Abstract Objective The risks and factors contributing to major depressive episodes in HIV infection remain unclear. This 2-year prospective study compared cumulative rates and predictors of a major ...depressive episode in HIV-infected (HIV+) men ( N = 297) and uninfected (HIV−) risk-group controls ( N = 90). Methods By design participants at entry were without current major depression, substance dependence or major anxiety disorder. Standardized neuromedical, neuropsychological, neuroimaging, life events, and psychiatric assessments (Structured Clinical Interview for DSM III-R) were conducted semi-annually for those with AIDS, and annually for all others. Results Lifetime prevalence of major depression or other psychiatric disorder did not differ at baseline between HIV+ men and controls. On a two-year follow-up those with symptomatic HIV disease were significantly more likely to experience a major depressive episode than were asymptomatic HIV+ individuals and HIV-controls ( p < 0.05). Episodes were as likely to be first onset as recurrent depression. After baseline disease stage and medical variables associated with HIV infection were controlled, a lifetime history of major depression, or of lifetime psychiatric comorbidity (two or more psychiatric disorders), predicted subsequent major depressive episode ( p < 0.05). Neither HIV disease progression during follow-up, nor the baseline presence of neurocognitive impairment, clinical brain imaging abnormality, or marked life adversity predicted a later major depressive episode. Limitations Research cohort of men examined before era of widespread use of advanced anti-HIV therapies. Conclusions Symptomatic HIV disease, but not HIV infection itself, increases intermediate-term risk of major depression. Prior psychiatric history most strongly predicted future vulnerability.
BACKGROUND:Mitochondrial DNA (mtDNA) copy number varies by cell type and energy demands. Blood mtDNA copy number has been associated with neurocognitive function in persons without HIV. Low mtDNA ...copy number may indicate disordered mtDNA replication; high copy number may reflect a response to mitochondrial dysfunction. We hypothesized that blood mtDNA copy number estimated from genome-wide genotyping data is related to neurocognitive impairment (NCI) in persons with HIV.
METHODS:In the CNS HIV Antiretroviral Therapy Effects Research (CHARTER) study, peripheral blood mtDNA copy number was obtained from genome-wide genotyping data as a ratio of mtDNA single-nucleotide polymorphism probe intensities relative to nuclear DNA single-nucleotide polymorphisms. In a multivariable regression model, associations between mtDNA copy number and demographics, blood cell counts, and HIV disease and treatment characteristics were tested. Associations of mtDNA copy number with the global deficit score (GDS), GDS-defined NCI (GDS ≥ 0.5), and HIV-associated neurocognitive disorder (HAND) diagnosis were tested by logistic regression, adjusting for potential confounders.
RESULTS:Among 1010 CHARTER participants, lower mtDNA copy number was associated with longer antiretroviral therapy duration (P < 0.001), but not with d-drug exposure (P = 0.85). mtDNA copy number was also associated with GDS (P = 0.007), GDS-defined NCI (P < 0.001), and HAND (P = 0.002). In all analyses, higher mtDNA copy number was associated with poorer cognitive performance.
CONCLUSIONS:Higher mtDNA copy number estimated from peripheral blood genotyping was associated with worse neurocognitive performance in adults with HIV. These results suggest a connection between peripheral blood mtDNA and NCI, and may represent increased mtDNA replication in response to mitochondrial dysfunction.
• We evaluated two intelligent tutoring systems in a summer school program.• We examined test scores among repeated measures of arithmetic and algebra.• Test scores increased over time and produced ...large pre/post effect sizes.• Test scores between the two systems were not significantly different.
This study evaluated 2 off-the-shelf, computer-based, mathematics intelligent-tutoring systems that provide instruction in algebra during a remedial mathematics summer program. The majority of the enrolled high school students failed to pass algebra in the previous semester. Students were randomly assigned in approximately equal proportions to work with the Carnegie Learning Algebra Cognitive Tutor or the ALEKS Algebra Course. Using the tutoring system exclusively, the students completed a 4-h-a-day, 14-day summer school high school algebra class for credit. The results revealed that both tutoring systems produced statistically and practically meaningful learning gains on measures of arithmetic and algebra knowledge.
