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Polygenic burden and its association with baseline cognitive function and postoperative cognitive outcome in temporal lobe epilepsy.

OBJECTIVE: Demographic and disease factors are associated with cognitive deficits and postoperative cognitive declines in adults with pharmacoresistant temporal lobe epilepsy (TLE), but the role of genetic factors in cognition in TLE is not well understood. Polygenic scores (PGS) for neurological and neuropsychiatric disorders and IQ have been associated with cognition in patient and healthy populations. In this exploratory study, we examined the relationship between PGS for Alzheimer's disease (AD), depression, and IQ and cognitive outcomes in adults with TLE. METHODS: 202 adults with pharmacoresistant TLE had genotyping and completed neuropsychological evaluations as part of a presurgical work-up. A subset (n = 116) underwent temporal lobe resection and returned for postoperative cognitive testing. Logistic regression was used to determine if PGS for AD, depression, and IQ predicted baseline domain-specific cognitive function and cognitive phenotypes as well as postoperative language and memory decline. RESULTS: No significant findings survived correction for multiple comparisons. Prior to correction, higher PGS for AD and depression (i.e., increased genetic risk for the disorder), but lower PGS for IQ (i.e., decreased genetic likelihood of high IQ) appeared possibly associated with baseline cognitive impairment in TLE. In comparison, higher PGS for AD and IQ appeared as possible risk factors for cognitive decline following temporal lobectomy, while the possible relationship between PGS for depression and post-operative cognitive outcome was mixed. SIGNIFICANCE: We did not observe any relationships of large effect between PGS and cognitive function or postsurgical outcome; however, results highlight several promising trends in the data that warrant future investigation in larger samples better powered to detect small genetic effects.

Adult

Effects of Exergame Balance Training with Variable Cognitive Motor Challenges on Serum BDNF, p-tau181, and Cognitive Functions in Adults with Mild Cognitive Impairment: A Randomized Trial.

INTRODUCTION: Cognitive-motor exergame balance training may increase attentional demands and neuronal processing, potentially affecting serum levels of brain-derived neurotrophic factor (BDNF), A&#x3b2;1-42, and p-tau181, as well as train cognitive abilities in adults with mild cognitive impairment (MCI). This study aimed to compare the effects of exergame balance training of mild, moderate, high-difficulty, and Wii Fit&#x2122; groups on blood serum levels of BDNF, A&#x3b2;1-42, p-tau181, and cognition function in adults with MCI. METHODS: In this four-arm, parallel group randomized clinical trial, 97 adults with MCI were randomly assigned to exergame balance training groups of mild, moderate, high-difficulty, and Wii Fit exergame as a control group. All participants received 40 min/session, 3 times/week for 8 weeks. Assessment of serum levels of p-tau181, A&#x3b2;1-42, BDNF, and cognitive functions was conducted at baseline, after weeks 4 and 8. A mixed-model analysis of covariance was used, with post-baseline measurements (weeks 4 and 8) specified as the within-subject factor and the corresponding baseline value entered as a covariate to adjust for initial between-group variability. RESULTS: A significant group &#xd7; time interaction was found for BDNF, F(3,92) = 6.413, P = 0.017, &#x3b7;p2 = 0.181; p-tau181, F(3,92) = 4.640, P = 0.040, &#x3b7;p2 = 0.138; attention, F(3,92) = 4.171, P = 0.045, &#x3b7;p2 = 0.057; abstraction, F(3,92) = 4.263, P = 0.043, &#x3b7;p2 = 0.058; and visuospatial skills, F(3,92) = 6.931, P < 0.001, &#x3b7;p2 = 0.234. CONCLUSION: Cognitive-motor challenge-based exergame balance training was associated with an increase in serum BDNF, a reduction in p-tau181. In contrast, the A&#x3b2;1-42 levels remained stable. These changes were accompanied by improvement in selective cognitive functions (attention, abstraction, and visuospatial skills) in individuals with MCI. Greater effects were observed in moderate and high-difficulty groups, suggesting the importance of intervention intensity in promoting cognitive and neurobiological outcomes in MCI.

