The semantic relatedness of cue-intention pairings influences event-based prospective memory failures in older adults with HIV infection

An evaluation of the moderating effects of routine and busyness on the relationship between prospective memory and everyday functioning in older persons with HIV disease

INTRODUCTION

People living with HIV (PLWH) often experience difficulties in everyday functioning, which can arise in part from deficits in the strategic/executive aspects of prospective memory (PM). Using Suchy's Contextually Valid Executive Assessment (ConVExA) framework, this study sought to determine whether the contextual factors of busyness and routine moderate the relationship between the strategic/executive aspects of PM and everyday functioning in older PLWH.

METHODS

Participants in this cross-sectional analysis were 145 PLWH aged 50 years and older who had completed the Martin and Park Environmental Demands (MPED) questionnaire of routine and busyness, the performance-based Cambridge Test of Prospective Memory, and self-report measures of activities of daily living (ADLs) and cognitive symptoms in daily life.

RESULTS

Multiple regression analyses covarying for relevant comorbidities showed that higher levels of busyness - but not routine - were associated with more frequent cognitive symptoms in daily life. Neither busyness nor routine interacted with PM in association with cognitive symptoms. However, routine and a strategic/executive measure of PM interacted in predicting ADLs; specifically, the association between time-based PM and ADLs was stronger in persons with higher levels of routine in their daily lives. Parallel analyses with less executively-demanding event-based PM were null and small.

CONCLUSIONS

Overall, findings provided mixed - and unexpected - evidence for the associations between contextual factors (i.e. routine and busyness), everyday functioning, and PM in this sample of older adults with HIV disease. Results and clinical implications are interpreted and discussed in the framework of the ConVExA model.

Implications of vascular depression for successful cognitive aging in HIV Disease

Although older adults with HIV are at high risk for mild neurocognitive disorders, a subset experience successful cognitive aging (SCA). HIV is associated with an increased risk of vascular depression (VasDep), which can affect cognitive and daily functioning. The current study examined whether VasDep impedes SCA among older adults with HIV. 136 persons with HIV aged 50 years and older were classified as either SCA+ (n = 37) or SCA- (n = 99) based on a battery of demographically adjusted neurocognitive tests and self-reported cognitive symptoms. Participants were also stratified on the presence of vascular disease (e.g., hypertension) and current depression as determined by the Composite International Diagnostic Interview and the Depression/Dejection scale of the Profile of Mood States. A Cochran-Armitage test revealed a significant additive effect of vascular disease and depression on SCA in this sample of older adults with HIV (z = 4.13, p <.0001). Individuals with VasDep had the lowest frequency of SCA+ (0%), which differed significantly from the group with only vascular disease (30%, OR = 0.04, CI = 0.002,0.68)) and the group with neither vascular disease nor depression (47% OR = 0.02, CI = 0.33,0.001). Findings were not confounded by demographics, HIV disease severity, or other psychiatric and medical factors (ps > 0.05). These data suggest that presence of VasDep may be a barrier to SCA in older adults with HIV disease. Prospective, longitudinal studies with neuroimaging-based operationalizations of VasDep are needed to further clarify this risk factor's role in the maintenance of cognitive and brain health in persons with HIV disease.

Lower prospective memory is associated with higher neurocognitive dispersion in two samples of people with HIV: A conceptual replication study

OBJECTIVES

People living with HIV (PLWH) often experience deficits in the strategic/executive aspects of prospective memory (PM) that can interfere with instrumental activities of daily living. This study used a conceptual replication design to determine whether cognitive intraindividual variability, as measured by dispersion (IIV-dispersion), contributes to PM performance and symptoms among PLWH.

METHODS

Study 1 included 367 PLWH who completed a comprehensive clinical neuropsychological test battery, the Memory for Intentions Test (MIsT), and the Prospective and Retrospective Memory Questionnaire (PRMQ). Study 2 included 79 older PLWH who completed the Cogstate cognitive battery, the Cambridge Prospective Memory Test (CAMPROMPT), an experimental measure of time-based PM, and the PRMQ. In both studies, a mean-adjusted coefficient of variation was derived to measure IIV-dispersion using normative T-scores from the cognitive battery.

RESULTS

Higher IIV-dispersion was significantly associated with lower time-based PM performance at small-to-medium effect sizes in both studies (mean r s  = -0.30). The relationship between IIV-dispersion and event-based PM performance was comparably small in magnitude in both studies (r s  = -0.19, -0.20), but it was only statistically significant in Study 1. IIV-dispersion showed very small, nonsignificant relationships with self-reported PM symptoms in both samples (r s < 0.10).

CONCLUSIONS

Extending prior work in healthy adults, these findings suggest that variability in performance across a cognitive battery contributes to laboratory-based PM accuracy, but not perceived PM symptoms, among PLWH. Future studies might examine whether daily fluctuations in cognition or other aspects of IIV (e.g., inconsistency) play a role in PM failures in everyday life.

Subjective cognitive decline disrupts aspects of prospective memory in older adults with HIV disease

Subjective cognitive decline (SCD) is a risk factor for dementia that may occur at higher rates in people with HIV (PWH). Prospective memory (PM) is an aspect of cognition that may help us better understand how SCD impacts daily life. Paricipants were 62 PWH aged ≥ 50 years and 33 seronegative individuals. SCD was operationalized as normatively elevated cognitive symptoms on standardized questionnaires, but with normatively unimpaired performance-based cognition and no current affective disorders. PM was measured with the Comprehensive Assessment of Prospective Memory (CAPM), the Cambridge Test of Prospective Memory (CAMPROMPT), and an experimental computerized time-based PM task. A logistic regression revealed that older PWH had a three-fold increased likelihood for SCD. Among the PWH, SCD was associated with more frequent PM symptoms and poorer accuracy on the time-based scale of the CAMPROMPT. These findings suggest that SCD disrupts PM in older PWH.

Factor Structure of the Memory for Intentions Test (MIsT): A Conceptual Replication in Older Adults and People with HIV Disease

OBJECTIVE

The Memory for Intentions Test (MIsT) is a clinical measure of prospective memory that has strong evidence for convergent, discriminative, and ecological validity. This study uses a conceptual replication design to evaluate the latent structure of the MIsT in two parallel samples who commonly experience prospective memory deficits: older adults and people living with HIV disease.

PARTICIPANTS AND METHODS

Study participants included 303 people with HIV disease (ages 18-67) and 267 community-dwelling older adults (ages 50-91). Confirmatory factor analyses of the MIsT were conducted separately in each sample. We evaluated a one-factor model, as well as three two-factor models with the MIsT items loading onto each factor based on cue type, delay interval, or response modality.

RESULTS

The one-factor model provided the best (and most parsimonious) fit to the data in both study samples. All two-factor models also demonstrated good fit statistics, although correlations between the two factors in each model were high and none of the two-factor models provided a significantly better fit than the one-factor model.

CONCLUSIONS

Results of this conceptual replication study provide support for a robust factor structure of the MIsT across older adults and people with HIV disease. A total score for the MIsT provides the most parsimonious solution, although available evidence and theory also support the potential use of subscales (e.g., cue type). Future studies of the MIsT would be useful to determine its psychometrics in different clinical populations and across demographic factors (e.g., race/ethnicity).

Enhancing cue salience improves aspects of naturalistic time-based prospective memory in older adults with HIV disease

OBJECTIVE

Older persons living with HIV (PLWH) disease commonly experience failures of time-based prospective memory (PM) in their daily lives. This study examined the benefits of providing strategic supports at encoding, monitoring, and cue detection for naturalistic time-based PM among older PLWH.