Background. The Veterans Aging Cohort Study (VACS) Index, a composite marker of disease severity among human immunodeficiency virus (HIV)-infected persons, has been associated with concurrent risk ...for neurocognitive impairment (NCI). The present study examined whether the VACS Index predicts longitudinal neurocognitive change. Methods. Participants included 655 HIV-infected persons followed for up to 6 years in cohort studies at the University of California, San Diego, HIV Neurobehavioral Research Program (mean age at baseline, 42.5 years; 83% male; 60% white; AIDS in 67%; median current CD4+ T-cell count, 346/μL; 61% receiving antiretroviral therapy). The VACS Index was calculated through standard methods. Participants completed a comprehensive neurocognitive battery. Neurocognitive status was plotted over time using demographically and practice-adjusted global and domain T scores. NCI was defined by global deficit scores derived from T scores. Results. Baseline VACS Index scores were not predictive of changes in global T scores during the follow-up period (P = .14). However, in time-dependent analyses adjusting for covariates, higher VACS Index scores were significantly associated with worse global and domain neurocognitive performance (Ps < .01), as well as increased risk for developing NCI in a subgroup of persons who were neurocognitively normal at baseline (hazard ratio HR, 1.17; P < .001). We categorized VACS Index scores by quartiles and found that the upper-quartile group was significantly more likely to develop NCI than the lower quartile (HR, 2.16; P < .01) and middle groups (HR, 1.76; P < .01). Conclusions. Changes in VACS Index scores correspond to changes in neurocognitive function. HIV-infected persons with high VACS Index scores are at increased risk for decline and incident NCI. The VACS Index shows promise as a tool for identifying HIV-infected persons at risk for NCI.
Anemia has been linked to adverse human immunodeficiency virus (HIV) outcomes, including dementia, in the era before highly active antiretroviral therapy (HAART). Milder forms of HIV-associated ...neurocognitive disorder (HAND) remain common in HIV-infected persons, despite HAART, but whether anemia predicts HAND in the HAART era is unknown.
We evaluated time-dependent associations of anemia and cross-sectional associations of red blood cell indices with neurocognitive impairment in a multicenter, HAART-era HIV cohort study (N = 1261), adjusting for potential confounders, including age, nadir CD4(+) T-cell count, zidovudine use, and comorbid conditions. Subjects underwent comprehensive neuropsychiatric and neuromedical assessments.
HAND, defined according to standardized criteria, occurred in 595 subjects (47%) at entry. Mean corpuscular volume and mean corpuscular hemoglobin were positively associated with the global deficit score, a continuous measure of neurocognitive impairment (both P < .01), as well as with all HAND, milder forms of HAND, and HIV-associated dementia in multivariable analyses (all P < .05). Anemia independently predicted development of HAND during a median follow-up of 72 months (adjusted hazard ratio, 1.55; P < .01).
Anemia and red blood cell indices predict HAND in the HAART era and may contribute to risk assessment. Future studies should address whether treating anemia may help to prevent HAND or improve cognitive function in HIV-infected persons.
The effects of aging on the presentation of HIV-associated neurocognitive disorders are largely unknown. In a cross-sectional observational study, we compared the neuropsychological profiles of 67 ...HIV-positive patients aged at least 50 years with those of 52 participants aged 35 years or less.
Participants received neuropsychological, psychiatric and neuromedical evaluations. Raw neuropsychological test scores were converted to demographically corrected T-scores; all were corrected for the effects of normal aging. Clinical ratings of impairment were assigned to the neuropsychological results.
The two groups did not differ statistically with respect to demographic variables, percentage with AIDS, or CD4 cell counts. The 'younger' group had higher viral burdens in plasma and cerebrospinal fluid (CSF), and fewer were receiving antiretroviral treatment. The proportion of neuropsychologically impaired subjects in the 'older' group was slightly greater than in the younger group, and the older group tended to have higher rates of impairment across most ability domains. When group differences in CSF viral load were modeled statistically, both viral burden and age were significant predictors of neuropsychological impairment, together with a significant interaction between viral burden and age. Older individuals with detectable virus in CSF had twice the prevalence of neuropsychological impairment of those with undetectable levels. Among younger individuals, this proportion was not affected by viral load. Lifetime major depression, substance use disorder, and current depression symptoms were not associated with neuropsychological impairment.
