Social Isolation Is Linked to Inflammation in Aging People With HIV and Uninfected Individuals

BACKGROUND

Even in the era of suppressive antiretroviral therapy, people with HIV (PWH) suffer greater exposure to inflammation than their uninfected peers. Although poor social support and social isolation have been linked to systemic inflammation in the general population, it is not known whether this is true also among PWH.

METHODS

People with and without HIV infection were enrolled in a community-based, single-center study. Primary predictors were the Medical Outcomes Study Social Support Survey, and outcomes were a panel of inflammatory biomarkers (ICAM-1, MCP-1, IL-6, IL-8, IP-10, C-reactive protein, D-dimer, VEGF, sCD14, and uPAR) in blood plasma and cerebrospinal fluid (CSF).

RESULTS

PWH had worse positive social support (P = 0.0138) and affectionate support (P = 0.0078) than did HIV- individuals. A factor analysis was used to group the biomarkers into related categories separately for each fluid. Levels of 3 of the 4 plasma factors were significantly higher in PWH than HIV- (ps = 0.007, 0.001, and 0.0005, respectively). Levels of 1 of the 3 CSF factors also were significantly higher in PWH than HIV- (P = 0.0194). In the combined PWH and HIV- cohort, poorer social support was associated with higher levels of a factor in plasma loading on MCP-1, IL-8, and VEGF (P = 0.020) and with a CSF factor loading on MCP-1 and IL-6 (P = 0.006).

CONCLUSION

These results suggest that enhancing social support might be an intervention to reduce inflammation and its associated adverse outcomes among PWH.

Both HIV and Tat expression decrease prepulse inhibition with further impairment by methamphetamine

HIV infection and methamphetamine (METH) use are highly comorbid and represent a significant public health problem. Both conditions are known to negatively impact a variety of brain functions. One brain function that may be affected by HIV and METH use is sensorimotor gating, an automatic, pre-conscious filtering of sensory information that is thought to contribute to higher order cognitive processes. Sensorimotor gating is often measured using prepulse inhibition (PPI), a paradigm that can be conducted in both humans and animals, thereby enabling cross-species translational studies. While previous studies suggest HIV and METH may individually impair PPI, little research has been conducted on the effects of combined HIV and METH on PPI. The goal of this cross-species study was to determine the effects of METH on PPI in the inducible Tat (iTat) mouse model of HIV and in people with HIV. PPI was measured in the iTat mouse model before, during, and after chronic METH treatment and after Tat induction. Chronic METH treatment decreased PPI in male but not female mice. PPI normalized with cessation of METH. Inducing Tat expression decreased PPI in male but not in female mice. No interactions between chronic METH treatment and Tat expression were observed in mice. In humans, HIV was associated with decreased PPI in both men and women. Furthermore, PPI was lowest in people with HIV who also had a history of METH dependence. Overall, these results suggest HIV and METH may additively impair early information processing in humans, potentially affecting downstream cognitive function.

Gut microbiota dysbiosis is associated with worse emotional states in HIV infection

The biological mechanisms underlying emotional distress in HIV infection are likely to be complex but remain understudied. We investigated whether dysbiotic signatures in the gut microbiome of persons living with HIV (PLWH) are associated with their emotional status. We retrospectively examined the gut microbiome and clinical evaluation of 129 adults (94 PLWH and 35 HIV-) enrolled at UC San Diego's HIV Neurobehavioral Research Program. A subset of participants (32 PLWH vs. 13 HIV-) underwent an emotional assessment using the NIH Toolbox Emotion Battery summarized by three composite scores (negative affect, social satisfaction, and psychological well-being). We then sequenced the 16S rDNA V3-V4 regions from stool and performed taxonomic assignment using CLC Microbial Genomics Module. The gut microbiota profiles were evaluated in relation to participants' emotional assessment. All analyses were done in R statistical software. We found that the relative abundance of aerotolerant bacteria was significantly higher in PLWH (p < 0.01) and was associated with a lifetime major depression diagnosis independently of HIV status (p = 0.05). Moreover, PLWH experienced significantly worse psychological well-being (p = 0.02), less social satisfaction (p = 0.03), and more negative affect (p = 0.02). Higher levels of aerotolerant bacteria were associated with worse psychological well-being (rho = -0.35, p = 0.02), less social satisfaction (r = - 0.42, p < 0.01), and more negative affect (rho = 0.46, p < 0.01). The association of aerotolerant bacteria with social satisfaction and negative affect was independent of HIV status (p < 0.05, for both). The over-representation of aerotolerant bacteria in the gut may reflect worse oxidative stress and barrier defects and may contribute to emotional distress during HIV infection.

Metabolic Risk Factors as Differential Predictors of Profiles of Neurocognitive Impairment Among Older HIV+ and HIV- Adults: An Observational Study

OBJECTIVE

Neurocognitive performance among older persons, including those living with HIV (people living with HIV [PLWH]), exhibits significant heterogeneity, suggesting subpopulations with differing profiles of neurocognitive impairment (NCI). Metabolic factors are associated with NCI, but their relationships to cluster-derived NCI profiles are unknown.