METHOD

Participants included 116 older PLWH and 48 seronegatives who completed a baseline neuropsychological evaluation (see Woods et al., 2020), including a laboratory PM experiment that paralleled the design of the current naturalistic study. The naturalistic time-based PM task required participants to press a button on a portable PM response box 4 times per day for 1 month. PLWH were randomly assigned to an unsupported control condition or to an experimental group in which strategic processing was supported at encoding (implementation intentions and visualization), monitoring (content-free cuing), and/or cue detection (auditory alarm). The seronegative participants were all assigned to the unsupported control group.

RESULTS

In a model adjusting for age and affective disorders, PLWH who received all three supports in combination demonstrated moderately better naturalistic time-based PM accuracy as compared with PLWH controls. Both the cue detection and combination conditions were associated with markedly more precise response timing on the naturalistic time-based PM task. Supported PM accuracy as measured in the laboratory was positively associated with naturalistic PM accuracy among PLWH in the experimental groups.

CONCLUSIONS

Providing strategic supports to enhance the cue salience of naturalistic time-based PM tasks may improve both the accuracy and timing with which older PLWH remember to perform time-based intentions. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Psychometrics and Validity of the Survey of Memory-Related Quality of Life in HIV Disease

OBJECTIVE

Retrospective and prospective memory deficits are associated with lower quality of life (QoL); however, there are no validated measures that comprehensively and directly assess the impact of memory problems on QoL. The Survey of Memory-Related Quality of Life (SMRQoL) was developed as a 30-item questionnaire to measure memory-related QoL.

METHOD

Both HIV+ (n = 195) and HIV- (n = 146) participants completed the SMRQoL, a neurocognitive research battery, and validated self-report questionnaires of memory, QoL, and mood. Participants were recruited into younger (age ≤ 40 years) and older (age ≥ 50 years) groups per the parent study design.

RESULTS

The SMRQoL had a unidimensional factor structure and demonstrated measurement invariance across the HIV+ and HIV- participants. Analyses of 111 clinically stable participants (e.g., persons with no incident or remitting central nervous system disorders) who returned for a 14-month follow-up visit indicated that the SMRQoL had adequate test-retest stability. There was a significant interaction of age and HIV status on the SMRQoL, such that older HIV+ participants reported the lowest memory-related QoL. SMRQoL scores were associated with validated measures of mental and physical QoL, self-reported memory and cognitive symptoms, and performance-based memory and executive functions.

CONCLUSIONS

The SMRQoL shows evidence of reliability and validity as a measure of memory-related QoL that can be used to assess the impact of memory problems on everyday life, but future work is needed to demonstrate the measure's incremental value in the context of diagnosis and treatment.

A Clinical Pilot Study of Spaced Retrieval Practice with a Self-Generation Booster to Improve Health-Related Memory in Persons With HIV Disease

Objective

Spaced retrieval practice (SRP) and self-generation are among the most replicated and effective mnemonic strategies in the cognitive psychology literature, but their benefits have not yet been realized in healthcare settings. This study used a randomized, between-subjects design to examine the hypothesis that SRP with a self-generation booster can improve memory for health-related information among clinically referred persons with HIV (PWH), who often have difficulty acquiring new health knowledge.

Method

A consecutive series of 41 PWH referred to a county-funded urban neuropsychology clinic were enrolled. Participants were randomly assigned to learn four statements about the treatment of a mock infectious disease in either a massed study control condition (n = 20) or an SRP condition (n = 21) in which they received two distributed free recall training tests supplemented with self-generation for missed items. The primary outcome was participants’ free recall of the four treatment statements after a 20-minute delay filled with nonverbal tests.

Results

PWH participants in the SRP condition were four times more likely than controls to recall at least one treatment statement at the 20-minute delay. SRP was not related to post-test recognition or health-related decision-making performance but was associated with moderately better self-efficacy for decision-making.

Conclusions

Findings from this pilot study show the potential of SRP with a self-generation booster to improve learning and memory for health-related information among PWH in clinic.

Online pharmacy navigation skills are associated with prospective memory in HIV disease

OBJECTIVE

The increased use of online pharmacy services in the midst of the COVID-19 pandemic provides an important backdrop against which to examine the role of neurocognitive functions in health-related Internet navigation skills among persons with chronic medical conditions, such as HIV disease. Prospective memory (PM) is reliably impaired in HIV disease and is related to laboratory-based measures of medication management capacity in other populations. This study examined whether PM shows veridicality in relationship to online pharmacy navigation skills in persons with HIV disease.

METHOD

Participants included 98 persons with HIV disease age 50 and older who completed the Cambridge Prospective Memory Test (CAMPROMPT) and the Medication-Management Test-Revised (MMT-R) as part of a neuropsychological study. Participants also completed the Test of Online Pharmacy Skills (TOPS), which required them to navigate a simulated, experimenter-controlled online pharmacy to perform several naturalistic tasks (e.g., refill an existing prescription).

RESULTS

Lower PM had medium associations with poorer MMT-R and TOPS accuracy scores that were not better explained by other neurocognitive functions. The association between PM and TOPS accuracy was driven by errors of omission and did not vary meaningfully based on whether the intention was cued by time or an event.

CONCLUSIONS

These data suggest that PM cue detection processes show veridicality with online pharmacy navigation skills. Future studies might examine the benefits of PM-based strategies (e.g., salient prompts) in supporting online health navigation skills in populations that experience clinically impactful PM failures.

Mindfulness-based stress reduction for HIV-associated neurocognitive disorder: Rationale and protocol for a randomized controlled trial in older adults

The symptom burden of HIV-associated neurocognitive disorder (HAND) is high among older individuals, and treatment options are limited. Mindfulness-based stress reduction (MBSR) has potential to improve neurocognitive performance, psychosocial wellbeing, and quality of life, but empirical studies in this growing vulnerable population are lacking. In this trial, participants (N = 180) age 55 and older who are living with HIV infection, are on combination antiretroviral therapy with suppressed viral loads, and yet continue to experience behavioral and cognitive symptoms of HAND, are randomized to MBSR or to a waitlist control arm that receives MBSR following a 16-week period of standard care. Primary outcomes (attention, executive function, stress, anxiety, depression, everyday functioning, quality of life) and potential mediators (affect, mindfulness) and moderators (social support, loneliness) are assessed at baseline and weeks 8, 16, and 48 in both groups, with an additional assessment at week 24 (post-MBSR) in the crossover control group. Assessments include self-report and objective measures (e.g., neuropsychological assessment, neurological exam, clinical labs). In addition, a subset of participants (n = 30 per group) are randomly selected to undergo fMRI to evaluate changes in functional connectivity networks and their relationship to changes in neuropsychological outcomes. Forthcoming findings from this randomized controlled trial have the potential to contribute to a growing public health need as the number of older adults with HAND is expected to rise.

Prospective memory and spontaneous compensatory mnemonic strategy use in the laboratory and daily life in HIV-associated neurocognitive disorders

INTRODUCTION

Older adults with HIV-associated neurocognitive disorders (HAND) are at high risk for deficits in the resource-demanding, strategic aspects of prospective memory (PM) that can adversely affect health outcomes. This study examined the frequency and correlates of spontaneous compensatory strategy use during a laboratory-based PM task and its associations with the use of mnemonic strategies in daily life.

METHOD

Participants included 53 older adults with HAND, 89 older persons with HIV without HAND, and 62 seronegatives who completed the Cambridge Prospective Memory Test (CAMPROMPT), on which the type, frequency, and quality of their compensatory strategy use was quantified. Participants also completed self-report measures of PM symptoms and the frequency of mnemonic compensatory strategy use in daily life.