Humans

Genetic Association of the Transcriptome and Immunoglobulin G N-glycome with Cognitive Function.

OBJECTIVE: Immunoglobulin G (IgG) N-glycosylation is associated with mild cognitive impairment through the regulation of inflammatory balance; however, the underlying mechanisms remain unclear. METHODS: Our study utilized a post-genome-wide association studies (GWAS) method that integrated GWAS data for cognitive function with gene expression quantitative trait loci (eQTL), protein QTL (pQTL), and IgG N-glycan-QTL data. RESULTS: Mendelian randomization (MR) analyses suggested bidirectional causalities between glycan peaks (GPs) and cognitive function, with GP7, GP12, and GP19 showing a causal effect on cognitive function, while cognitive function conversely showed a causal effect on GP1 and GP8. Two proteins and 10 genes were implicated in the regulation of IgG N-glycosylation. Furthermore, multivariable MR results suggested complex causalities between genes/proteins and IgG N-glycans, which jointly promote or independently affect cognitive function. CONCLUSION: Our study reveals a novel mechanism by which genes, proteins, and modified IgG N-glycans converge to pathologically affect cognitive function.

Immunoglobulin G

Acute COVID-19 severity and impaired cognitive function up to 32&#xa0;months after diagnosis: an observational study.

BACKGROUND: Cognitive dysfunction ("brain fog") is a commonly reported post-COVID-19 symptom. Leveraging data from five general population cohorts across four European countries (Estonia, Iceland, Norway, and Sweden), we assessed long-term prevalence of impaired subjective cognitive function among individuals diagnosed with COVID-19 by acute illness severity. METHODS: The included cohorts consisted of adult participants recruited from March 2020 and followed with self-report measures of cognitive function and past COVID-19 infection (except one cohort consisting of clinically confirmed COVID-19 cases) through February 2023. In a cross-sectional analysis we contrasted the prevalence of impaired cognitive function among individuals with and without a COVID-19 diagnosis, overall and by illness severity up to 32&#xa0;months post-diagnosis. We adjusted for age, gender, education, relationship status, binge drinking, body mass index, previous psychiatric diagnosis, number of chronic medical conditions, and response period. In a longitudinal analysis, we assessed potential changes in cognitive function scores before and after COVID-19 diagnosis. RESULTS: The study population consisted of 153,841 participants (71% women), with 31,359 (20.4%) reporting a positive COVID-19 test. Overall, a COVID-19 diagnosis was not statistically significantly associated with increased prevalence ratio (PR) of impaired cognitive function (PR 1.30 [95% CI: 0.98-1.71]). Individuals bedridden due to COVID-19 for 1-6&#xa0;days (PR 1.38 [95% CI 0.96-1.99]) or&#x2009;&#x2265;&#x2009;7&#xa0;days (2.59 [1.55-4.33]) had higher prevalence of impaired cognitive function compared to those never diagnosed, while individuals never bedridden had a lower prevalence to those never diagnosed with COVID-19 (0.89 [0.80-1.00]). These findings were corroborated in the longitudinal analysis where a pre- to post diagnosis decline in cognitive function was observed among individuals bedridden due to COVID-19 (p&#x2009;<&#x2009;0.0001). CONCLUSIONS: The data indicates that a severe COVID-19 acute illness course is associated with impaired cognitive function up to 18-32&#xa0;months after COVID-19 diagnosis.

Adult

Extended Long-Term Effects of Cognitive and Aerobic Training on Cognitive Function in Patients With Stress-Related Exhaustion Disorder: A 4.5-Year Follow-Up of a Randomized Controlled Trial.