Although further studies with larger and older samples are needed, this investigation suggests that older adults may be at greater risk of HIV-related neurocognitive dysfunction.
OBJECTIVE:To investigate the effect of hepatitis C virus (HCV) on neurocognitive performance in chronically HIV-infected patients enrolled in the CNS HIV Antiretroviral Therapy Effects Research ...(CHARTER) study.
METHODS:A total of 1,582 participants in CHARTER who were tested for HCV antibody underwent neurocognitive testing; serum HCV RNA was available for 346 seropositive patients. Neurocognitive performance was compared in 408 HCV-seropositive and 1,174 HCV-seronegative participants and in a subset of 160 seropositive and 707 seronegative participants without serious comorbid neurologic conditions that might impair neurocognitive performance, using linear regression and taking into account HIV-associated and demographic factors (including IV drug use) and liver function.
RESULTS:Neurocognitive performance characterized by global deficit scores and the proportion of individuals who were impaired were the same in the HCV-seropositive and HCV-seronegative groups. In univariable analyses in the entire sample, only verbal domain scores showed small statistically different superior performance in the HCV+ group that was not evident in multivariable analysis. In the subgroup without significant comorbidities, scores in all 7 domains of neurocognitive functioning did not differ by HCV serostatus. Among the HCV-seropositive participants, there was no association between neurocognitive performance and serum HCV RNA concentration.
CONCLUSION:In HIV-infected patients, HCV coinfection does not contribute to neurocognitive impairment, at least in the absence of substantial HCV-associated liver damage, which was not evident in our cohort.
This pilot study examined rates of major depression and suicidality and their associations with daily functioning in HIV infected (HIV+) and uninfected (HIV−) persons in China.
HIV+ participants (
N
...=
28) and demographically matched HIV− controls (
N
=
23) completed the Chinese Composite International Diagnostic Interview to determine lifetime rates of major depressive disorder (MDD) and suicidality. Current mood and suicidal ideation were assessed with the Beck Depression Inventory-I. The impact of depression and HIV infection on daily functioning was measured by an Activity of Daily Living questionnaire.
Mean duration of known HIV+ status was 2 years. Almost 79% (
n
=
22) of HIV+ but just 4% (
n
=
1) of HIV− groups reported lifetime major depression. Of the 22 HIV+ individuals with lifetime MDD, only one had onset before learning of HIV status. The remainder developed MDD within 6 months after testing HIV positive. In those HIV+ subjects who met MDD criteria after HIV diagnosis, only two (9%) had received depression treatment, yet four (18%) had persisting active suicidal thoughts. Depression and HIV+ status independently predicted worse daily functioning.
Representativeness is limited in this small sample of convenience.
This preliminary study presents evidence of high rates of major depression and suicidality in HIV-infected persons in China. Despite this, few had sought mental health assistance, suggesting a need to increase awareness of psychiatric comorbidity and access to mental health services.
Research has shown that it is effective to combine example study and problem solving in the initial acquisition of cognitive skills. Present methods for combining these learning modes are static, ...however, and do not support a transition from example study in early stages of skill acquisition to later problem solving. Against this background, the authors proposed a successive integration of problem-solving elements into example study until the learners solved problems on their own (i.e., complete example increasingly more incomplete examples problem to-be-solved). The authors tested the effectiveness of such a fading procedure against the traditional method of using example-problem pairs. In a field experiment and in 2 more controlled laboratory experiments, the authors found that (a) the fading procedure fosters learning, at least when near transfer performance is considered; (b) the number of problem-solving errors during learning plays a role in mediating this effect; and (c) it is more favorable to fade out worked-out solution steps in a backward manner (omitting the last solution steps first) as compared with a forward manner (omitting the first solution steps first). (Verlag).
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NMLJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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