RESULT

There were no significant group-level effects on strategy use during the CAMPROMPT. Persons with HAND had moderately lower time-, but not event-based PM scores. Higher compensatory strategy use was strongly associated with better PM, particularly for time-based cues. Moreover, higher compensatory strategy use on the CAMPROMPT was associated with more frequent general mnemonic strategy use in daily life, and specifically with more frequent use of internal PM strategies (e.g., visualization) for medication adherence.

CONCLUSION

Spontaneous compensatory mnemonic strategy use can support PM performance among older adults with HAND in the laboratory. Strategy use in the laboratory may be a marker for the extent to which older adults with HAND use other compensatory strategies to support memory in their daily life. Future studies may examine whether compensatory mnemonic strategies can be taught and used to support PM in the daily lives of older persons with HIV disease.

One-year stability of prospective memory symptoms and performance in aging and HIV disease

Introduction: HIV disease and aging can both affect prospective memory (PM), which describes the complex process of executing delayed intentions and plays an essential role in everyday functioning. The current study investigated the course of PM symptoms and performance over approximately one year in younger and older persons with and without HIV disease. Method: Participants included 77 older (>50 years) and 35 younger (<40 years) HIV+ individuals and 44 older and 27 younger seronegative adults. Participants completed the Memory for Intentions Test to measure PM in the laboratory, the Prospective and Retrospective Memory Questionnaire to measure PM symptoms in daily life, and several clinical measures of executive functions and retrospective memory as a part of a comprehensive neurocognitive evaluation at baseline and at 14-month follow-up. Results: Findings showed additive, independent main effects of HIV and aging on time- and event-based PM performance in the laboratory, but no change in PM over time. There were no interactions between time and HIV or age groups. Parallel findings were observed for clinical measures of retrospective memory and executive functions. Older HIV+ adults endorsed the greatest frequency of PM symptoms, but there was no change in PM symptom severity over time and no interactions between time and HIV or age groups. There were no effects of HIV or aging on naturalistic PM performance longitudinally. Conclusion: Overall these findings suggest that PM symptoms and performance in the laboratory are stably impaired over the course of a year in the setting of aging and HIV disease.

Frequency and Correlates of Subjective Cognitive Impairment in HIV Disease

The increasing prevalence of older adults living with HIV has raised growing concerns about a possible rise in the incidence of neurocognitive disorders due to HIV and other age-related factors. In typical aging, subjective cognitive impairment (SCI) among individuals with normal neurocognitive functioning may be an early manifestation of an incipient neurocognitive disorder. The current study examined the frequency and correlates of SCI in 188 HIV-infected adults without performance-based neurocognitive deficits or a current psychiatric disorder and 133 HIV seronegative comparison participants. All participants completed the Prospective and Retrospective Memory Questionnaire and Profile of Mood States Confusion/Bewilderment scale. Consistent with the diagnostic criteria proposed by Jessen et al. (Alzheimers Dement 10(6):844-852, 2014), participants were classified with SCI if their scores on either of the self-reported measures was greater than 1.5 SD above the normative mean. A logistic regression controlling for current mood complaints and lifetime history of substance use disorders revealed that HIV infection increased the odds of SCI (odds ratio= 4.5 [1.6, 15.4], p = 0.004). Among HIV+ individuals, SCI was associated with lower performance-based learning and delayed memory scores (Cohen's d range 0.41-0.42.) and poorer global everyday functioning (odds ratio= 8.5 [2.6, 15.9]), but not HIV disease severity (ps > 0.10). In a sample of individuals without neurocognitive impairment or elevated mood symptoms, HIV disease was associated with a nearly fivefold increased odds of SCI compared to seronegative individuals, which may indicate an increased risk for developing major neurocognitive disorders as these HIV+ individuals age.

Promoting resilience through neurocognitive functioning in youth living with HIV

Using a phased model of intervention development, we developed an intervention to promote resilience in youth living with HIV via improved neurocognitive resources. First, youth completed a naturalistic prospective memory (PM) task and were randomized into a visualization condition or control condition. Next, 47 of these participants completed another naturalistic PM task and were randomized into Calendaring condition, an Alarm condition, a Combined condition, or a Control condition. Youth with low PM demonstrated observable gains from the visualization technique. Youth in the Combined Calendaring and Alarm condition demonstrated significantly better performance than participants in the Control and Calendaring conditions. In a Proof-of-Concept study with 16 youth, the previous findings were translated into a single session in-person intervention followed by tailored text messaging to improve adherence and viral load via improved neurocognitive resources. The resulting intervention showed a signal of effect with viral load reductions in youth with available data. Targeting compensatory strategies to enhance neurocognitive functioning may promote resilience and health outcomes. A randomized pilot study with a control condition is the next step.

Development and reliability of the Prospective Memory Assessment for Children & Youth (PROMACY): A preliminary study in a nonclinical sample

Prospective memory (PM), "remembering to remember," has been linked to important functional outcomes in adults. Studies of PM in children and adolescents would benefit from the development and validation of developmentally appropriate clinical measures with known psychometric properties. The Prospective Memory Assessment for Children & Youth (PROMACY), a performance-based measure of PM, was developed for the Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol, Memory and Executive Functioning Substudy, and includes Summary, Time-, and Event-based scores derived from eight trials with an ongoing word search task. Fifty-four healthy perinatally HIV-exposed, uninfected children and youth, mean age 13 years, 54% female, 76% Black/non-Hispanic, and 61% impoverished were included in this psychometric analysis. PROMACY Summary Scores demonstrated low, but broadly acceptable internal consistency as measured by Cronbach's alpha and Spearman-Brown. Better PROMACY performance was associated with older age, but no other demographic factors. Generally medium-sized correlations were observed between the PROMACY Summary Score and standard clinical measures of retrospective memory, working memory, executive functions, and IQ. Findings from this preliminary psychometric study of nonclinical children and youth provide cautious support for the internal consistency and construct validity of PROMACY's Summary Score that awaits replication and extension in larger samples of healthy children, youth and clinical populations.

Intraindividual variability in neurocognitive performance is associated with time-based prospective memory in older adults

INTRODUCTION

Older adults demonstrate poorer prospective memory (PM) performance than younger adults, particularly for time-based cues and other strategically demanding PM tasks. Intraindividual variability (IIV) in neurocognitive test performance is an index of cognitive control that may be related to the execution of strategically demanding PM tasks.

METHOD

Participants included 194 older Australian adults (age 50 to 88 years) who completed the Memory for Intentions Screening Test (MIST), the Prospective and Retrospective Memory Questionnaire (PRMQ), and clinical measures of executive functions. A measure of naturalistic time-based PM was also administered, in which participants were asked to call the examiner 24 hours after their appointment to report how many hours they slept. IIV was calculated as the mean-adjusted coefficient of variation (CoV) across subtests of the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS).

RESULTS

IIV was significantly associated with time-based PM in the laboratory, independent of demographics. Additionally, IIV significantly predicted performance on a naturalistic time-based PM trial, independent of demographics and chronic medical conditions. IIV was not related to event-based laboratory PM or self-reported PM symptoms in daily life. Clinical measures of executive functions were similarly associated with time-based PM and the naturalistic PM task, but not with event-based PM or subjective PM symptoms.

CONCLUSIONS

These results indicate that cognitive control, as indexed by IIV in neurocognitive performance, may play a role in naturalistic PM, as well as in highly strategic, but not automatic, laboratory-based PM among older adults.

Calendaring and alarms can improve naturalistic time-based prospective memory for youth infected with HIV

Individuals with HIV disease often evidence deficits in prospective memory (PM), which interfere with daily functioning and increase the risk of suboptimal health behaviours. This study examined the benefits of simple encoding and cueing supports on naturalistic time-based PM in 47 HIV-positive young adults. All participants completed a naturalistic time-based PM task in which they were instructed to text the examiner once per day for seven days at a specified time. Participants were randomised into (1) a Calendaring condition in which they created a calendar event in their mobile telephone for the specified texting time; (2) an Alarm condition in which they programmed an alarm into their mobile telephone for the specified texting time; (3) a Combined calendaring and alarm condition; and (4) a Control condition. Participants in the Combined condition demonstrated significantly better naturalistic PM performance than participants in the Control and Calendaring conditions. Findings indicate that HIV-positive young people may benefit from a combined calendaring and alarm supportive strategy for successful execution of future intentions in daily life.

