Measurement and Structure of Cognition in the Longitudinal Aging Study in India-Diagnostic Assessment of Dementia.

OBJECTIVES: To test whether a relatively complex model of human cognitive abilities based on Cattell-Horn-Carroll (CHC) theory, developed mainly in English-speaking samples, adequately describes correlations among tests in the Longitudinal Aging Study in India-Diagnostic Assessment of Dementia (LASI-DAD), and to develop accurate measures of cognition for older individuals in India. DESIGN: LASI-DAD participants were recruited from participants aged 60 years and older from 14 states in the core LASI survey, with a stratified sampling design. SETTING: Participants were interviewed at home or in a participating hospital, according to their preferences. PARTICIPANTS: Community-residing older adults aged 60 years and older (N = 3,224). MEASUREMENTS: A variety of cognitive tests were administered during two pretests and chosen for their appropriateness for measuring cognition in older adults in India and suitability for calibration with the core LASI survey and the Harmonized Cognitive Assessment Protocol. RESULTS: We evaluated the factor structure of the test battery and its conformity with a classical CHC factor model that incorporated measurement models for general cognition, five broad domains (orientation, executive functioning, language/fluency, memory, and visuospatial), and five narrow domains (reasoning, attention/speed, immediate memory, delayed memory, and recognition memory) of cognitive performance. Model fit was adequate (root mean square error of approximation = 0.051; comparative fit index = 0.916; standardized root mean squared residual = 0.060). CONCLUSION: We demonstrated configural factorial invariance of a cognitive battery in the Indian LASI-DAD using CHC theory. Broad domain factors may be used in future research to rank individuals with respect to cognitive performance and classify cognitive impairment. J Am Geriatr Soc 68:S11-S19, 2020.

Methodological considerations in designing and implementing the harmonized diagnostic assessment of dementia for longitudinal aging study in India (LASI-DAD).

The Harmonized Diagnostic Assessment of Dementia for Longitudinal Aging Study in India (LASI-DAD) is a population-representative, prospective cohort study of late-life cognition and dementia. It is part of an ongoing international research collaboration that aims to measure and understand cognitive impairment and dementia risk by collecting a set of cognitive and neuropsychological assessments and informant reports, referred to as the Harmonized Cognitive Assessment Protocol (HCAP). LASI-DAD provides nationally representative data drawn from a subsample of the ongoing Longitudinal Aging Study in India (LASI). One of LASI-DAD's distinctive features is its rich geriatric assessment, including the collection of venous blood samples and brain imaging data for a subsample of respondents. In this paper, we discuss the methodological considerations of developing and implementing the HCAP protocol in India. The lessons we learned from translating and applying the HCAP protocol in an environment where illiteracy and innumeracy are high will provide important insights to researchers interested in measuring and collecting data on late-life cognition and dementia in developing countries. We further developed an innovative blood management system that enables us to follow the collection, transportation, assay, and storage of samples. Such innovation can benefit other population surveys collecting biomarker data.

Long-term changes in retinal vascular diameter and cognitive impairment in type 1 diabetes.

OBJECTIVE: To assess associations between cognitive impairment and longitudinal changes in retinal microvasculature, over 18 years, in adults with type 1 diabetes. RESEARCH DESIGN AND METHODS: Participants of the Pittsburgh Epidemiology of Diabetes Complications Study received ≥3 fundus photographs between baseline (1986-1988) and time of cognitive assessment (2010-2015: N = 119; 52% male; mean age and type 1 diabetes duration 43 and 34 years, respectively). Central retinal arteriolar equivalent and central retinal venular equivalent were estimated via computer-based methods; overall magnitude and speed of narrowing were quantified as cumulative average and slope, respectively. Median regression models estimated associations of central retinal arteriolar equivalent and central retinal venular equivalent measures with cognitive impairment status, adjusted for type 1 diabetes duration. Interactions with HbA1c, proliferative retinopathy and white matter hyperintensities were assessed. RESULTS: Compared with participants without cognitive impairment, those with clinically relevant cognitive impairment experienced 1.8% greater and 31.1% faster central retinal arteriolar equivalent narrowing during prior years (t = -2.93, p = 0.004 and t = -3.97, p < 0.0001, respectively). Interactions with HbA1c, proliferative retinopathy and white matter hyperintensities were not significant. No associations were found between central retinal arteriolar equivalent at baseline, at time of cognitive testing, or any central retinal venular equivalent measures, and cognitive impairment. CONCLUSION: Long-term arterial retinal changes could indicate type 1 diabetes-related cognitive impairment. Studies examining longitudinal central retinal arteriolar equivalent changes as early biomarkers of cognitive impairment risk are warranted.