Stress-related conditions like clinical burnout and exhaustion disorder (ED) are associated with enduring cognitive problems. We have previously demonstrated that the addition of computerised cognitive training (CCT) and aerobic training (AT) to a multimodal rehabilitation programme (MMR) yielded greater improvements in cognitive function compared to MMR alone in patients with ED. These effects were maintained at the 1-year follow-up for CCT, but not for AT. Building on these findings, the present study examined the extended long-term effects of CCT and AT on cognitive function, psychological health, and work ability, 4.5&#xa0;years after the interventions. Participants were recruited from a stress-rehabilitation clinic and 56 of the initial 132 participants returned for the 4.5-year follow-up. Assessments were conducted before (T1), immediately after (T2), 1-year after (T3) and 4.5-years after (T4) the interventions. Mixed model analyses assessed changes in the intervention groups relative to the control group from T1 to T4, with follow-up comparisons examining within-group stability of outcomes between T3 to T4. The primary outcome was cognitive performance on a global cognitive score. Secondary outcomes included domain-specific cognitive functioning, self-reported cognitive function, psychological health (burnout, depression, anxiety, and fatigue), and work ability. The analysis revealed sustained long-term effects on the global cognitive score, a trained updating task and episodic memory in the CCT group, with stable performance between one- and 4.5-year follow-up. The addition of AT did not yield any extended long-term effects on cognitive performance. Both groups showed extended long-term improvements in self-reported memory problems, although findings were mixed. Extended long-term improvements were observed on burnout for both groups, with additional effects on anxiety and work ability in the AT group. Notably, these effects were not present at the 1-year follow-up and are more plausibly explained by selective attrition rather than a delayed intervention effect. In conclusion, the result indicates that cognitive interventions such as CCT can have lasting positive effects on cognitive function in patients with ED, whereas the long-term psychological effects should be interpreted with caution. TRIAL REGISTRATION: ClinicalTrials.gov: NCT0073772.

Adult

The genetic overlap between schizophrenia and major depression with cognitive function.

This study aimed to systematically dissect the shared genetic basis of schizophrenia (SCZ) and major depression (MD) with cognitive function. To investigate this, we integrated large-scale genome-wide association studies (GWAS) summary statistics for SCZ (N&#x2009;=&#x2009;175,799, [cases, 74,776; controls, 101,023]), MD (N&#x2009;=&#x2009;2,622,273 [cases, 550,355; controls, 2,071,918]) and four cognitive traits (reaction time, N&#x2009;=&#x2009;330,069; memory, N&#x2009;=&#x2009;112,067; verbal-numerical reasoning, N&#x2009;=&#x2009;36,035; educational attainment, N&#x2009;=&#x2009;111,114). Linkage disequilibrium (LD) score regression analysis revealed that SCZ showed significant negative genetic correlations with reaction time, memory, and verbal-numerical reasoning. MD showed negative genetic correlations with memory, verbal-numerical reasoning, and educational attainment. Bayesian colocalization analysis identified seven genomic regions with strong or supportive evidence between SCZ and cognitive function, and two genomic regions with supportive evidence between MD and cognitive function. Gene mapping and over representation analysis (ORA) indicated that SCZ-associated genes were primarily involved in pathways related to transport processes, and MD-associated genes were significantly enriched in pathways related to neural development. Through genetic correlation and colocalization analysis, this study elucidates the genetic overlap between SCZ and MD with cognitive function, providing a new perspective for related research.

Journal Article

Social support and cognitive function in postmenopausal women.