Aging and Apolipoprotein E in HIV Infection

With the implementation of increasingly effective antiretroviral therapy (ART) over the past three decades, individuals infected with HIV live a much longer life. HIV infection is no longer a terminal but rather a chronic disease. However, the lifespan of infected individuals remains shorter than that of their uninfected peers. Even with ART, HIV infection may potentiate “premature” aging. Organ-associated disease and systemic syndromes that occur in treated HIV-infection are like that of older, uninfected individuals. Brain aging may manifest as structural changes or neurocognitive impairment that are beyond the chronological age. The spectrum of neurological, cognitive, and motor deficiencies, currently described as HIV-associated neurocognitive disorders (HAND), may reflect earlier onset of mechanisms common to HIV infection and aging (accelerated aging). HAND could also reflect the neurological impact of HIV infection superimposed on comorbidities linked to age and chronic inflammation, leading to a higher prevalence of neurocognitive impairment across the age span (accentuated aging). In addition, apolipoprotein E (ApoE), one of the most influential host risk factors for developing Alzheimer’s disease, has been implicated in the development of HAND. But studies differ as to whether ApoE is relevant, and whether age and ApoE interact to impair brain function in the HIV-infected patient. What is clear is that HIV-infected individuals are living longer with HIV, and therefore factors related to aging and health need to be examined in the context of current, effective ART. This review addresses the recent evidence for the influence of aging and ApoE on HIV-associated neurocognitive impairment.

HIV, prospective memory, and cerebrospinal fluid concentrations of quinolinic acid and phosphorylated Tau

There is mounting evidence that prospective memory (PM) is impaired during HIV infection despite treatment. In this prospective study, 66 adults (43 HIV+ and 23 HIV negative) underwent PM assessment and cerebrospinal fluid (CSF) examination. HIV+ participants had significantly lower PM but significantly higher CSF concentrations of CXCL10 and quinolinic acid (QUIN). Higher CSF phosphorylated Tau (pTau) was associated with worse PM. In a secondary analysis excluding outliers, higher QUIN correlated with higher pTau. CSF QUIN is thus elevated during HIV infection despite antiretroviral therapy and could indirectly contribute to impaired PM by influencing the formation of pTau.

Memory Impairment in HIV-Infected Individuals with Early and Late Initiation of Regular Marijuana Use

Marijuana use is disproportionately prevalent among HIV-infected individuals. The strongest neurocognitive effect of marijuana use is impairment in the domain of memory. Memory impairment is also high among HIV-infected persons. The present study examined 69 HIV-infected individuals who were stratified by age of regular marijuana initiation to investigate how marijuana use impacts neurocognitive functioning. A comprehensive battery assessed substance use and neurocognitive functioning. Findings indicated early onset marijuana users (regular use prior to age 18), compared to non-marijuana users and late onset marijuana users (regular use at age 18 or later), were over 8 times more likely to have learning impairment and nearly 4 times more likely to have memory impairment. A similar pattern of early onset marijuana users performing worse in learning emerged when examining domain deficit scores. The potential for early onset of regular marijuana use to exacerbate already high levels of memory impairment among HIV-infected persons has important clinical implications, including increased potential for medication non-adherence and difficulty with independent living.

A systematic review of prospective memory in HIV disease: from the laboratory to daily life

OBJECTIVE

Prospective memory (PM) is described as the capacity to form and maintain an intention that is executed in response to a specific cue. Neural injury and associated neurocognitive disorders are common among persons living with HIV disease, who might therefore be susceptible to impairment in PM.

METHOD

This literature review utilized a structured qualitative approach to summarize and evaluate our current understanding of PM functioning in people living with HIV disease. 33 studies of PM in HIV+ persons met criteria for inclusion.

RESULTS

Findings showed that HIV is associated with moderate deficits in PM, which appear to be largely independent of commonly observed comorbid factors. The pattern of PM deficits reveals dysregulation of strategic processes that is consistent with the frontal systems pathology and associated executive dysfunction that characterizes HIV-associated neural injury. The literature also suggests that HIV-associated PM deficits present a strong risk of concurrent problems in a wide range of health behaviors (e.g. medication non-adherence) and activities of daily living (e.g. employment). Early attempts to improve PM in HIV disease have revealed that supporting strategic processes might be effective for some individuals.

CONCLUSIONS

HIV-associated PM deficits are common and exert a significant adverse effect on the daily lives and health of infected persons. Much work remains to be done to understand the cognitive architecture of HIV-associated PM deficits and the most efficient means to enhance PM functioning and improve health outcomes in persons living with HIV.

Prospective memory in youth with perinatally-acquired HIV infection

Youth with perinatal HIV infection (PHIV) are at increased risk for neurocognitive impairment (NCI). Prospective memory (PM) is a complex neurocognitive function that has been shown to be impaired in adults with HIV disease and independently associated with poorer daily living skills, including medication nonadherence. The current study sought to determine the presence and extent of PM deficits in youth with PHIV. Participants included 173 youth with PHIV and 85 youth perinatally HIV-exposed but uninfected (PHEU), mean age 14.1 years, 75% black, 18% Hispanic. Among youth with PHIV, 26% had a past AIDS-defining condition (Centers for Disease Control and Prevention [CDC], Class C), 74% did not (non-C). Adjusted generalized estimating equation models were used to compare groups (PHIV/C, PHIV/non-C, and PHEU) on the Naturalistic Event-Based Prospective Memory Test (NEPT) and the Prospective Memory Assessment for Children & Youth (PROMACY). Secondarily, subgroups defined by HIV serostatus and global NCI were compared (PHIV/NCI, PHIV/non-NCI, PHEU). PHIV/C had significantly lower NEPT scores than PHEU, with decreases of 40% in mean scores, but did not differ from PHIV/non-C. PHIV/NCI had 11-32% lower PROMACY scores and 33% lower NEPT scores compared to PHIV/non-NCI (all p < .05); significantly, lower scores for PHIV/NCI versus PHEU also were observed for PROMACY and NEPT indices. Findings suggest a subset of youth with PHIV (those with a prior AIDS-defining diagnosis) is vulnerable to PM deficits. The extent to which PM deficits interfere with development and maintenance of independent living and health-related behaviors during transition to adulthood requires further study.

Accelerated and accentuated neurocognitive aging in HIV infection

There is debate as to whether the neurocognitive changes associated with HIV infection represent an acceleration of the typical aging process or more simply reflect a greater accentuated risk for age-related declines. We aimed to determine whether accelerated neurocognitive aging is observable in a sample of older HIV-infected individuals compared to age-matched seronegatives and older old (i.e., aged ≥65) seronegative adults. Participants in a cross-sectional design included 48 HIV-seronegative (O-) and 40 HIV-positive (O+) participants between the ages of 50-65 (mean ages = 55 and 56, respectively) and 40 HIV-seronegative participants aged ≥65 (OO-; mean age = 74) who were comparable for other demographics. All participants were administered a brief neurocognitive battery of attention, episodic memory, speeded executive functions, and confrontation naming (i.e., Boston Naming Test). The O+ group performed more poorly than the O- group (i.e., accentuated aging), but not differently from the OO- on digit span and initial recall of a supraspan word list, consistent with an accelerating aging profile. However, the O+ group's performance was comparable to the O- group on all other neurocognitive tests (ps > 0.05). These data partially support a model of accelerated neurocognitive aging in HIV infection, which was observed in the domain of auditory verbal attention, but not in the areas of memory, language, or speeded executive functions. Future studies should examine whether HIV-infected adults over 65 evidence accelerated aging in downstream neurocognitive domains and subsequent everyday functioning outcomes.