METHOD

Participants (144 PLWH and 102 HIV uninfected) aged 50+ years completed a neuropsychological battery assessing seven cognitive domains. Latent class analysis (LCA) identified NCI profiles separately by HIV serostatus and in a combined sample. Obtained classes were examined against the Montreal Cognitive Assessment (MoCA) and diagnoses of HIV-associated neurocognitive disorders (HAND). Multinomial regression identified metabolic predictors of classification.

RESULTS

LCA identified three latent classes in each participant sample: Class1Multidomain NCI (high probability of impairment across multiple domains), Class 2Learning & Recall NCI (high probability of impairment in learning and recall), and Class 3NC Unimpaired (low probability of NCI across all domains). Severity of NCI implied by classes corresponded with MoCA scores and HAND diagnoses. In analyses on the combined sample, compared to HIV-uninfected individuals, PLWH were more likely to be in Class1Multidomain NCI. Among PLWH, those with dyslipidemia and hypertension had greater odds of classification in Class 1Multidomain NCI while those with central obesity had higher odds of classification in Class 2Learning & Recall NCI; metabolic syndrome approached significance as a differential predictor. Regardless of HIV status, individuals with diabetes were more likely to be in Class 1Multidomain NCI.

CONCLUSIONS

Metabolic risk factors confer heightened risk of NCI in HIV infection. Interventions to reduce metabolic risk may improve neurocognitive outcomes among PLWH.

Demographically adjusted normative data for the Wisconsin Card Sorting Test-64 item: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project

OBJECTIVE

The Wisconsin Card Sorting Test (WCST) is among the most commonly used tests of executive functioning. We aimed to generate normative data on the 64-item version of this test (WCST-64) for Spanish-speakers living in the U.S.-Mexico Border region.

METHODS

Participants included 189 native Spanish-speakers (Age: 19-60; Education: 0-20; 59.3% female) from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project who completed the WCST-64. Univariable and interactive associations between demographic variables and raw scores were examined via Spearman correlations, Wilcoxon Rank-sum tests and linear regressions. T-scores for various WCST-64 measures (Total Errors, Perseverative Responses, Perseverative Errors, Conceptual Level Responses and Number of Categories) were obtained using fractional polynomial equations with weights for age, education, and gender. Percentile scores were reported for Failures to Maintain Set. Rates of impairment (T-score < 40) were calculated by applying the newly developed norms and published norms for non-Hispanic English-speaking Whites and Blacks.

RESULTS

Older age was associated with worse performance and education was linked to better performance on most WCST-64 raw scores, with stronger education effects among females than males. The norms developed here resulted in expected rates of impairment (14-16% across measures). Applying published norms for non-Hispanic Blacks resulted in generally comparable impairment rates. In contrast, applying previously published norms for non-Hispanic Whites overestimated impairment (38-52% across measures).

CONCLUSIONS

These data will enhance interpretation performance on the WCST-64 for Spanish-speakers living in the U.S.-Mexico Border region. Future work will need to examine the generalizability of these norms to other Hispanic/Latino groups.

Demographically-adjusted norms for the processing speed subtests of the WAIS-III in a Spanish-speaking adult population: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project

OBJECTIVE

The Wechsler Adult Intelligence Scale (WAIS) processing speed subtests are among the most ubiquitous indices of processing speed in the field. The aim of this study was to develop and examine demographically-adjusted normative data for Spanish language versions of the WAIS-III Digit Symbol Coding (DSC) and Symbol Search (SS) subtests for US-dwelling Spanish-speakers living in the US/Mexico border region.

METHODS

The sample included 203 healthy participants who were part of the larger Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project (DSC: n = 201; SS: n = 200).

RESULTS

Older age and higher education were both related to lower scores on the DSC and SS subtests (all ps < .0001). There were no significant effects for gender (all ps > .05). Raw-to-scaled score conversions were calculated for both subtests, and fractional polynomial equations were derived to compute demographically-adjusted T-scores accounting for age, education, and gender for each subtest and the Processing Speed Index. Published norms for English-speaking non-Hispanic white adults slightly overestimated impairment rates (T-scores <40) on both the DSC and SS subtests, while the norms for English-speaking non-Hispanic Black/African Americans and the new NP-NUMBRS norms Spanish-speakers both yielded impairment rates that fell within expected limits for healthy controls (i.e. 13%-14%).

CONCLUSIONS

This study suggests that population-specific normative data can improve the diagnostic validity of these measures for U.S.-dwelling Spanish-speakers living in the US/Mexico border region. Future research is needed to investigate the utility of these norms for other U.S.-dwelling Spanish-speaking subpopulations (e.g. Caribbean, Central American, South American).

The Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project: Overview and considerations for life span research and evidence-based practice

OBJECTIVE

This paper summarizes the findings of the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project and offers a roadmap for future research.

METHODS

The NP-NUMBRS project represents the largest and most comprehensive co-normed neuropsychological battery to date for native Spanish-speaking healthy adults from the U.S. (California/Arizona)-Mexico borderland region (N = 254; ages 19-60 years). These norms provide demographic adjustments for tests across numerous domains (i.e., verbal fluency, processing speed, attention/working memory, executive function, episodic memory [learning and delayed recall], visuospatial, and fine motor skills).

