Objective

HIV is associated with frontostriatal dysregulation and executive dysfunction. This study evaluated whether HIV-infected individuals evidence deficits in random number generation (RNG), which is a strategic task requiring paced, rule-guided production of digits.

Method

In total, 74 HIV+ adults and 54 seronegative comparison participants completed a comprehensive research neuropsychological battery. Participants produced a random digit sequence by avoiding any order and using numbers 1 through 10 for 100 s at a pace of 1 digit/s. Outcomes included intrusions, repetitions, seriation (1-2-3-4), and cycling (median length of gaps between repeating digits).

Results

HIV disease was associated with higher levels of seriation and cycling (ps < .05) but not intrusions or repetitions (ps > .10). Among HIV+ individuals, higher seriation was associated with neuropsychological performance including poorer auditory attention, verbal learning, and delayed memory, whereas higher cycling scores were associated with poorer delayed memory and verbal fluency (ps < .05). Higher seriation also was independently associated with self-reported declines in activities of daily living (ADLs) in the HIV+ group.

Conclusions

Individuals living with HIV disease evidence moderate difficulties in inhibiting statistically unlikely non-random sequences, which showed medium associations with higher order verbal abilities and may contribute to greater declines in everyday functioning outcomes. Future studies might examine RNG's role in health behaviors such as medical decision-making or medication adherence.

Objective

HIV is associated with frontostriatal dysregulation and executive dysfunction. This study evaluated whether HIV-infected individuals evidence deficits in random number generation (RNG), which is a strategic task requiring paced, rule-guided production of digits.

Method

In total, 74 HIV+ adults and 54 seronegative comparison participants completed a comprehensive research neuropsychological battery. Participants produced a random digit sequence by avoiding any order and using numbers 1 through 10 for 100 s at a pace of 1 digit/s. Outcomes included intrusions, repetitions, seriation (1-2-3-4), and cycling (median length of gaps between repeating digits).

Results

HIV disease was associated with higher levels of seriation and cycling (ps < .05) but not intrusions or repetitions (ps > .10). Among HIV+ individuals, higher seriation was associated with neuropsychological performance including poorer auditory attention, verbal learning, and delayed memory, whereas higher cycling scores were associated with poorer delayed memory and verbal fluency (ps < .05). Higher seriation also was independently associated with self-reported declines in activities of daily living (ADLs) in the HIV+ group.

Conclusions

Individuals living with HIV disease evidence moderate difficulties in inhibiting statistically unlikely non-random sequences, which showed medium associations with higher order verbal abilities and may contribute to greater declines in everyday functioning outcomes. Future studies might examine RNG's role in health behaviors such as medical decision-making or medication adherence.

HIV-associated neurocognitive disorders (HAND) are associated with deficits in prospective memory (PM; "remembering to remember"), conferring risk of daily functioning declines. However, self-perceptions of PM functioning are not reliably associated with PM performance in HIV, suggesting a possible deficit in awareness of PM abilities (meta-PM). Our study examined meta-PM in HAND and its correlates using self-predictions of laboratory-based PM performance. Performance-based PM abilities, self-reported prediction of PM performance, and PM complaints in everyday life were assessed in 49 individuals with HAND, 93 HIV+ without HAND (HIV+ noHAND), and 121 seronegative adults (HIV-). After controlling for group-level differences, HAND was associated with a greater number of PM symptoms in everyday life and worse PM performance when compared with both HIV+ noHAND and HIV- samples. Although HAND individuals reported somewhat lower predictions regarding their laboratory PM performance relative to the other study groups, they nevertheless exhibited significantly greater inaccurate overconfidence in time-based PM abilities. Within the HAND group, overconfidence in time-based meta-PM was associated with executive dysfunction and antiretroviral (ARV) nonadherence. HAND individuals evidenced a moderate deficit in awareness of PM functioning characterized by overconfidence in time-based PM abilities. Overconfidence in PM may result in absence of compensatory strategy use, and lead to increased errors in daily functioning (e.g., ARV nonadherence).

This study evaluated the effects of HIV-associated Neurocognitive Disorders (HAND) on 2 Internet-based tests of healthcare management. Study participants included 46 individuals with HIV infection, 19 of whom were diagnosed with HAND, and 21 seronegatives. Participants were administered Internet-based tests of online pharmacy and health records navigation skills in which they used mock credentials to log in to an experimenter-controlled website and independently perform a series of typical online health-related behaviors (e.g., refill a prescription, read and interpret an electronic chart note). HAND was associated with significantly lower accuracy on both the online pharmacy and health records navigation tasks. Among the HIV+ participants, poorer performance on the online healthcare navigation tasks was associated with fewer years of education, higher plasma viral load, less frequent Internet use, and lower health literacy. Findings indicate that individuals with HAND may have marked difficulties navigating the Internet to complete important health-related behaviors.

Objective

HIV-associated neurocognitive disorders (HAND) are associated with deficits in prospective memory (PM). However, most PM research in HIV has used single-event tasks as opposed to habitual PM paradigms, which may be more relevant to clinical populations for whom many health-care behaviors must be performed both frequently and routinely.

Method

For the current study, we examined habitual PM and its associations with real-world functioning outcomes in 36 HIV+ individuals with HAND (HAND+), 70 HIV+ individuals without HAND (HAND-), and 115 HIV- individuals. The ongoing task consisted of 24 1-min Stroop trial blocks in which the emotive and cognitive load was manipulated. The habitual PM task required participants to press the spacebar once per block, but only after 20 s had elapsed.