Prospective Memory in Posttraumatic Stress Disorder

OBJECTIVES

Neuropsychological studies of posttraumatic stress disorder (PTSD) have revealed deficits in attention/working memory, processing speed, executive functioning, and retrospective memory. However, little is known about prospective memory (PM) in PTSD, a clinically relevant aspect of episodic memory that supports the encoding and retrieval of intentions for future actions.

METHODS

Here we examined PM performance in 40 veterans with PTSD compared to 38 trauma comparison (TC) veterans who were exposed to combat but did not develop PTSD. All participants were administered the Memory for Intentions Test (MIST; Raskin, Buckheit, & Sherrod, 2010), a standardized and validated measure of PM, alongside a comprehensive neurocognitive battery, structured diagnostic interviews for psychiatric conditions, and behavioral questionnaires.

RESULTS

Veterans with PTSD performed moderately lower than TC on time-based PM, with errors primarily characterized as PM failure errors (i.e., omissions). However, groups did not differ in event-based PM, ongoing task performance, or post-test recognition of PM intentions for each trial. Lower time-based PM performance was specifically related to hyperarousal symptoms of PTSD. Time-based-performance was also associated with neuropsychological measures of retrospective memory and executive functions in the PTSD group. Nevertheless, PTSD was significantly associated with poorer PM above and beyond age and performance in retrospective memory and executive functions.

DISCUSSION

Results provide initial evidence of PM dysfunction in PTSD, especially in strategic monitoring during time-based PM tasks. Findings have potential implications for everyday functioning and health behaviors in persons with PTSD, and deserve replication and future study. (JINS, 2016, 22, 724-734).

Pill Burden Influences the Association Between Time-Based Prospective Memory and Antiretroviral Therapy Adherence in Younger But Not Older HIV-Infected Adults

Prospective memory (PM) is associated with antiretroviral (ARV) adherence in HIV, but little is known about how pill burden and age might affect this association. One hundred seventeen older (≥50 years) and 82 younger (<50 years) HIV-infected adults were administered a measure of PM in the laboratory and subsequently were monitored for ARV adherence for 30 days using the Medication Event Monitoring System. In the older group, better time-based PM performance was associated with higher likelihood of adherence, irrespective of pill burden. Within the younger sample, time-based PM was positively related to adherence only in participants with lower pill burdens. Younger HIV-infected individuals with higher pill burdens may overcome the normal effects of time-based PM on adherence through compensatory medication-taking strategies, whereas suboptimal use of these strategies by younger HIV-infected individuals with lower pill burdens may heighten their risk of ARV nonadherence secondary to deficits in time-based PM.

The effects of HIV disease and older age on laboratory-based, naturalistic, and self-perceived symptoms of prospective memory: does retrieval cue type and delay interval matter?

There is a rising prevalence of older HIV+ adults who are at risk of deficits in higher order neurocognitive functions and associated problems in everyday functioning. The current study applied multiprocess theory to examine the effects of HIV and aging on measures of laboratory-based, naturalistic, and self-perceived symptoms of prospective memory (PM). Participants included 125 Younger (48 with HIV, age = 32 ± 4.6 years) and 189 Older (112 with HIV, age = 56 ± 4.9 years) adults. Controlling for global neurocognitive functioning, mood, and other demographics, older age and HIV had independent effects on long-delay time-based PM in the laboratory, whereas on a naturalistic PM task older HIV- adults performed better than older HIV+ adults and younger persons. In line with the naturalistic findings, older age, but not HIV, was associated with a relative sparing of self-perceived PM failures in daily life across longer delay self-cued intervals. Findings suggest that, even in relatively younger aging cohorts, the effects of HIV and older age on PM can vary across PM delay intervals by the strategic demands of the retrieval cue type, are expressed differently in the laboratory and in daily life, and are independent of other higher order neurocognitive functions (e.g., retrospective memory).

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

BACKGROUND

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

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

The Role of Extrinsic Rewards and Cue-Intention Association in Prospective Memory in Young Children

The current study examined, for the first time, the effect of cue-intention association, as well as the effects of promised extrinsic rewards, on prospective memory in young children, aged 5-years-old (n = 39) and 7-years-old (n = 40). Children were asked to name pictures for a toy mole, whilst also having to remember to respond differently to certain target pictures (prospective memory task). The level to which the target picture was associated with the intention was manipulated across two conditions (low- or high-association) for all participants, whilst half of the participants were promised a reward for good prospective memory performance. Results showed a main effect of age, with the 7-year-olds outperforming the 5-year-olds. Furthermore, there was a main effect of reward, with those promised a reward performing better than those who were not. No effect was found for cue-association, with the participants of both age groups performing equally well in both association conditions. No significant interactions were found between any of the variables. The potentially important role of reward in young children's everyday prospective memory tasks, and possible reasons for the lack of a reflexive-associative effect, are discussed.

Does Older Age Confer an Increased Risk of Incident Neurocognitive Disorders Among Persons Living with HIV Disease?

OBJECTIVE

This study aimed to determine the combined effects of age and HIV infection on the risk of incident neurocognitive disorders.

METHOD

A total of 146 neurocognitively normal participants were enrolled at baseline into one of four groups based on age (≤ 40 years and ≥ 50 years) and HIV serostatus resulting in 24 younger HIV-, 27 younger HIV+, 39 older HIV-, and 56 older HIV+ individuals. All participants were administered a standardized clinical neuropsychological battery at baseline and 14.3 ± .2 months later.

RESULTS

A logistic regression predicting incident neurocognitive disorders from HIV, age group, and their interaction was significant (χ(2)[4] = 13.56, p = .009), with a significant main effect of HIV serostatus (χ(2)[1] = 5.01, p = .025), but no main effect of age or age by HIV interaction (ps > .10). Specifically, 15.7% of the HIV+ individuals had an incident neurocognitive disorder as compared to 3.2% of the HIV- group (odds ratio = 4.8 [1.2, 32.6]). Among older HIV+ adults, lower baseline cognitive reserve, prospective memory, and verbal fluency each predicted incident neurocognitive disorders at follow-up.

CONCLUSIONS

Independent of age, HIV infection confers a nearly fivefold risk for developing a neurocognitive disorder over approximately one year. Individuals with lower cognitive reserve and mild weaknesses in higher-order neurocognitive functions may be targeted for closer clinical monitoring and preventative measures.

SL, Woods SP, Grant I, Jeste DV, Moore DJ. Physical Activity is Associated with Better Neurocognitive and Everyday Functioning Among Older Adults with HIV Disease

We examined the association between physical activity (PA), neurocognitive impairment (NCI), and instrumental activities of daily living (IADLs) among older HIV+ persons. One hundred older HIV+ adults completed the International Physical Activity Questionnaire, a neurocognitive battery, and IADL scale. Higher levels of moderate PA were associated with lower odds of NCI (p = 0.01), even when covariates were modeled. The association between moderate PA and NCI was driven by executive function (p = 0.04). Higher levels of moderate PA were also associated with lower odds of IADL Dependence (p = 0.03), although this fell to a trend (p = 0.08) when including covariates. Follow-up analysis showed those with both NCI and IADL Dependence had lower moderate PA than those with neither (p = 0.03). While these cross-sectional findings suggest PA is associated with better neurocognitive and everyday functioning in older HIV+ adults, longitudinal studies utilizing objective PA methods are needed to evaluate directionality and mechanisms.