Genetic Risk Score Predicts Late-Life Cognitive Impairment.

Introduction. A family history of Alzheimer's disease is a significant risk factor for its onset, but the genetic risk associated with possessing multiple risk alleles is still poorly understood. Methods. In a sample of 95 older adults (Mean age = 75.1, 64.2% female), we constructed a genetic risk score based on the accumulation of risk alleles in BDNF, COMT, and APOE. A neuropsychological evaluation and consensus determined cognitive status (44 nonimpaired, 51 impaired). Logistic regression was performed to determine whether the genetic risk score predicted cognitive impairment above and beyond that associated with each gene. Results. An increased genetic risk score was associated with a nearly 4-fold increased risk of cognitive impairment (OR = 3.824, P = .013) when including the individual gene polymorphisms as covariates in the model. Discussion. A risk score combining multiple genetic influences may be more useful in predicting late-life cognitive impairment than individual polymorphisms.

Cognitive testing in older primary care patients: A cluster-randomized trial.

INTRODUCTION: This study investigated whether neuropsychological testing in primary care (PC) offices altered physician-initiated interventions related to cognitive impairment (CI) or slowed the rate of CI progression. METHODS: This 24-month, cluster-randomized study included 11 community-based PC practices randomized to either treatment as usual (5 practices) or cognitive report (CR; 6 practices) arms. From 2005 to 2008, 533 patients aged ≥65 years and without a diagnosis of CI were recruited; 423 were retested 24 months after baseline. RESULTS: CR physicians were significantly more likely to order cognitive-related interventions (P = .02), document discussions about cognition (P = .003), and order blood tests to rule out reversible CI (P = .002). At follow-up, significantly more CR patients had a medication for cognition listed in their chart (P = .02). There was no difference in the rate of cognitive decline between the groups. DISCUSSION: Providing cognitive information to physicians resulted in higher rates of physician-initiated interventions for patients with CI.

Trajectories of peripheral interleukin-6, structure of the hippocampus, and cognitive impairment over 14 years in older adults.

We aimed to investigate if trajectory components (baseline level, slope, and variability) of peripheral interleukin-6 (IL-6) over time were related to cognitive impairment and smaller hippocampal volume and if hippocampal volume explained the associations between IL-6 and cognitive impairment. Multivariable regression models were used to test the association between IL-6 trajectory components with change in neuroimaging measures of the hippocampus and with cognitive impairment among 135 older adults (70-79 years at baseline) from the Healthy Brain Project over 14 years. IL-6 variability was positively associated with cognitive impairment (odds ratio [OR] = 5.86, 95% confidence interval [CI]: 1.24, 27.61) and with greater decrease per year of gray matter volume of the hippocampus (ß = -0.008, standard error = 0.004, p = 0.03). After adjustment for hippocampal volume, the OR of cognitive impairment decreased for each unit of IL-6 variability and CIs widened (OR = 4.36, 95% CI: 0.67, 28.29). Neither baseline levels nor slopes of IL-6 were related to cognitive impairment or hippocampal volume. We believe this has potential clinical and public health implications by suggesting adults with stable levels of peripheral IL-6 may be better targets for intervention studies for slowing or preventing cognitive decline.

Age of Childhood Onset in Type 1 Diabetes and Functional Brain Connectivity in Midlife.

OBJECTIVES: The development of Type 1 diabetes mellitus (T1DM) within the first 7 years of life has been linked to poorer cognitive performance. Adults with T1DM have altered functional brain connectivity, but no studies have examined whether earlier age of T1DM onset is associated with functional connectivity later in life. Accordingly, we tested the relationship between age of onset and resting state functional connectivity in a cohort of middle-aged adults with childhood-onset T1DM. METHODS: Participants were from a subsample of the Pittsburgh Epidemiology of Diabetes Complications cohort and included 66 adults (mean age = 47.54 years, 32 men). Resting state blood oxygen level-dependent activity was used to calculate mean connectivity for eight functional brain networks. A multivariate analysis of variance examined associations between age of onset and network connectivity. Diffusion tensor and fluid-attenuated inversion recovery images were analyzed to identify microstructural alterations and white-matter hyperintensity volumes. RESULTS: Later childhood onset of T1DM was associated with lower connectivity (F(8,57) = 2.40, p = .026). A significant interaction was present for current age such that an inverse association with age of onset for functional connectivity was present in older individuals (F(8,55) = 2.88, p = .035). Lower connectivity was associated with older age, increased white-matter hyperintensity volume, and lower microstructural integrity. CONCLUSIONS: Diagnosis of T1DM later in childhood may be associated with lower brain functional connectivity, particularly in those surviving into older ages. These alterations may be an early marker for subsequent cognitive decrements. Future studies are warranted to understand the pathways underlying these associations.