CONCLUSIONS

This project: 1) shows that the NP-NUMBRS norms consistently outperformed previously published norms for English-speaking non-Hispanic (White and African-American) adults in identifying impairment; 2) explores the role of Spanish-English bilingualism in test performance; and 3) provides support for the diagnostic validity of these norms in detecting HIV-associated neurocognitive impairment. Study limitations include the limited assessment of sociocultural variables and generalizability (e.g., other Latina/o populations, age limit [19 - 60 years]). Future research is needed to: 1) investigate these norms with U.S.-dwelling Spanish-speakers of non-Mexican heritage and other clinical subpopulations; 2) expand coverage of cognitive domains (e.g. language, visuospatial); 3) develop large normative datasets for children and older Latina/o populations; 4) examine how sociocultural factors impact performance (e.g., bilingualism, acculturation); 5) investigate these norms' diagnostic and ecological validity; and 6) develop norms for neurocognitive change across time. It is hoped that the NP-NUMBRS norms will aid researchers and clinicians working with U.S.-dwelling Spanish-speakers from the U.S.-Mexico borderland to conduct research and evidence-based neuropsychological evaluations in a more culturally responsive and ethical manner.

Demographically adjusted norms for the Trail Making Test in native Spanish speakers: Results from the neuropsychological norms for the US-Mexico border region in Spanish (NP-NUMBRS) project

OBJECTIVE

Despite the wide use of the Trail Making Test (TMT), there is a lack of normative data for Spanish speakers living in the USA. Here we describe the development of regional norms for the TMT for native Spanish speakers residing in the Southwest Mexico-Border Region of the USA.

METHOD

Participants were 252 healthy native Spanish speakers, 58% women, from ages 19 to 60, and ranging in education from 0 to 20 years, recruited in San Diego, CA and Tucson, AZ. All completed the TMT in Spanish along with a comprehensive neuropsychological test battery as part of their participation in the Neuropsychological Norms for the US-Mexico Border Region in Spanish (NP-NUMBRS) project. Univariable and interactive effects of demographics on test performance were examined. T-scores were calculated using fractional polynomial equations to account for linear and any non-linear effects of age, education, and sex.

RESULTS

Older age and lower education were associated with worse scores on both TMT A and B. No sex differences were found. The newly derived T-scores showed no association with demographic variables and displayed the expected 16% rates of impairment using a -1 SD cut point based on a normal distribution. By comparison, published norms for English-speaking non-Hispanic Whites applied to the current data yielded significantly higher impairment for both TMT A and B with more comparable rates using non-Hispanic African Americans norms.

CONCLUSIONS

Population-specific, demographically adjusted regional norms improve the utility and diagnostic accuracy of the TMT for use with native Spanish speakers in the US-Mexico Border region.

The state of neuropsychological test norms for Spanish-speaking adults in the United States

Objective: The present review paper aimed to identify published neuropsychological test norms developed for Spanish-speakers living in the United States (U.S.). Methods: We conducted a systematic review of the literature via an electronic search on PubMed using keywords "Normative data," "Neuropsychological test," "norms", "Hispanic/Latinos," "Spanish Speakers," and "United States." We added other studies and published manuals as identified by citations in papers from the original search. Results Eighteen sources of normative data for Spanish-speakers in the U.S. were identified. Of the 18 citations identified, only four provide normative data on comprehensive batteries of tests for Spanish-Speakers. Two of these are based on persons living in the southwest of the U.S., who tend to be of Mexican origin. Overall, a number of the studies are focused on older persons and although the majority include participants with wide ranges of education, participants in the ends of the education distribution tend to be underrepresented. Conclusion: Here we provide a detailed description of the neuropsychological normative data currently available for Spanish-speakers living in the U.S. While there has been increased attention towards developing norms for neuropsychological batteries in Spanish-speaking countries (e.g., Latin America and Spain), there is still an urgent need to standardize neuropsychological tests among diverse groups of Spanish-speaking adults living in the U.S. The present review presents a list of norms for U.S.-dwelling Spanish-speakers, thus providing an important tool for clinicians and researchers.

Demographically-adjusted norms for the paced auditory serial addition test and letter number sequencing test in Spanish-speaking adults: Results from the neuropsychological norms for the U.S.-Mexico border region in Spanish (NP-NUMBRS) Project

OBJECTIVE

The Paced Auditory Serial Addition Test (PASAT) and Wechsler Adult Intelligence Scale Letter Number Sequencing subtest (LNS) are two commonly used measures of working memory. Demographic variables (age, education, ethnicity, etc.) can impact performance on these measures, underscoring the need for demographically adjusted norms. We aimed to develop normative data for the PASAT and LNS for Spanish-speaking adults living in the U.S.-Mexico border region as part of a larger normative effort.

METHOD

Participants were native Spanish-speakers from the Neuropsychological Norms for the U.S. Mexico Border Region in Spanish (NP-NUMBRS) project. Two hundred and forty-nine participants completed the PASAT and 202 participants completed LNS. Ages ranged from 19 to 60 and education from 0 to 20 years.