Allowing brief delays in responding improves event-based prospective memory for young adults living with HIV disease

Event-based prospective memory (PM) tasks require individuals to remember to perform an action when they encounter a specific cue in the environment, and they have clear relevance for daily functioning for individuals with HIV. In many everyday tasks, not only must the individual maintain the intent to perform the PM task, but the PM task response also competes with the alternative and more habitual task response. The current study examined whether event-based PM can be improved by slowing down the pace of the task environment. Fifty-seven young adults living with HIV performed an ongoing lexical decision task while simultaneously performing a PM task of monitoring for a specific word (which was focal to the ongoing task of making lexical decisions) or syllable contained in a word (which was nonfocal). Participants were instructed to refrain from making task responses until after a tone was presented, which occurred at varying onsets (0-1600 ms) after each stimulus appeared. Improvements in focal and nonfocal PM accuracy were observed with response delays of 600 ms. Furthermore, the difference in PM accuracy between the low-demand focal PM task and the resource-demanding nonfocal PM task was reduced by half across increasingly longer delays, falling from 31% at 0-ms delay to only 14% at 1600-ms delay. The degree of ongoing task response slowing for the PM conditions, relative to a control condition that did not have a PM task and made lexical decisions only, also decreased with increased delay. Overall, the evidence indicates that delaying the task responses of younger HIV-infected adults increased the probability that the PM relevant features of task stimuli were adequately assessed prior to the ongoing task response, and by implication that younger HIV infected adults can more adequately achieve PM goals when the pace of the task environment is slowed down.

Event-based prospective memory is independently associated with self-report of medication management in older adults

BACKGROUND

Identifying potentially modifiable risk factors for medication non-adherence in older adults is important in order to enhance screening and intervention efforts designed to improve medication-taking behavior and health outcomes. The current study sought to determine the unique contribution of prospective memory (PM) (i.e. 'remembering to remember') to successful self-reported medication management in older adults.

METHODS

Sixty-five older adults with current medication prescriptions completed a comprehensive research evaluation of sociodemographic, psychiatric, and neurocognitive functioning, which included the memory for adherence to medication scale (MAMS), prospective and retrospective memory questionnaire (PRMQ), and a performance-based measure of PM that measured both semantically related and semantically unrelated cue-intention (i.e. when-what) pairings.

RESULTS

A series of hierarchical regressions controlling for biopsychosocial, other neurocognitive, and medication-related factors showed that elevated complaints on the PM scale of the PRMQ and worse performance on an objective semantically unrelated event-based PM task were independent predictors of poorer medication adherence as measured by the MAMS.

CONCLUSIONS

PM plays an important role in self-report of successful medication management among older adults. Findings may have implications for screening for older individuals 'at risk' of non-adherence, as well as the development of PM-based interventions to improve medication adherence and, ultimately, long-term health outcomes in older adults.

Task importance affects event-based prospective memory performance in adults with HIV-associated neurocognitive disorders and HIV-infected young adults with problematic substance use

Two experiments were conducted to examine the effects of task importance on event-based prospective memory (PM) in separate samples of adults with HIV-associated neurocognitive disorders (HAND) and HIV-infected young adults with substance use disorders (SUD). All participants completed three conditions of an ongoing lexical decision task: (1) without PM task requirements; (2) with PM task requirements that emphasized the importance of the ongoing task; and (3) with PM task requirements that emphasized the importance of the PM task. In both experiments, all HIV+ groups showed the expected increase in response costs to the ongoing task when the PM task's importance was emphasized. In Experiment 1, individuals with HAND showed significantly lower PM accuracy as compared to HIV+ subjects without HAND when the importance of the ongoing task was emphasized, but improved significantly and no longer differed from HIV+ subjects without HAND when the PM task was emphasized. A similar pattern of findings emerged in Experiment 2, whereby HIV+ young adults with SUD (especially cannabis) showed significant improvements in PM accuracy when the PM task was emphasized. Findings suggest that both HAND and SUD may increase the amount of cognitive attentional resources that need to be allocated to support PM performance in persons living with HIV infection.

Successful cognitive aging and health-related quality of life in younger and older adults infected with HIV

Neurocognitive impairments commonly occur and adversely impact everyday functioning in older adults infected with HIV, but little is known about successful cognitive aging (SCA) and its health-related quality of life (HRQoL) correlates. Seventy younger (≤40 years) and 107 older (≥50 years) HIV+ adults, as well as age-matched seronegative comparison groups of younger (N = 48) and older (N = 77) subjects completed a comprehensive battery of neuropsychological, psychiatric, medical, and HRQoL assessments. SCA was operationalized as the absence of both performance-based neurocognitive deficits and self-reported symptoms (SCA-ANDS) as determined by published normative standards. A stair-step decline in SCA-ANDS was observed in accordance with increasing age and HIV serostatus, with the lowest rates of SCA-ANDS found in the older HIV+ group (19 %). In both younger and older HIV+ adults, SCA-ANDS was strongly related to better mental HRQoL. HIV infection has additive adverse effects on SCA, which may play a unique role in mental well-being among HIV-infected persons across the lifespan.

Human immunodeficiency virus infection heightens concurrent risk of functional dependence in persons with long-term methamphetamine use

OBJECTIVES

Disability among long-term methamphetamine (MA) users is multifactorial. This study examined the additive adverse impact of human immunodeficiency virus (HIV) infection, a common comorbidity in MA users, on functional dependence.

METHODS

A large cohort of participants (N = 798) stratified by lifetime MA-dependence diagnoses (ie, MA+ or MA-) and HIV serostatus (ie, HIV+ or HIV-) underwent comprehensive baseline neuromedical, neuropsychiatric, and functional research evaluations, including assessment of neurocognitive symptoms in daily life, instrumental and basic activities of daily living, and employment status.

RESULTS

Independent, additive effects of MA and HIV were observed across all measures of functional dependence, independent of other demographic, psychiatric, and substance-use factors. The prevalence of global functional dependence increased in the expected stepwise fashion across the cohort, with the lowest rates in the MA-/HIV- group (29%) and the highest rates in the MA+/HIV+ sample (69%). The impact of HIV on MA-associated functional dependence was moderated by nadir CD4 count, such that polysubstance use was associated with greater disability among those HIV-infected persons with higher but not lower nadir CD4 count. Within the MA+/HIV+ cohort, functional dependence was reliably associated with neurocognitive impairment, lower cognitive reserve, polysubstance use, and major depressive disorder.

CONCLUSIONS

HIV infection confers an increased concurrent risk of MA-associated disability, particularly among HIV-infected persons without histories of immune compromise. Directed referrals, earlier HIV treatment, and compensatory strategies aimed at counteracting the effects of low cognitive reserve, neurocognitive impairment, and psychiatric comorbidities on functional dependence in MA+/HIV+ individuals may be warranted.

Construct validity of the Memory for Intentions Screening Test (MIST) in healthy older adults

The Memory for Intentions Screening Test (MIST) is a clinical measure of prospective memory. There is emerging support for the sensitivity and ecological relevance of the MIST in clinical populations. In the present study, the construct validity of the MIST was evaluated in 40 younger (18-30 years), 24 young-old (60-69 years), and 37 old-old (70+ years) healthy adults. Consistent with expectations derived from the prospective memory and aging literature, older adults demonstrated lower scores on the MIST's primary scale scores (particularly on the time-based scale), but slightly better performance on the seminaturalistic 24-hour trial. Among the healthy older adults, the MIST showed evidence of both convergent (e.g., verbal fluency) and divergent (e.g., visuoperception) correlations with standard clinical tests, although the magnitude of those correlations were comparable across the time- and event-based scales. Together, these results support the discriminant and convergent validity of the MIST as a measure of prospective memory in healthy older adults.