Clinically Relevant Cognitive Impairment in Middle-Aged Adults With Childhood-Onset Type 1 Diabetes.

OBJECTIVE: The aim of this study was to investigate the presence and correlates of clinically relevant cognitive impairment in middle-aged adults with childhood-onset type 1 diabetes (T1D). RESEARCH DESIGN AND METHODS: During 2010-2013, 97 adults diagnosed with T1D and aged <18 years (age and duration 49 ± 7 and 41 ± 6 years, respectively; 51% female) and 138 similarly aged adults without T1D (age 49 ± 7 years; 55% female) completed extensive neuropsychological testing. Biomedical data on participants with T1D were collected periodically since 1986-1988. Cognitive impairment status was based on the number of test scores ≥1.5 SD worse than demographically appropriate published norms: none, mild (only one test), or clinically relevant (two or more tests). RESULTS: The prevalence of clinically relevant cognitive impairment was five times higher among participants with than without T1D (28% vs. 5%; P < 0.0001), independent of education, age, or blood pressure. Effect sizes were large (Cohen d 0.6-0.9; P < 0.0001) for psychomotor speed and visuoconstruction tasks and were modest (d 0.3-0.6; P < 0.05) for measures of executive function. Among participants with T1D, prevalent cognitive impairment was related to 14-year average A1c >7.5% (58 mmol/mol) (odds ratio [OR] 3.0; P = 0.009), proliferative retinopathy (OR 2.8; P = 0.01), and distal symmetric polyneuropathy (OR 2.6; P = 0.03) measured 5 years earlier; higher BMI (OR 1.1; P = 0.03); and ankle-brachial index ≥1.3 (OR 4.2; P = 0.01) measured 20 years earlier, independent of education. CONCLUSIONS: Clinically relevant cognitive impairment is highly prevalent among these middle-aged adults with childhood-onset T1D. In this aging cohort, chronic hyperglycemia and prevalent microvascular disease were associated with cognitive impairment, relationships shown previously in younger populations with T1D. Two additional potentially modifiable risk factors for T1D-related cognitive impairment, vascular health and BMI, deserve further study.

Objective measures of physical activity, white matter integrity and cognitive status in adults over age 80.

The neuroprotective effects of physical activity (PA) are consistently shown in older adults, but the neural substrates, particularly in white matter (WM), are understudied, especially in very old adults with the fastest growth rate and the highest risk of dementia. This study quantified the association between PA and WM integrity in adults over 80. The moderating effects of cardiometabolic conditions, physical functional limitations and WM hyperintensities were also examined, as they can affect PA and brain integrity. Fractional anisotropy (FA) from normal-appearing WM via diffusion tensor imaging and WM hyperintensities were obtained in 90 participants (mean age = 87.4, 51.1% female, 55.6% white) with concurrent objective measures of steps, active energy expenditure (AEE in kcal), duration (min), and intensity (metabolic equivalents, METs) via SenseWear Armband. Clinical adjudication of cognitive status, prevalence of stroke and diabetes, systolic blood pressure, and gait speed were assessed at time of neuroimaging. Participants were on average sedentary (mean ± SD/day: 1766 ± 1345 steps, 202 ± 311 kcal, 211 ± 39 min, 1.8 ± 1.1 METs). Higher steps, AEE and duration, but not intensity, were significantly associated with higher FA. Associations were localized in frontal and temporal areas. Moderating effects of cardiometabolic conditions, physical functional limitations, and WM hyperintensities were not significant. Neither FA nor PA was related to cognitive status. Older adults with a sedentary lifestyle and a wide range of cardiometabolic conditions and physical functional limitations, displayed higher WM integrity in relation to higher PA. Studies of very old adults to quantify the role of PA in reducing dementia burden via WM integrity are warranted.

Cognitive aging in persons with minimal amyloid-ß and white matter hyperintensities.