Results

A series of MANOVAs covarying for relevant clinicodemographic factors revealed a main effect of study group on habitual PM, such that the HAND+ cohort made significantly more repetition errors than the HIV- and HAND- groups, particularly during early trial blocks. There was no main effect of ongoing task demands, nor was there an interaction between HAND group and task demands. Within the entire HIV+ sample, poorer habitual PM was associated with deficits in learning and dysfunction in real-world outcomes, including medication nonadherence and failures on a naturalistic health-care task.

Conclusion

Findings indicate that HAND may be associated with deficient internal source monitoring or temporal discrimination for habitual PM output that may play a critical role in real-world functioning, including HIV disease management.

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.

Methamphetamine (MA) dependence is associated with executive dysfunction, but no studies have evaluated MA-related elevations in neurocognitive intraindividual variability (IIV), an expression of cognitive dyscontrol linked to poor daily functioning in populations with frontal systems injury. We examined IIV during a vigilance task in a well-characterized sample of 35 MA-dependent (MA+) and 55 non-MA using comparison participants (MA-) as part of a larger neuropsychological battery that included self-report and performance-based measures of everyday functioning. A mixed model ANOVA was conducted while controlling for covariates, including factors that differed between the groups (e.g., education) and those with conceptual relevance to IIV: mean reaction time, global cognitive performance, and HIV-infection (which was comparable across groups; p=0.32). This analysis revealed significantly elevated IIV among MA+ relative to MA- individuals that was comparable in magnitude across all trial blocks of the vigilance task. Within the MA group, elevated IIV was associated with executive dysfunction, psychomotor slowing, and recency of MA use, as well as poorer automobile driving simulator performance, worse laboratory-based functional skills, and more cognitive complaints. MA-users are vulnerable to IIV elevation, likely due to cognitive dyscontrol, which may increase their risk of real-world problems.

With the rising number of individuals in their 50s and 60s who are infected with HIV, concerns have emerged about possible increases in the rates of non-HIV-associated dementias. The current study examined the prevalence of mild cognitive impairment (MCI) in older HIV-infected adults, since MCI is an intermediate state between typical cognitive aging and dementia that emerges in this age range. Participants included 75 adults with HIV disease aged 50 years and older who were on combination antiretroviral therapy (cART) and had undetectable plasma viral loads and 80 demographically similar HIV-seronegative comparison subjects. Participants completed a research neuropsychological evaluation that was used to classify MCI according to the comprehensive diagnostic scheme described by Bondi et al. (J Alzheimers Dis 42:275-289, 2014). HIV-infected persons were over seven times more likely to have an MCI designation (16 %) than their seronegative counterparts (2.5 %). Within the HIV+ cohort, MCI had minimal overlap with diagnoses of asymptomatic neurocognitive impairment and was significantly associated with older age, lower Karnofsky Scale of Performance Scores, and mild difficulties performing instrumental activities of daily living (iADLs). HIV infection in older adults is associated with a notably elevated concurrent risk of MCI, which may increase the likelihood of developing non-HIV-associated dementias as this population ages further.

Background and objective

Acute and early human immunodeficiency virus infection (AEH) is accompanied by neuroinflammatory processes as well as impairment in neurocognitive and everyday functions, but little is known about the frequency and clinical correlates of the neurobehavioral disturbances during this period. We compared pre-seroconversion with current levels of apathy, disinhibition, and executive dysfunction; we also examined everyday function and HIV disease correlates of neuropsychiatric impairment in individuals with AEH.

Methods

In this study, 34 individuals with AEH and 39 HIV-seronegative participants completed neuromedical and neuropsychological assessments, a structured psychiatric interview, and the apathy, disinhibition, and executive dysfunction subscales of the Frontal Systems Behavioral Scale.

Results

Independent of any substance use and mood disorders, the AEH group had significantly higher levels of current apathy and executive dysfunction than the controls, but not greater disinhibition. Retrospective ratings of pre-seroconversion levels of apathy, disinhibition, and executive dysfunction were all higher in the AEH group than the controls. After seroconversion, the AEH cohort had increases in current apathy and executive dysfunction, but not disinhibition. In the AEH cohort, higher current global neurobehavioral dysfunction was significantly associated with lower nadir CD4 counts, slowed information processing speed, and more everyday function problems.

Conclusions

These data suggest that individuals who have recently acquired HIV experienced higher-than-normal premorbid levels of neurobehavioral disturbance. Apathy and executive dysfunction are exacerbated during AEH, particularly in association with lower CD4 counts.

The acute and early period of HIV-1 infection (AEH) is characterized by neuroinflammatory and immunopathogenic processes that can alter the integrity of neural systems and neurocognitive functions. However, the extent to which central nervous system changes in AEH confer increased risk of real-world functioning (RWF) problems is not known. In the present study, 34 individuals with AEH and 39 seronegative comparison participants completed standardized neuromedical, psychiatric, and neurocognitive research evaluations, alongside a comprehensive assessment of RWF that included cognitive symptoms in daily life, basic and instrumental activities of daily living, clinician-rated global functioning, and employment. Results showed that AEH was associated with a significantly increased risk of dependence in RWF, which was particularly elevated among AEH persons with global neurocognitive impairment (NCI). Among those with AEH, NCI (i.e., deficits in learning and information processing speed), mood disorders (i.e., Bipolar Disorder), and substance dependence (e.g., methamphetamine dependence) were all independently predictive of RWF dependence. Findings suggest that neurocognitively impaired individuals with AEH are at notably elevated risk of clinically significant challenges in normal daily functioning. Screening for neurocognitive, mood, and substance use disorders in AEH may facilitate identification of individuals at high risk of functional dependence who may benefit from psychological and medical strategies to manage their neuropsychiatric conditions.