Shallow encoding and forgetting are associated with dependence in instrumental activities of daily living among older adults living with HIV infection

Aging and HIV are both risk factors for memory deficits and declines in real-world functioning. However, we know little about the profile of memory deficits driving instrumental activities of daily living (IADL) declines across the lifespan in HIV. This study examined 145 younger (<50 years) and 119 older (≥50 years) adults with HIV who completed the California Verbal Learning Test-Second Edition (CVLT-II), the Wechsler Memory Scale-Third Edition Logical Memory subtest (WMS-III LM), and a modified Lawton and Brody ADL questionnaire. No memory predictors of IADL dependence emerged in the younger cohort. In the older group, IADL dependence was uniquely associated with worse performance on all primary CVLT-II variables, as well as elevated recency effects. Poorer immediate and delayed recall of the WMS-III LM was also associated with IADL dependence, although recognition was intact. Findings suggest older HIV-infected adults with shallow encoding and forgetting are at risk for IADL dependence.

Visuospatial temporal order memory deficits in older adults with HIV infection

OBJECTIVE

To compare temporal order memory in older adults with and without human immunodeficiency virus (HIV) infection.

BACKGROUND

The frontal and temporal lobes play a key role in temporal order memory for items in a sequence. HIV-associated episodic memory deficits correlate with damage to neocortical interneurons in the fronto-striato-thalamo-cortical pathway and with atypical activation of the medial temporal lobes. Therefore, temporal order memory may be sensitive to neuropathological changes in individuals with HIV.

METHODS

In this study, 50 HIV-seropositive individuals aged ≥ 50 years and 50 seronegative controls performed a computerized visuospatial temporal order memory task. During the sample phase of each trial, participants were shown circles presented 1 at a time in a random sequence at the end of each of the 8 arms of a radial maze. During the choice phase, they were shown the maze with a circle at the ends of 2 of the arms and asked which circle had appeared earlier than the other in the original sequence.

RESULTS

Performance in both groups improved as a function of greater temporal separation between circle presentations. However, the HIV group had significantly worse memory impairment across all temporal separations, and the impairment was independently associated with clinical deficits in executive function and delayed retrospective memory.

CONCLUSIONS

Our results extend prior findings that HIV is associated with deficits in strategic aspects of memory encoding and retrieval. The neural mechanisms warrant further research, as do potential impacts on everyday function, eg, adherence to antiretroviral drug regimens.

Detrimental impact of remote methamphetamine dependence on neurocognitive and everyday functioning in older but not younger HIV+ adults: evidence for a legacy effect?

Prior studies examining the combined adverse effects of HIV and methamphetamine (MA) on the central nervous system (CNS) have focused on younger to middle-aged adults with recent MA use diagnoses. Aging, HIV, and MA all converge on prefrontal and temporolimbic neural systems and confer independent risk for neurocognitive and functional decline. Thus, this study sought to determine the residual impact of a remote history of MA dependence on neurocognitive and real-world outcomes in older people living with HIV (PLWH). Participants included 116 older (≥50 years) and 94 younger (<40 years) adults classified into one of six study groups based on HIV serostatus (HIV+/HIV-) and lifetime histories of MA dependence (MA+/MA-): older HIV-MA- (n = 36), older HIV+MA- (n = 49), older HIV+MA+ (n = 31), younger HIV-MA- (n = 27), younger HIV+MA- (n = 33), and younger HIV+MA+ (n = 34). No participant-met criteria for current MA use disorders and histories of MA dependence were remote in both the older (average of nearly 9 years prior to evaluation) and younger (average of over 2 years prior to evaluation) HIV+MA+ groups. Findings revealed that a remote history of MA dependence exerts a significant detrimental impact on specific aspects of neurocognitive performance (e.g., memory) and a broad range of real-world functioning outcomes (e.g., employment) among older, but not younger PLWH. These results suggest that MA-associated neurotoxicity may have significant "legacy" effects on both neurocognitive and functional outcomes to which older PLWH are particularly vulnerable.

Neurocognitive functioning in antiretroviral therapy-naïve youth with behaviorally acquired human immunodeficiency virus

PURPOSE

Youth living with human immunodeficiency virus (HIV) account for over one third of new HIV infections and are at high risk of adverse psychosocial, everyday living, and health outcomes. Human immunodeficiency virus-associated neurocognitive disorders (HAND) are known to affect health outcomes of HIV-infected adults even in the era of combination antiretroviral therapy. Thus, the current study aimed to characterize the prevalence and clinical correlates of HAND in youth living with HIV. Here, we report baseline neurocognitive data for behaviorally HIV-infected youth enrolled in a prospective study evaluating strategies of antiretroviral treatment initiation and use.

METHODS

A total of 220 participants, age 18-24 years, who were naive to treatment (except for prevention of mother-to-child HIV transmission; n = 3), completed a comprehensive neurocognitive, substance use, and behavioral health assessment battery.

RESULTS

Sixty-seven percent of youth met criteria for HAND (96.4% were asymptomatic and 3.5% were syndromic); deficits in episodic memory and fine-motor skills emerged as the most commonly affected ability areas. Multivariable models showed that lower CD4 count, longer time since HIV diagnosis, and high-risk alcohol use were uniquely associated with neurocognitive deficits.

CONCLUSIONS

Over two thirds of youth with behaviorally acquired HIV evidence neurocognitive deficits, which have modest associations with more advanced HIV disease as well as other factors. Research is needed to determine the impact of such neuropsychiatric morbidity on mental health and HIV disease treatment outcomes (e.g., nonadherence) and transition to independent living responsibilities in HIV-infected youth, as well as its long-term trajectory and possible responsiveness to cognitive rehabilitation and pharmacotherapy.

Time-based prospective memory predicts engagement in risk behaviors among substance users: results from clinical and nonclinical samples

Deficits in prospective memory (PM; i.e., enacting previously learned actions at the right occasion) and risky decision-making (i.e., making choices with a high chance of undesirable/dangerous outcomes) are both common among individuals with substance use disorders (SUD). Previous research has raised the possibility of a specific relationship between PM and risk-taking, and the present study aimed to systematically study if PM provides unique variance in the prediction of risky decision-making. Two samples were included: (1) a group of 45 individuals with SUD currently in treatment, and (2) a nonclinical group of 59 university students with high-risk drinking and/or substance use. Regression analyses indicated that time-based, but not event-based, PM predicted increased risky behavior (e.g., risky sexual practices and criminal behaviors) in both groups after controlling for demographic, psychiatric, and substance use variables, as well as other neuropsychological functions. The current findings contribute to the growing literature supporting the role of PM as a predictor of everyday functioning, and suggest that cognitive rehabilitation may be an important avenue of research as an adjunct to traditional substance use treatment, particularly in addressing the potential adverse effects of PM deficits in the implementation of treatment-related homework activities and risk management strategies.

Apolipoprotein E4 genotype does not increase risk of HIV-associated neurocognitive disorders

This is a cross-sectional, observational study to evaluate the hypothesis that HIV-seropositive (HIV+) apolipoprotein E4 (APOE4) carriers are at increased risk for HIV-associated neurocognitive disorders (HAND) compared to APOE4 noncarriers with HIV in the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) Group sample. APOE genotype was determined in 466 CHARTER participants with varying disease stages and histories of antiretroviral treatment who did not have severe psychiatric or medical comorbid conditions that preclude diagnosis of HAND. HAND diagnoses were based on results of comprehensive neurobehavioral evaluation and use of current neuroAIDS diagnostic criteria. HAND status consists of two levels: neuropsychologically normal status (i.e., no HAND) and any HAND diagnosis (i.e., asymptomatic neurocognitive impairment, minor neurocognitive disorder, HIV-associated dementia). Logistic regression analyses revealed no association between APOE4 carrier status and HAND, and there were no interactions between APOE4 carrier status and ethnicity, age, substance use disorders, duration of infection, or nadir CD4. Results did not differ when analysis was restricted to symptomatic HAND, and no APOE4 gene dose-dependent relationship to HAND emerged. APOE4 status was not associated with concurrent HAND in this large, well-characterized sample. This does not preclude emergence of an association between APOE4 status and HAND as this population ages. Prospective, longitudinal studies are needed to examine APOE4 as a risk factor for neurocognitive decline, incident HAND at older ages, and potential associations with cerebrospinal fluid amyloid.