RESULTS

Older age was associated with lower scores on LNS (p < .01) but not PASAT. Lower education was associated with lower scores on both tests (ps < .001). Women obtained lower raw scores than men on PASAT (ps < .003), and there were no significant main effects of gender on LNS raw scores. Raw-to-scaled score conversions were calculated, and fractional polynomial equations were developed to calculate demographically-adjusted T-scores accounting for age, education, and gender. Published norms for English-speaking non-Hispanic Whites substantially overestimated rates of impairment (defined as T-score < 40) on both the PASAT and LNS.

CONCLUSIONS

The use of the population-specific normative data may improve detection of working memory dysfunction in U.S. Spanish-speaking adults and contribute to improved diagnostic accuracy and treatment planning in this population. Whether the norms generalize to U.S. Spanish-speakers from other countries remains to be determined.

Chronically elevated depressive symptoms interact with acute increases in inflammation to predict worse neurocognition among people with HIV

We examined the joint effects of depressive symptoms (Beck Depression Inventory-II (BDI-II)) and systemic inflammation (plasma C-reactive protein (CRP)) on longitudinal profiles of neurocognition in a cohort of 143 people with HIV (PWH) on antiretroviral therapy. Global neurocognition, processing speed, motor skills, and attention/working memory all worsened as CRP increased but only among PWH who, on average, exhibited moderate to severe depressive symptoms (BDI-II > 22). Findings suggest that some PWH with chronically elevated depressive symptoms may have an inflammatory subtype of depression and a particular vulnerability to neurocognitive changes that may respond to drugs targeting inflammation or its neural sequelae.

Updated demographically adjusted norms for the Brief Visuospatial Memory Test-revised and Hopkins Verbal Learning Test-revised in Spanish-speakers from the U.S.-Mexico border region: The NP-NUMBRS project

OBJECTIVE

We generated demographically adjusted norms for the Brief Visuospatial Memory Test-revised (BVMT-R) and the Hopkins Verbal Learning Test-revised (HVLT-R) for Spanish-speakers from the U.S.-Mexico border region as part of a larger normative project. Methods: Healthy native Spanish-speakers (n = 203; Age: 19-60 years; Education: 0-20 years, 59% women) living in Arizona (n = 63) and California (n = 140) completed the BVMT-R and the HVLT-R as part of the larger Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) project. Raw scores were converted to T-scores utilizing fractional polynomial equations, which considered linear and non-linear effects of demographic variables (age, education, sex). To demonstrate the benefit of employing our population-specific norms, we computed the proportion of our participants whose test performance fell below one standard deviation (T-score < 40) when applying published norms from non-Hispanic English-speakers, compared to the base rate derived from the new normative sample. Results: The resulting demographically adjusted T-scores showed the expected psychometric properties and corrected the misclassification in rates of impairment that were obtained when applying norms based on the English-speaking sample. Unexpectedly, participants in Arizona obtained slightly lower HVLT-R T-scores than those in California. This site effect was not explained by available sociodemographic or language factors. Supplementary formulas were computed adjusting for site in addition to demographics. Conclusions: These updated norms improve accuracy in identification of learning and memory impairment among Spanish-speaking adults living in the U.S.-Mexico border region. It will be important to generate additional data for elders, as the present norms are only applicable to adults age 60 and younger.

Demographically-adjusted norms for the Grooved Pegboard and Finger Tapping tests in Spanish-speaking adults: Results from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project

OBJECTIVE

We developed demographically-corrected norms for Spanish-speakers from the U.S.-Mexico border regions of California and Arizona on two tests of motor skills - the Grooved Pegboard Test (Pegboard) and Finger Tapping Test (Tapping) - as part of a larger normative effort.

METHOD

Participants were native Spanish-speakers from the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project (Pegboard: N = 254; Tapping: N = 183; age: 19-60 years; education: 0-20 years; 59% women). We examined the association of demographics (age, education and gender) with raw scores. Raw test scores were then converted to demographically-corrected T-scores via fractional polynomial equations. We also examined rates of impairment (T-score < 40) based on the current norms and on previously published norms for English-speaking non-Hispanic Whites and Blacks.

RESULTS

Having more years of education was associated with better raw test score performance on both tests (p < .001), and increased age was associated with worse performance on Pegboard (p < .001). Men outperformed women on Tapping, and older age was associated with lower raw scores in men only on the Tapping non-dominant hand trial (p = .02). The normed T-scores were confirmed to be normally distributed and free from demographic influences, and resulted in expected rates of impairment. Applying existing norms for English-speaking non-Hispanic Whites and Blacks to the raw scores of Spanish-speakers generally yielded lower than expected impairment rates (2-13%), with one exception: non-dominant Pegboard, for which non-Hispanic White norms overestimated impairment (23%).

CONCLUSIONS

Present findings underscore the importance of appropriate, population-specific normative data, even for tests of motor ability.

Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project: Methodology and sample characteristics

OBJECTIVE

The present paper describes the methodology and sample characteristics of the Neuropsychological Norms for the U.S.-Mexico Border Region in Spanish (NP-NUMBRS) Project, which aimed to generate demographically-adjusted norms for a battery of neuropsychological tests in this population.

