frequent use of recreational drugs and a somewhat heightened level of irritability and more somatic complaints at baseline. However, the decliners did not differ from the non-decliners on any of the HIV-related variables.

[Differential diagnostics of dementia type diseases]

Dementia remains the most common neuropsychiatric disease in elderly people. This is not only a great burden for the affected person, but also for the entire society. Currently, it is estimated that more than one million people in Germany suffer from dementia. The incidence is about 244,000 people per year. There are different forms of dementia. Primary dementia is caused by neurodegenerative or vascular diseases. Approximately 90% of all dementia types in people over 65 years of age are primary. Secondary dementia includes organic illness, which leads to dementing syndromes. Traumatic brain injury, tumor, medication and toxic substances, for instance, belong to these. Usually, if the underlying disease can be treated effectively, mental performance and cognition can be returned to normal.