Substantial individual differences exist in the magnitude of the cognitive decline associated with normal aging. Potential contributors to this intersubject variability include white matter hyperintensities (WMH) and preclinical Alzheimer's disease, evident as increased brain amyloid. This study examined whether older individuals with minimal evidence of WMH and/or brain amyloid-beta (seen on positron emission tomography with the Pittsburgh compound B radiotracer-PiB) still showed significant cognitive decrements compared to the young. Older individuals, conservatively screened for normal range performance on an extensive neuropsychological battery, underwent structural magnetic resonance imaging (MRI) and PiB scans and performed tests of information processing speed, working memory and inhibitory function. The elderly were divided into PiB(+) and PiB(-) groups based on radiotracer retention. There were no significant differences in cognitive performance between PiB(+) and PiB(-) elderly. However, both PiB groups performed significantly worse than did the young on cognitive testing. WMH burden in the same individuals was quantified by consensus ratings using a 10 point scale with a median split defining two groups, WMH(+) and WMH(-). There were no differences in cognitive performance between WMH(+) and WMH(-) individuals, but both WMH groups performed significantly worse than did the young. Older participants who were both PiB(-) and WMH(-) also performed significantly worse than did the young in all three cognitive domains. The present results suggest that normal-elderly individuals whose brain scans show minimal evidence of amyloid deposition or WMH, still demonstrate a major decrement in comparison to younger persons on measures of processing resources and inhibitory efficiency.

The long-term effects of conventional and atypical antipsychotics in patients with probable Alzheimer's disease.

OBJECTIVE: The authors sought to determine the effects of conventional and atypical antipsychotic use on time to nursing home admission and time to death in a group of outpatients with mild to moderate probable Alzheimer's disease. METHOD: The authors examined time to nursing home admission and time to death in 957 patients with the diagnosis of probable Alzheimer's disease who had at least one follow-up evaluation (mean follow-up time, 4.3 years [SD=2.7]; range, 0.78-18.0 years) using Cox proportional hazard models adjusted for age, gender, education level, dementia severity, hypertension, diabetes mellitus, heart disease, extrapyramidal signs, depression, psychosis, aggression, agitation, and dementia medication use. RESULTS: A total of 241 patients (25%) were exposed to antipsychotics at some time during follow-up (conventional, N=138; atypical, N=95; both, N=8). Nursing home admission (63% compared with 23%) and death (69% compared with 34%) were more frequent in individuals taking conventional than atypical antipsychotics. In a model that included demographic and cognitive variables, hypertension, diabetes mellitus, heart disease, incident strokes, and extrapyramidal signs, only conventional antipsychotic use was associated with time to nursing home admission. However, the association was no longer significant after adjustment for psychiatric symptoms. Psychosis was strongly associated with nursing home admission and time to death, but neither conventional nor atypical antipsychotics were associated with time to death. CONCLUSIONS: The use of antipsychotic medications, both conventional and atypical, was not associated with either time to nursing home admission or time to death after adjustment for relevant covariates. Rather, it was the presence of psychiatric symptoms, including psychosis and agitation, that was linked to increased risk of institutionalization and death after adjustment for exposure to antipsychotics.

In vivo assessment of amyloid-ß deposition in nondemented very elderly subjects.

OBJECTIVE: This study examined amyloid-ß (Aß) deposition in 190 nondemented subjects aged ≥82 years to determine the proportion of Aß-positive scans and associations with cognition, apolipoprotein E (APOE) status, brain volume, and Ginkgo biloba (Gb) treatment. METHODS: Subjects who agreed to participate had a brain magnetic resonance imaging and positron emission tomography scan with (11) C-labeled Pittsburgh compound B (PiB) following completion of a Gb treatment clinical trial. The youngest subject in this imaging study was 82 years, and the mean age of the subjects was 85.5 years at the time of the scans; 152 (80%) were cognitively normal, and 38 (20%) were diagnosed with mild cognitive impairment (MCI) at the time of the PiB study. RESULTS: A high proportion of the cognitively normal subjects (51%) and MCI subjects (68%) were PiB-positive. The APOE*4 allele was more prevalent in PiB-positive than in PiB-negative subjects (30% vs 6%). Measures of memory, language, and attentional functions were worse in PiB-positive than in PiB-negative subjects, when both normal and MCI cases were analyzed together; however, no significant associations were observed within either normal or MCI subject groups alone. There was no relationship between Gb treatment and Aß deposition as determined by PiB. INTERPRETATION: The data revealed a 55% prevalence of PiB positivity in nondemented subjects age >80 years and 85% PiB positivity in the APOE*4 nondemented elderly subjects. The findings also showed that long-term exposure to Gb did not affect the prevalence of cerebral Aß deposition.