METHODS

The sample consisted of 254 healthy Spanish-speakers, ages 19-60 years, recruited from the U.S.-Mexico border regions of Arizona (n = 102) and California (n = 152). Participants completed a comprehensive neuropsychological test battery assessing multiple domains (verbal fluency, speed of information processing, attention/working memory, executive function, learning and memory, visual-spatial skills and fine motor skills). Fluency in both Spanish and English was assessed with performance-based measures. Other culturally-relevant data on educational, social, and language background were obtained via self-report. Demographic influences on test performances were modeled using fractional polynomial equations that allow consideration of linear and non-linear effects.

RESULTS

There were no significant demographic differences between participants tested in Arizona and California. Age and gender were similar across education ranges. Two thirds of the sample were Spanish dominant and the remainder were considered bilingual. Individual articles in this Special Issue detail the generation of demographically adjusted T-scores for the various tests in the battery as well as an exploration of bilingualism effects.

DISCUSSION

Norms developed through the NP-NUMBRS project stand to improve the diagnostic accuracy of neuropsychological assessment in Spanish-speaking young-to-middle-aged adults living in the U.S.-Mexico border region. Application of the present norms to other groups should be done with caution.

Neurocognitive impairment in Spanish-speaking Latinos living with HIV in the US: Application of the neuropsychological norms for the US-Mexico border region in Spanish (NP-NUMBRS)

Objective Latinos in the US are at increased risk for HIV-associated neurocognitive impairment (NCI). Most studies of US Latinos living with HIV have included primarily English-speakers only. We investigated the rate, pattern, and correlates of HIV-associated NCI in native Spanish-speaking Latinos living in the US near the Mexican border. Methods Participants included 407 native Spanish-speaking Latinos (Age: M = 37.65, SD = 10.0; Education: M = 10.75, SD = 4.1; 53% male): 153 persons living with HIV (PLWH; 56% AIDS) and 254 healthy controls. All participants completed comprehensive neuropsychological assessments in Spanish. Raw neuropsychological test scores from seven domains were converted to demographically-adjusted T-scores using norms developed with healthy controls. Global and domain NCI were defined per established criteria. Among PLWH we applied norms developed for non-Hispanic (NH) Whites and Blacks, and investigated correlates of global NCI, including HIV disease characteristics and psychiatric comorbidities. Results Utilizing population specific norms, rates of global NCI were significantly higher among PLWH (39%) than healthy controls (17%), comparable to previously published rates. In contrast, rates of global NCI in the same group of PLWH were significantly different when NH White norms (63%, p < 0.0001) and NH Black norms were used (18%, p < 0.0001). Among PLWH without a history of lifetime substance use disorder, more years of antiretroviral exposure were significantly associated with decreased rates of global NCI. Conclusions Present findings lend support to the validity of newly developed norms for native Spanish-speakers living near the US-Mexico border, and underscore the importance of utilizing appropriate norms to accurately identify HIV-associated NCI.

Apathy is associated with poorer abstinence self-efficacy in individuals with methamphetamine dependence

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Used an apathy composite T-score approach validated in methamphetamine-dependence.

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Apathy, above other factors, associated with poorer drug abstinence self-efficacy.

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Methamphetamine use characteristics unrelated to drug abstinence self-efficacy.

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Social peer pressure was riskiest situation for potential methamphetamine relapse.

Background

Confidence in one’s ability to achieve and maintain drug abstinence (i.e., abstinence self-efficacy) is a strong predictor of substance use treatment outcomes. Neurobehavioral factors that may interfere with abstinence self-efficacy are less well established, particularly in methamphetamine (METH). This study investigated whether apathy, which is highly prevalent during active METH use and periods of abstinence, influences abstinence self-efficacy among METH dependent individuals.

Methods

Sixty-six participants with lifetime METH dependence and METH abuse/METH dependence diagnoses within the last 18 months (mean age [SD] = 39.5 years [10.7]), and no severe psychiatric or neurological diseases, completed the Methamphetamine Self-Efficacy Scale (MSES), alongside a comprehensive neurobehavioral evaluation. The MSES presents six situations that may lead to relapse and collects self-report ratings for two subscales: “Confidence” (i.e., confidence in one’s ability to abstain from using METH, or METH abstinence self-efficacy) and “Temptation” (i.e., how tempted one is to use METH) with regard to each situation. Apathy was measured using a composite T-score comprised of items and scales from three well-validated, self-report assessments.

Results

Multivariable linear regression found that higher Apathy T-scores were significantly associated with lower Confidence ratings (i.e., poorer METH abstinence self-efficacy; p < .05), independent of potentially relevant factors (e.g., Temptation to use METH, comorbid HIV disease, and neurocognitive impairment).

Conclusions

Elevated apathy may adversely impact one’s confidence to abstain from METH use. Findings highlight the importance of addressing apathy in order to improve METH abstinence self-efficacy, which may subsequently increase the likelihood of successful METH treatment outcomes.