OBJECTIVE: An active social lifestyle may protect against cognitive decline in older adults, but few studies have examined specific social support dimensions in relation to specific cognitive domains. This study examines associations between social support dimensions and cognitive function in older women. METHODS: The Early versus Late Intervention Trial with Estradiol (ELITE) was a randomized, double-blinded, placebo-controlled trial of oral 17&#x3b2;-estradiol versus placebo in postmenopausal women, designed primarily to evaluate the timing hypothesis on atherosclerosis progression and cognitive decline; the present analysis is a secondary, hypothesis-generating examination of the psychosocial substudy data (2009-2012). A total of 448 women completed psychosocial assessments every 6 months. Cognitive function was assessed at baseline, 2.5, and 5 years using composite scores for executive function, verbal memory, visual memory, and global cognition derived from 14 standardized tests. Perceived social support was assessed using the Medical Outcomes Study-Social Support Survey (MOS-SSS; 0-100 scale). Paired cognitive-psychosocial assessments were analyzed using linear mixed-effects models adjusted for age, marital status, blood pressure medication, BMI, education, income, race, and randomized treatment (hormone therapy or placebo). RESULTS: A total of 298 women (mean age 60.3&#xa0;y) provided 322 paired visits. Positive associations were observed between instrumental social support and visual memory (&#x3b2;(SE)=0.0044(0.0022), 95% CI: -0.00002 to 0.0088, P=0.051) and between positive social interaction and global cognition (&#x3b2;(SE)=0.0092(0.0046), 95% CI: 0.0001-0.0182, P=0.047). In age-stratified analyses, the positive social interaction-global cognition association was significant among women <65 years (P=0.042) but not women &#x2265;65 years (P=0.34). No association survived false discovery rate (FDR) correction for multiple comparisons. CONCLUSIONS: In this sample of healthy middle- to older-aged women, no association between specific dimensions of social support and cognitive domains was statistically significant after correction for multiple comparisons. These hypothesis-generating findings suggest any association is modest at best and warrant confirmation in studies designed specifically for this question.

Cognitive function

The effect of regular exercise on cognitive functioning and personality.

The effect of regular exercise on cognitive functioning and personality was investigated in 32 subjects representing 4 discrete groups based on sex and age. Before and after a 10 week exercise programme of jogging, calisthenics, and recreational activities, a test battery was administered to assess functioning in a number of domains: intelligence (WAIS Digit Symbol and Block Design); brain function (Trail-Making); speed of performance (Crossing-Off); memory and learning (WMS Visual Reproduction and Associate Learning); morale and life satisfaction (Life Satisfaction and Control Ratings); anxiety (MAACL); and depression (MAACL). Improvement was observed on several physiological parameters. ANOVA revealed significant sex and age differences on Digit Symbol and Block Design and age differences on Trail-Making, Crossing-Off, Associate Learning, and anxiety. Regardless of sex and age, significant improvement in performance was observed from pre to post-test on Digit Symbol, Block Design, Trail-Making, Crossing-Off, and on Associate Learning. In addition, an increase on health status rating (p less than .01) and decrease in anxiety were observed from pre to post-test. These data illustrate beneficial effects of exercise on certain measures of cognitive functioning and personality.

Adult

Comparing trajectories of cognitive functioning in treatment-resistant and non-resistant depression: a multicentre linear mixed-effects analysis.

BACKGROUND: Impaired cognitive functioning is a severe symptom in major depressive disorder (MDD). Recent evidence suggests it may be a central characteristic in its treatment resistant form (TRD), potentially constituting a clinical marker for treatment resistance and a target amenable to intervention. To date, cognitive functioning in TRD remains poorly understood and longitudinal investigations are scarce. METHODS: This observational prospective cohort study, including 320 patients diagnosed with MDD from the multicentre PROMPT study, examined differences in cognitive functioning between 118 TRD and 202 non-TRD patients over a period of twelve weeks in a real-world setting, using linear mixed modelling. Patients that failed to respond to at least two prior antidepressants trials at baseline were classified as TRD. RESULTS: TRD patients showed significantly poorer baseline performances than non-TRD patients in attention/processing speed (&#x3b2;&#xa0;=&#xa0;-0.45; 95%CI[-0.70, -0.19]; FDR-p&#xa0;=&#xa0;0.003) and verbal memory (&#x3b2;&#xa0;=&#xa0;-0.45; 95%CI[-0.72, -0.18]; FDR-p&#xa0;=&#xa0;0.003). Significant time &#xd7; group interactions were observed in motor speed and verbal fluency tasks. Post-hoc-analyses revealed stagnation in TRD patients and significant improvement in non-TRD patients. Across all other tasks improvement was observed in both groups, and random effects showed large heterogeneity between patients, indicating notable individual differences in cognitive performances. CONCLUSIONS: The results suggest distinct recovery patters between non-TRD and TRD patients, and diminished functioning in TRD patients at the domain level. However, intact and diminished performances likely occur in both groups, warranting further investigation of cognitive heterogeneity. These short-term findings highlight the need for more comprehensive longitudinal research on cognition in TRD.