Cognitive trajectories associated with ß-amyloid deposition in the oldest-old without dementia.

OBJECTIVE: To determine whether a high prevalence (55%) of Aß deposition in a cohort of individuals remaining dementia-free into their 9th and 10th decades is associated with cognitive decline prior to imaging. METHODS: A total of 194 participants (mean age 85.5 years, range 82-95) who completed the Ginkgo Evaluation of Memory Study (GEMS) and remained dementia-free subsequently completed Pittsburgh compound B-PET imaging. We examined cross-sectional associations between Aß status and performance on a broad neuropsychological test battery completed at GEMS entry 7-9 years prior to neuroimaging. We also longitudinally examined cognition over annual evaluations using linear mixed models. RESULTS: At GEMS screening (2000-2002), participants who were Aß-positive in 2009 had lower performance on the Stroop test (p < 0.01) and Raven's Progressive Matrices (p = 0.05), with trend level difference for Block Design (p = 0.07). Longitudinal analyses showed significant slope differences for immediate and delayed recall of the Rey-Osterrieth figure, semantic fluency, and Trail-Making Test parts A and B, indicating greater performance decline prior to neuroimaging for Aß-positive relative to Aß-negative participants (ps < 0.05). CONCLUSIONS: Highly prevalent Aß deposition in oldest-older adults is associated with cognitive decline in visual memory, semantic fluency, and psychomotor speed beginning 7-9 years prior to neuroimaging. Mean differences in nonmemory domains, primarily executive functions, between Aß-status groups may be detectable 7-9 years before neuroimaging.

Classification of amyloid-positivity in controls: comparison of visual read and quantitative approaches.

UNLABELLED: An important research application of amyloid imaging with positron emission tomography (PET) is detection of the earliest evidence of fibrillar amyloid-beta (Aß) deposition. Use of amyloid PET for this purpose, requires a reproducible method for defining a cutoff that separates individuals with no significant Aß deposition from those in which Aß deposition has begun. We previously reported the iterative outlier approach (IO) for the analysis of Pittsburgh Compound-B (PiB) PET data. Developments in amyloid imaging since the initial report of IO have led us to re-examine the generalizability of this method. IO was developed using full-dynamic atrophy-corrected PiB PET data obtained from a group of control subjects with a fairly distinct separation between PiB-positive [PiB(+)] and PiB-negative [PiB(-)] subjects. METHODS: We tested the performance of IO using late-summed tissue ratio data with atrophy correction or with an automated template method without atrophy correction and tested the robustness of the method when applied to a cohort of older subjects in which separation between PiB(+) and PiB(-) subjects was not so distinct. RESULTS: The IO method did not perform consistently across analyses and performed particularly poorly when separation was less clear. We found that a sparse k-means (SKM) cluster analysis approach performed significantly better; performing more consistently across methods and subject cohorts. We also compared SKM to a consensus visual read approach and found very good correspondence. CONCLUSION: The visual read and SKM methods, applied together, may optimize the identification of early Aß deposition. These methods have the potential to provide a standard approach to the detection of PiB-positivity that is generalizable across centers.

A new measure of caregiver burden in Alzheimer's disease: the caregiver-perceived burden questionnaire.

OBJECTIVE: To validate the Caregiver-Perceived Burden Questionnaire (CPBQ) and report its psychometric properties. METHODS: The CPBQ was administered to caregivers of patients with moderate-to-severe AD in a double-blind randomized trial comparing extended-release memantine to placebo (n = 676). Measurement properties were analyzed using factor analysis, classical test theory, and Rasch analysis. RESULTS: Two subscales were identified: the Caregivers' Assessment of the Patient (CAP) and the Caregivers' Assessment of Themselves (CAT). The reliability was .89 (CAP) and .83 (CAT). The CAP scores were significantly correlated (r > .3) with scores from the Severe Impairment Battery (SIB) and the Neuropsychiatric Inventory (NPI). The CAT scores were significantly correlated with NPI scores. The CAT discriminated among patients by clinician-rated severity and significantly differentiated between responders and nonresponders. CONCLUSION: The CPBQ appears to be a reliable, valid, and responsive measure that enables linking caregiver's perceptions about burden and patient function in patients with moderate-to-severe AD.