Measurement of Cognition for the National Children's Study

The National Children's Study Cognitive Health Domain Team developed detailed plans for assessing cognition longitudinally from infancy to early adulthood. These plans identify high-priority aspects of cognition that can be measured efficiently and effectively, and we believe they can serve as a model for future large-scale longitudinal research. For infancy and toddlerhood, we proposed several paradigms that collectively allowed us to assess six broad cognitive constructs: (1) executive function skills, (2) episodic memory, (3) language, (4) processing speed, (5) spatial and numerical processing, and (6) social cognition. In some cases, different trial sequences within a paradigm allow for the simultaneous assessment of multiple cognitive skills (e.g., executive function skills and processing speed). We define each construct, summarize its significance for understanding developmental outcomes, discuss the feasibility of its assessment throughout development, and present our plan for measuring specific skills at different ages. Given the need for well-validated, direct behavioral measures of cognition that can be used in large-scale longitudinal studies, especially from birth to age 3 years, we also initiated three projects focused on the development of new measures.

Sex Differences in the Patterns and Predictors of Cognitive Function in HIV

Despite advancements in antiretroviral therapy, mild cognitive deficits persist in nearly half of people with HIV (PWH). The profile of impairment in HIV is highly variable with deficits observed in a range of cognitive domains. Despite evidence of greater cognitive impairment among women with HIV (WWH) vs. men with HIV (MWH), it is unclear how MWH and WWH differ in the type of cognitive impairment and in risk factors associated with cognitive impairment profiles. In a large and well-characterized sample of PWH, we used machine learning to identify profiles of cognitive functioning and their associated factors overall and within sex. Participants included 1,666 PWH (201 WWH; 1,465 MMH) from the HIV Neurobehavioral Research Program who completed a neuropsychological test battery at their baseline visits. Using demographically-adjusted T-scores from 13 test outcomes assessing motor skills, executive functioning, attention/working memory, episodic learning and memory, verbal fluency, and processing speed, we used Kohonen self-organizing maps to identify patterns of high-dimensional data by mapping participants to similar nodes based on T-scores (MCLUST R package). Random forest models were used to determine how sociodemographic (e.g., age, education), clinical (e.g., depressive symptoms, substance use disorder), and biological (e.g., HIV disease characteristics) factors differentially related to membership within a cognitive profile. All analyses were repeated within sex. Three cognitive profiles were identified overall and within each sex. Overall and within MWH, there were unimpaired and global weakness profiles. The third profile in the total sample demonstrated relatively weak auditory attention whereas in MWH showed relative strengths in attention and processing speed. Conversely, there was no unimpaired profile among WWH. Rather, WWH demonstrated separate profiles reflecting weakness in motor skills, a relative weakness in learning and delayed recall, and global weaknesses with spared recognition memory. Despite different cognitive profiles by sex, the most discriminative factors were similar between men and women and included reading level (cognitive reserve), current and nadir CD4 count, plasma HIV viral load, duration of HIV disease, age, depressive symptoms, and race/ethnicity. Findings fill a knowledge gap concerning sex differences in cognitive impairment in PWH and inform personalized risk reduction and therapeutic strategies.

Nucleic acid oxidation is associated with biomarkers of neurodegeneration in CSF in people with HIV

OBJECTIVE

To determine whether oxidative stress in virologically suppressed people with HIV (PWH) may contribute to or result from neurodegeneration, we measured 7,8-dihydro-8-oxoguanine (8-oxo-dG), a marker of DNA damage due to oxidative stress, and markers of age-related neurodegeneration, specifically, reduced levels of CSF Aβ-42, and elevated CSF total tau and neurofilament light (NFL).

METHODS

This cross-sectional study prospectively enrolled participants at 6 US centers in the CNS HIV Antiretroviral Effects Research study. Inclusion criteria included HIV+ with a plasma level of HIV RNA ≤50 copies/mL. Exclusions included significant CNS confounding conditions. Measurements of total tau and Aβ-42 were performed by bead suspension array. NFL and 8-oxo-dG were measured using ELISA.

RESULTS

Participants were 53 PWH, mean age 55 (±9.3) years, 19% women, and 48% non-Hispanic White. Higher 8-oxo-dG correlated with markers of AD-related neurodegeneration including lower CSF Aβ-42 (r = -0.34; p = 0.012) and higher CSF NFL (r = 0.39; p = 0.0091) and total tau (r = 0.6696; p < 0.0001). Relationships remained after adjusting for demographic variables. Levels of protein carbonyls, a marker of protein oxidation, were not related to neurodegeneration markers.

CONCLUSIONS

Among virologically suppressed PWH, nucleic acid oxidation was associated with standard CSF biomarkers of neurodegeneration. Potential sources of oxidative stress in PWH include low-level HIV replication, inflammation, mitochondrial dysfunction, and specific antiretroviral drugs. Results suggest that the higher levels of oxidative stress among PWH may play a role in neurodegeneration.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that among virologically suppressed PWH, nucleic acid oxidation is associated with standard CSF biomarkers of neurodegeneration.