Humans

Association between pulse pressure and markers of cognitive function: a systematic review and meta-analysis.

Our aim was to systematically review and meta-analyse evidence on the association between pulse pressure (PP) and cognitive function using PubMed, PsycInfo, Embase and Scopus (inception-July 2025) publication databases. Studies were included if they reported an association between PP and cognitive function and summarized narratively and by performing fixed-effects meta-analysis. The search identified 4171 publications with 43 studies meeting inclusion criteria. Domains assessed included global cognition, memory, language, attention, executive function, processing speed and visuospatial ability. Meta-analysis suggests a positive association between PP and global cognition, and a negative association with memory in both cross-sectional and longitudinal studies with inconsistent findings from narratively summarized studies. Processing speed, executive function and language negatively associated with PP in cross-sectional studies with limited evidence provided by longitudinal studies or narratively summarized studies. There was limited evidence of an association with attention and visuospatial ability.

Humans

Effects of six weeks of guanidinoacetic acid supplementation with and without creatine monohydrate on cognitive function and markers of health in healthy adults.

BACKGROUND: Guanidinoacetic acid (GAA) supplementation has been reported to increase brain creatine content more effectively than creatine monohydrate (CrM). However, the effects on cognitive function are unclear. PURPOSE: The purpose of this proof-of-concept exploratory clinical trial was to determine whether GAA supplementation with and without CrM affects cognitive function and/or markers of health. METHODS: In a double-blind, randomized, and counterbalanced manner, 58 healthy and active adults (33 females, 35.5&#x2009;&#xb1;&#x2009;14 years, 76.2&#x2009;&#xb1;&#x2009;14 kg) ingested a PLA (PLA, 2 &#xd7; 6 g/d maltodextrin), GAA (2 &#xd7; 1 g/d)&#x2009;+&#x2009;PLA (2 &#xd7; 5 g/d), or GAA (2 &#xd7; 1 g/d)&#x2009;+&#x2009;CrM (2 &#xd7; 5 g/d) for six weeks. The participants donated fasting blood samples and completed a battery of tests and questionnaires assessing various aspects of function, mood, stress, sleep quality, and markers of health at baseline and after six weeks of supplementation. Data were analyzed using General Linear Model (GLM) multivariate and univariate with repeated measures, and mean changes from baseline with 95% confidence intervals, and Chi-squared analysis, and considered significant when the probability of error was 0.05 or less, and approaching significance (p&#x2009;>&#x2009;0.05-p&#x2009;<&#x2009;0.10). RESULTS: GAA supplementation tended to improve overall reaction time (-241.8&#x2009;ms [-533, 50], p&#x2009;=&#x2009;0.10) while significant interaction effects were observed in overall reaction time (p&#x2009;=&#x2009;0.031-330 ms [-629, -31]) and YES reaction time (-290&#x2009;ms [-484, -96], p&#x2009;=&#x2009;0.004) while recalled correct reaction time (-178&#x2009;ms [-374, 21], p&#x2009;=&#x2009;0.078) and recalled correct YES (7.4 % [-1, 15.8], p&#x2009;=&#x2009;0.084) approached significance compared to PLA. Limited to no effects were observed on the Delayed Picture Recognition Task Test, Digit Vigilance Task Test, Corsi Block Task Test, or Stroop Color-Word Task Test. The amount of time engaged in moderate physical activity was significantly greater (p&#x2009;<&#x2009;0.05) in the GAA group compared to PLA. Participants in the GAA group reported a lower frequency of controlling irritations (p&#x2009;=&#x2009;0.036), and feeling like difficulties are mounting (p&#x2009;=&#x2009;0.053) on the Perceived Stress Scale. Some positive and potentially undesirable effects were observed in sleep quality assessments. The quality of life assessment revealed that participants in the GAA group reported less frequent feelings of being worn out (p&#x2009;=&#x2009;0.068) and that their health was excellent (p&#x2009;=&#x2009;0.092) while those in the GAA&#x2009;+&#x2009;CrM group reported more frequent limitations when bending, kneeling, or stooping (p&#x2009;=&#x2009;0.053), more often feeling full of life (p&#x2009;=&#x2009;0.081), and less frequency in feeling downhearted and depressed (p&#x2009;=&#x2009;0.066). No clinically meaningful changes were observed in blood markers or self-reported side effects among the groups. CONCLUSION: Dietary supplementation with GAA (2 g/d) and the combination of CrM (10 g/d&#x2009;+&#x2009;GAA 2 g/d) for six weeks improved delayed verbal episodic recognition memory and retrieval speed and some measures of perceived stress, sleep quality, and quality of life. However, most cognitive tests were not affected, particularly when comparing the GAA to the PLA group; there were some inconsistencies in the findings, and several differences only approached significance. Additional research is needed before conclusions can be drawn. Clinical trial registration: ISRCTN68542582.