Association between Cognitive Decline in Older Adults and Use of Primary Care Physician Services in Pennsylvania.

OBJECTIVE: To assess the relationship between cognitive decline of older patients (≥ 65 y) and use of primary care physician (PCP) services over 24 months. DESIGN: Retrospective analysis of prospectively collected data from a cluster randomized trial that took place from 2006-2010 and investigated the relationship between formal neuropsychological evaluation and patient outcomes in primary care. SETTING: Twenty-four PCPs in 11 practices in southwestern Pennsylvania. Most practices were suburban and included more than 5 PCPs. PARTICIPANTS: A sample of 423 primary care patients 65 years old or older. MEASUREMENTS: The association between the number of PCP visits and a decline in cognitive status, as determined by multivariable analyses that controlled for patient-level, physician-level, and practice-level factors (eg, patient age, comorbidities, and symptoms of depression; practice location and size; PCP age and sex) and used a linear mixed model with a random intercept to adjust for clustering. RESULTS: Over a 2-year follow-up, 199 patients (47.0%) experienced a decline in cognitive status. Patients with a cognitive decline had a mean of 0.69 more PCP visits than did patients without a cognitive decline (P < .05). CONCLUSIONS: Early signs of cognitive decline may be an indicator of greater use of primary care. Given the demographic trends, more PCPs are likely to be needed to meet the increasing needs of the older population.

The greater sensitivity of elderly APOE ε4 carriers to anticholinergic medications is independent of cerebrovascular disease risk.

BACKGROUND: Recent studies found use of anticholinergic medications to be associated with greater performance decrements in older persons who carry an ε4 allele of the apolipoprotein E (APOE) gene than in those carrying only ε2 or ε3 alleles. OBJECTIVES: The present study examined whether the apparently greater behavioral toxicity of anticholinergic drugs in ε4 carriers may result from an increased risk of cerebrovascular disease, which is more common in ε4 carriers. METHODS: Cross-sectional data were available from 240 elderly community volunteers who had participated in 2 different studies of the cognitive and motor effects of normal aging. As part of these studies, information was gathered on subjects' use of anticholinergic medications (based on an inventory of medications taken within 24 hours of testing), risk of cerebrovascular disease (Framingham Stroke Risk Profile), and APOE genotype. Performance data were also available from measures of general cognitive status (Mini-Mental State Examination), executive function (Trail Making Test), mood (Geriatric Depression Scale), sleep (Pittsburgh Sleep Quality Index), and walking speed. Logistic and linear regression models were used to examine how outcomes differed between genotypes and drug use, independent of the risk of cerebrovascular disease. RESULTS: In persons with a non-ε4 genotype, anticholinergic medication use did not significantly affect any of the behavioral measures. By contrast, among ε4 carriers, those taking anticholinergic drugs performed significantly worse than did those not taking such drugs on tests of general cognitive status, executive function, mood, and sleep. Adjusting for participants' stroke risk had a minimal effect on these results. CONCLUSIONS: Anticholinergic medication use was associated with poorer performance on measures of cognition, sleep, and mood only in older persons who carried 1 or more ε4 alleles of the APOE gene; this effect did not appear to be the result of an increased risk of cerebrovascular disease.

A pilot study of the effects of internet-based cognitive stimulation on neuropsychological function in HIV disease.

PURPOSE: Mild cognitive deficits associated with HIV disease can affect activities of daily living, so interventions that reduce them may have a long-term effect on quality of life. We evaluated the feasibility of a cognitive stimulation program (CSP) to improve neuropsychological test performance in HIV disease. METHODS: Sixty volunteers (30 HIV-infected) participated. The primary outcome was the change in neuropsychological test performance as indexed by the Global Impairment Rating; secondary outcomes included mood (Brief Symptom Inventory subscales) and quality of life rating (Medical Outcomes Survey-HIV) scales. RESULTS: Fifty-two participants completed all 24 weeks of the study, and 54% of the participants in the CSP group successfully used the system via internet access from their home or other location. There was a significant interaction between usage and study visit such that the participants who used the program most frequently showed significantly greater improvements in cognitive functioning (F(3, 46.4 = 3.26, p = 0.030); none of the secondary outcomes were affected by the dose of CSP. CONCLUSIONS: We found it possible to complete an internet-based CSP in HIV-infected individuals; ease of internet access was a key component for success. Participants who used the program most showed improvements in cognitive function over the 24-week period, suggesting that a larger clinical trial of CSP may be warranted.