Smartphone-Based Measurement of Executive Function in Older Adults with and without HIV

OBJECTIVE

To examine feasibility, convergent validity and biases associated with a mobile color-word interference test (mCWIT) among older persons living with HIV (PLHIV).

METHOD

Over a 14-day period, 58 PLHIV and 32 HIV-uninfected individuals (aged 50-74) completed the mCWIT on smartphones once per day in real-world settings. Participants also completed a comprehensive laboratory-based neuropsychological evaluation.

RESULTS

A high rate of compliance was observed (86%) in the repeated administration of the mCWIT. A practice effect was observed in the overall sample concerning mCWIT subscores, and these learning effects were greater for PLHIV. Stabilization of performance was observed after 6 (HIV+) and 7 days (HIV-) for completion time and after 2 (HIV-) and 3 days (HIV+) for mCWIT errors. A minor fatigue effect was observed in the overall sample which was unassociated with group status. Moderate to strong correlations were found between mCWIT completion time and mCWIT errors with global neurocognition and with all of the individual neurocognitive domains. The strongest associations were with mCWIT completion time and laboratory-based global neurocognition, executive function, and working memory scores.

CONCLUSIONS

Cognitive testing administered within the context of a person's daily life provides qualitatively different data than neuropsychological testing completed in clinical settings, and it may constitute a more ecologically valid indicator of cognitive performance than traditional methods. Mobile cognitive testing has potential to help characterize real-time cognitive performance and serve as a complementary assessment tool to traditional methods.

Lower CSF homovanillic acid relates to higher burden of neuroinflammation and depression in people with HIV disease

BACKGROUND

HIV-related neuroinflammation has been proposed as a catalyst for dopaminergic dysregulation in mesocortical pathways, which may contribute to the pathogenesis of depression. Abnormalities in dopaminergic neurotransmission and depression are common in people with HIV (PWH), however the link between dopamine (DA) and depression in PWH is poorly characterized. This study investigated CSF dopaminergic biomarkers, specifically DA and its metabolite, homovanillic acid (HVA), and examined their relationship with depressive symptoms and CSF neuroinflammatory markers in PWH and HIV-seronegative (HIV-) individuals.

METHODS

Participants were 102 HIV- individuals and 123 PWH (mean age = 42) who underwent neuropsychiatric evaluations and lumbar puncture. Current depression severity was classified using the Beck Depression Inventory-II (BDI-II). CSF was assayed for DA and HVA using high performance liquid chromatography and neuroinflammatory markers using immunoassays. Linear regressions modelled BDI-II scores as a function of HIV, dopaminergic biomarker z-scores, and their interaction, controlling for psychosocial factors. Correlational analyses examined dopaminergic and neuroinflammatory relationships.

RESULTS

PWH had significantly higher BDI-II scores than HIV- participants. DA and HVA were not associated with HIV status but both significantly moderated the effect of HIV on BDI-II scores, such that PWH exhibited higher depressive symptoms than HIV- participants only at lower concentrations of HVA (z ≤ 0.06) and DA (z ≤ 0.11). In PWH only, lower HVA significantly correlated with higher BDI-II scores and higher neuroinflammation, including higher MCP-1 and IP-10.

CONCLUSIONS

Results suggest that the pathophysiology of depression in PWH differs from that in HIV- individuals. Specifically, lower central dopaminergic activity was selectively associated with greater depressive symptoms and neuroinflammation in PWH. With the rise in consideration of DA agonists for the treatment of depression, these results suggest that PWH may show a greater response to these agents than their HIV- peers.

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.

Cerebrospinal Fluid Norepinephrine and Neurocognition in HIV and Methamphetamine Dependence

OBJECTIVE

HIV disease and methamphetamine (METH) dependence share overlapping mechanisms of neurotoxicity that preferentially compromise monoamine-rich frontostriatal circuitry. However, norepinephrine (NE) function is poorly understood in HIV and METH dependence. We evaluated associations between cerebrospinal fluid (CSF) NE and HIV, METH dependence, and neurocognition.

METHODS

Participants included 125 adults, stratified by HIV serostatus (HIV+/HIV-) and recent METH dependence (METH+/METH-), who underwent comprehensive neurocognitive testing and lumbar puncture. CSF NE was assayed using high-performance liquid chromatography. Multivariable regression modelled NE as a function of HIV, METH, and their interaction, adjusting for demographic and clinical factors. Pearson correlations examined relationships between NE and demographically-adjusted neurocognitive domain scores.

RESULTS

HIV significantly interacted with METH (P < 0.001) such that compared with HIV-/METH-, CSF NE was markedly elevated in the single risk-groups (HIV+/METH-: d = 0.96; HIV-/METH+: d = 0.79) and modestly elevated in the dual-risk group (HIV+/METH+: d = 0.48). This interaction remained significant after adjustment for lifetime depression, antidepressant use, and race/ethnicity. In the full sample, higher NE levels significantly correlated with worse global function (r = -0.19), learning (r = -0.23), and delayed recall (r = -0.18). Similar relationships between higher NE and worse neurocognition were detected in the METH- groups (ie, HIV-/METH- and HIV+/METH-) and in the virally-suppressed persons HIV+ subgroup, but not in the METH+ groups (ie, HIV-/METH+, HIV+/METH+).