Humans

Role of Polygenic Risk Scores in Predicting Cognitive Functioning after Mild Traumatic Brain Injury: A TRACK-TBI Study.

Patients with traumatic brain injury (TBI) and Glasgow Coma Scale scores of 13-15 (historically called mild TBI [mTBI]) commonly experience changes in cognitive functioning, including processing speed, memory, and executive functioning. In a prospective sample (N = 523) of individuals of European descent who had been treated in a U.S. level 1 trauma center for mTBI, we examined the prognostic value of four polygenic risk scores (PRS) for cognitive outcomes at 6-months postinjury. To estimate the impact of mTBI on cognition, primary cognitive outcomes were scaled as z-scores reflecting changes in performance relative to predicted preinjury performance. The PRS examined were previously developed and validated to predict cognition-related outcomes of educational attainment (Education-PRS), intelligence (Intelligence-PRS), and Alzheimer's disease (AD-mild traumatic brain injury (APOE)-PRS and AD + APOE-PRS). Both the Education-PRS and Intelligence-PRS displayed bivariate associations with all four cognitive outcomes (&#x3b2; = 0.19-0.32), whereas neither Alzheimer's disease PRS was significantly associated with any outcome. After controlling for other factors known to predict cognitive outcomes of TBI (e.g., sex, education, mTBI severity defined by a combination of Glasgow Coma Scale scores and the presence/absence of acute intracranial findings on clinical neuroimaging), the Education-PRS and Intelligence-PRS remained independently predictive of verbal episodic memory (&#x3b2; = 0.10-0.16), whereas their associations with processing speed and executive functioning were mostly nonsignificant and were mediated through educational attainment. Looking across primary z-score and secondary raw score outcomes, cognitive outcomes 6 months post-mTBI were good on average, and PRS made small independent contributions to outcome prediction. The mediation model findings may support theories of cognitive reserve, which propose that individuals with stronger preinjury cognitive processing abilities (often estimated by educational history) can better compensate for TBI. Moreover, findings indicate that PRS may contribute modestly to multivariable models predicting cognitive function after TBI.

Humans

Association between Kidney Tubular Secretory Clearance with Cognitive Function among Adults with CKD in the Systolic Blood Pressure Intervention Trial.