Co-morbidities in persons infected with HIV: increased burden with older age and negative effects on health-related quality of life

This study sought to determine the synergistic effects of age and HIV infection on medical co-morbidity burden, along with its clinical correlates and impact on health-related quality of life (HRQoL) across the lifespan in HIV. Participants included 262 individuals across four groups stratified by age (≤40 and ≥50 years) and HIV serostatus. Medical co-morbidity burden was assessed using a modified version of the Charlson Co-morbidity Index (CCI). Multiple regression accounting for potentially confounding demographic, psychiatric, and medical factors revealed an interaction between age and HIV infection on the CCI, with the highest medical co-morbidity burden in the older HIV+cohort. Nearly half of the older HIV+group had at least one major medical co-morbidity, with the most prevalent being diabetes (17.8%), syndromic neurocognitive impairment (15.4%), and malignancy (12.2%). Affective distress and detectable plasma viral load were significantly associated with the CCI in the younger and older HIV-infected groups, respectively. Greater co-morbidity burden was uniquely associated with lower physical HRQoL across the lifespan. These findings highlight the prevalence and clinical impact of co-morbidities in older HIV-infected adults and underscore the importance of early detection and treatment efforts that might enhance HIV disease outcomes.

Aging, prospective memory, and health-related quality of life in HIV infection

HIV infection and older age are each independently associated with lower health-related quality of life (HRQoL) and deficits in prospective memory (PM), which is a distinct aspect of cognition involving the ability to "remember to remember" to do something at a future occasion. The present study investigated associations between PM and HRQoL in 72 older (≥ 50 years) and 41 younger (≤ 40 years) HIV-infected adults. Self-reported PM complaints predicted HRQoL across the entire sample, but there was a significant interaction between performance-based PM and age group on HRQoL, such that lower time-based PM was associated with lower HRQoL only in the younger cohort. Within the younger group, time-based and self-reported PM significantly predicted mental HRQoL independent of other risk factors (e.g. depression). These findings suggest that PM plays a unique role in HRQoL outcomes among younger persons living with HIV infection and support the examination of other age-related factors (e.g. effective use of compensatory strategies) that may regulate the adverse impact of PM on everyday functioning.

Longer ongoing task delay intervals exacerbate prospective memory deficits in HIV-associated neurocognitive disorders (HAND)

The delay interval between encoding a future intention and detection of the retrieval cue is an essential feature of prospective memory (PM). McDaniel and Einstein's ( 2000 ) multiprocess theory posits that greater demands are placed on strategic monitoring processes as the delay interval lengthens. This hypothesis was examined in HIV-associated neurocognitive disorders (HAND), which are associated with strategic dyscontrol of PM, likely secondary to prefrontostriatal circuit pathology. Seventy-eight seronegative adults and 49 individuals with HAND comprised the study groups, which were comparable with regard to demographic, psychiatric, and substance use factors. As part of a comprehensive neuropsychological evaluation, participants were administered a well-validated PM measure that included short (2-min) and long (15-min) task delay interval scales that utilized a standardized word search as the ongoing task. Results revealed a significant interaction of group and delay interval, with significant effects of HAND on PM at long, but not short, delay. The long-delay PM effect in HAND was driven primarily by deficits in time-based PM and was most strongly associated with markers of executive dysfunction. In concordance with the multiprocess theory, individuals with HAND were disproportionately vulnerable to PM deficits at longer ongoing task delay intervals, which appear to be driven by strategic dyscontrol of PM that is consistent with the preferential disruption of prefrontal systems in neuroAIDS (neurological complications of AIDS). Difficulty with successfully completing PM tasks following a longer delay could manifest in real-world problems, such as medication nonadherence and unemployment, and characterizing this specific deficit may inform remediation strategies.

The role of prospective memory in medication adherence: a review of an emerging literature

Although neurocognitive impairment is an established risk factor for medication nonadherence, standard neurocognitive tests developed for clinical purposes may not fully capture the complexities of non-adherence behavior or effectively inform theory-driven interventions. Prospective memory, an innovative cognitive construct describing one's ability to remember to do something at a later time, is an understudied factor in the detection and remediation of medication non-adherence. This review orients researchers to the construct of prospective memory, summarizes empirical evidence for prospective memory as a risk factor for non-adherence, discusses the relative merits of current measurement techniques, and highlights potential prospective memory-focused intervention strategies. A comprehensive literature review was conducted of published empirical studies investigating prospective memory and medication adherence. Overall, reviewed studies suggest that prospective memory is an important component of medication adherence, providing incremental ecological validity over established predictors. Findings indicate that prospective memory-based interventions might be an effective means of improving adherence.

Combined effects of aging and HIV infection on semantic verbal fluency: a view of the cortical hypothesis through the lens of clustering and switching

The profile of HIV-associated neurocognitive disorders (HAND) has classically been characterized as "subcortical," but questions have arisen as to whether aging with HIV in the antiretroviral therapy era has subtly shifted the expression of HAND into a more "cortical" disorder (e.g., decay of semantic memory stores). We evaluated this hypothesis by examining semantic fluency and its component processes (i.e., clustering and switching) in 257 individuals across four groups stratified by age (<40 and ≥50 years) and HIV serostatus. Jonckheere-Terpstra tests revealed significant monotonic trends for the combined effects of HIV and aging on overall semantic (and letter) fluency and switching, but not cluster size, with greatest deficits evident in the older adults with HIV infection. Within the older HIV-infected cohort, poorer switching was uniquely associated with self-reported declines in instrumental activities of daily living and deficits in learning and executive functions, but not semantic memory. Results suggest that HIV infection and aging may confer adverse additive effects on the executive components of semantic fluency (i.e., switching), rather than a degradation of semantic memory stores (i.e., cluster size), which is a profile that is most consistent with combined frontostriatal neuropathological burden of these two conditions.

An examination of the age-prospective memory paradox in HIV-infected adults

The age-prospective memory (PM) paradox asserts that, despite evidence of age-associated PM deficits on laboratory tasks, older adults perform comparably to (or better than) young adults on naturalistic PM tasks. This study examined the age-PM paradox in older HIV-infected individuals, who represent a growing epidemic and may be at heightened risk for adverse neurocognitive and everyday functioning outcomes. Participants included 88 older (50+ years) and 53 younger (≤40 years) HIV-infected individuals as well as 54 older and 59 younger seronegative adults who completed both laboratory and naturalistic time-based PM tasks. Similar interactions were observed in both the seropositive and the seronegative samples, such that the older participants demonstrated significantly lower laboratory-based PM than the younger groups, but not on the naturalistic PM trial. Secondary analyses within the HIV+ sample revealed that naturalistic task success was indirectly associated with greater self-reported use of PM-based and external compensatory strategies in the daily lives of older, but not younger, HIV+ adults. Study findings suggest that, although older HIV-infected adults exhibit moderate PM deficits on laboratory measures versus their younger counterparts, such impairments are paradoxically not evident on ecologically relevant naturalistic PM activities in daily life, perhaps related to effective utilization compensatory strategies.