DISCUSSION

HIV and METH independently, but not additively, relate to noradrenergic excess in the central nervous system, and perturbations to noradrenergic function may represent a pathophysiological mechanism of HIV-related neurocognitive dysfunction. Consistent with prior reports that noradrenergic excess compromises hippocampal and prefrontal function, higher NE related to worse neurocognition, even among successfully treated persons with HIV. Pharmacological and psychosocial interventions that stabilize NE function may improve neurocognition in persons with HIV.

Daily Activities Related to Mobile Cognitive Performance in Middle-Aged and Older Adults: An Ecological Momentary Cognitive Assessment Study

Background

Daily activities have been associated with neurocognitive performance. However, much of this research has used in-person neuropsychological testing that requires participants to travel to a laboratory or clinic, which may not always be feasible and does not allow for the examination of real-time relationships between cognition and behavior. Thus, there is a need to understand the real-time relationship between activities in the real world and neurocognitive functioning to improve tracking of symptoms or disease states and aid in the early identification of neurocognitive deficits among at-risk individuals.

Objective

We used a smartphone-based ecological momentary cognitive assessment (EMCA) platform to examine real-time relationships between daily activities and neurocognitive performance (executive functioning and verbal learning) in the everyday environment of middle-aged and older adults with and without HIV.

Methods

A total of 103 adults aged 50-74 years (67 persons with HIV; mean age 59 years, SD 6.4) were recruited from the University of California, San Diego HIV Neurobehavioral Research Program and the San Diego community. Participants completed our EMCA protocol for 14 days. Participants reported their current daily activities 4 times per day; following 2 of the 4 daily ecological momentary assessment (EMA) surveys, participants were administered the mobile Color-Word Interference Test (mCWIT) and mobile Verbal Learning Test (mVLT), each once per day. Activities were categorized into cognitively stimulating activities, passive leisure activities, and instrumental activities of daily living (IADLs). We used multilevel modeling to examine the same-survey and lagged within-person and between-person effects of each activity type on mobile cognitive performance.

Results

On average, participants completed 91% of the EMA surveys, 85% of the mCWIT trials, and 80% of the mVLT trials, and they reported engaging in cognitively stimulating activities on 17% of surveys, passive leisure activities on 33% of surveys, and IADLs on 20% of surveys. Adherence and activity percentages did not differ by HIV status. Within-persons, engagement in cognitively stimulating activities was associated with better mCWIT performance (β=−1.12; P=.007), whereas engagement in passive leisure activities was associated with worse mCWIT performance (β=.94; P=.005). There were no lagged associations. At the aggregate between-person level, a greater percentage of time spent in cognitively stimulating activities was associated with better mean mVLT performance (β=.07; P=.02), whereas a greater percentage of time spent in passive leisure activities was associated with worse mean mVLT performance (β=−.07; P=.01). IADLs were not associated with mCWIT or mVLT performance.

Conclusions

Smartphones present unique opportunities for assessing neurocognitive performance and behavior in middle-aged and older adults’ own environment. Measurement of cognition and daily functioning outside of clinical settings may generate novel insights on the dynamic association of daily behaviors and neurocognitive performance and may add new dimensions to understanding the complexity of human behavior.

Effects of HIV infection, antiretroviral therapy, and immune status on the speed of information processing and complex motor functions in adult Cameroonians

HIV-associated neurocognitive deficits include impaired speed-of-information processing (SIP) and motor functions. There is lack of Cameroonian adult norms for assessing SIP or motor functions. This study of 683 Cameroonians (320 HIV+, 363 HIV-) establishes demographically-adjusted norms for six SIP [Wechsler-Adult-Intelligence-Scale (WAIS)-III Digit Symbol (WAIS-IIIDS) and Symbol Search (WAIS-IIISS), Stroop Color-Naming, Stroop Word-Reading, Trail-Making Test-A (TMT-A), Color Trails-1 (CTT1)], and two motor function [Grooved Pegboard-dominant (GP-DH) and non-dominant (GP-NDH) hands] tests. We assessed viral effects on SIP and motor functions. HIV-infected persons had significantly lower (worse) T scores on GP-DH, WAIS-IIIDS, Stroop Word-Reading, TMT-A; lower motor and SIP summary T scores. Significantly higher proportion of cases (20.7%) than controls (10.3%) had impaired SIP. Male cases had better T scores than female cases on GP-NDH, WAIS-IIIDS, WAIS-IIISS, TMT-A, CTT1; better SIP summary T scores. Antiretroviral therapy (ART) was associated with significantly better T scores on GP-NDH, WAIS-IIIDS, Stroop Color-Naming; better motor and SIP summary T scores. Cases with higher CD4 had better T scores on WAIS-IIIDS, TMT-A, CTT1; better SIP summary T scores. Overall, we demonstrate that HIV infection in Cameroon is associated with deficits in SIP and motor functions; ART and higher CD4 are associated with better cognitive performance. We provide SIP and psychomotor functions normative standards, which will be useful for neurobehavioral studies in Cameroon of diseases affecting the brain.