BACKGROUND: Persons with CKD are disproportionally affected with cognitive impairment, yet the pathophysiology linking the two conditions is unclear. Because kidney tubule secretion is essential for clearance of medications, uremic toxins, and metabolites, we hypothesized that worse tubular secretion would be associated with reduced cognitive function in CKD. METHODS: The Systolic Blood Pressure Intervention Trial tested a systolic blood pressure target <120 mmHg vs. <140 mmHg in hypertensive individuals at high cardiovascular risk. In paired blood and urine specimens from 1,937 participants with eGFR <60 ml/min/1.73m2, we measured 10 endogenous tubule-secreted metabolites and calculated a urine/plasma ratio for each, then averaged these to generate a summary secretion score. We used unadjusted and multivariable-adjusted linear regression and mixed models to evaluate cross-sectional and longitudinal associations of the secretion score with the Montreal Cognitive Assessment, Digit Symbol Coding, and Logical Memory immediate and delayed tests-measured at baseline and months 24 and 48 of follow-up. Multivariable Cox regression evaluated associations with incident probable dementia and mild cognitive impairment, adjudicated by prespecified criteria. RESULTS: Mean age was 73 &#xb1; 9 years, 41% were women, mean eGFR was 48.2 &#xb1; 11.4 ml/min/1.73m2, median albuminuria was 14.8 [7.1-48.6] mg/g. Lower secretion score was associated with a 0.06 higher adjusted logical memory delayed score (95% CI: 0.02, 0.11) but not with other cognitive tests at baseline or longitudinal cognitive decline. After a median 4.1 years of follow-up, 118 developed probable dementia and 187 developed mild cognitive impairment. Each 1-SD lower secretion score was associated with lower risk of probable dementia (HR 0.78, 95% CI: 0.63, 0.98) but not mild cognitive impairment. CONCLUSIONS: Among Systolic Blood Pressure Intervention Trial participants with CKD, lower estimated tubular secretion was not associated with worse cognition at baseline or during longitudinal follow-up.

Journal Article

Exposure to polybrominated biphenyls. Some effects on personality and cognitive functioning.

Twenty-one persons exposed to polybrominated biphenyls (PBB) were compared with hospital volunteers on a battery of tests measuring memory, motor strength and coordination, cortical-sensory perception, personality, and higher cognitive functioning. Patients exposed to PBB were selected for this study only if they had persistent medical complaints. The PBB adipose levels did not correlate with performance on any test in the battery. The two groups did differ on the Minnesota Multiphasic Personality Inventory, suggesting an adjustment reaction with depressive symptoms and somatizing defenses. Persons exposed to PBB were also impaired relative to control subjects on tests of prose recall, short-term memory, concentration, and cognitive flexibility. However these differences vanished when group differences on education and personality were statistically held constant. The selective admission criteria for this study limit the generalizability of these findings.

Adipose Tissue

Cognitive function and length of survival in elderly subjects living at home.

177 people aged 65 or over, chosen at random from larger representative samples of elderly people living at home in Newcastle upon Tyne, were given the Weschler Adult Intelligence Scale (WAIS) or a shortened form of it, and followed up for 7 years or till death. Discriminated function analysis showed that the power of the test score to predict death occurring within 2 years was not explained away by its correlations with age, sex, social class or physical disability. Exclusion of clinically diagnosed chronic brain syndromes reduced but did not abolish the relationship found to exist between test score and outcome. The ascertainment of impaired cognitive functioning has important applications in the assessment of prognosis and in the planning of care of elderly people.

Aged

Effects of quetiapine on cognitive functioning in schizophrenia: evidence for the remyelination hypothesis?

Postmortem findings, neuroimaging data, and in-vitro models suggest a decrease in number and density of oligodendrocytes is driving cognitive deficits in schizophrenia (SCZ). Second-generation antipsychotics are discussed to improve oligodendrocyte dysfunction with most conclusive evidence available for quetiapine (QET). We postulate that sustained QET treatment leads to cognitive improvement in SCZ, particularly, in tests with high demands for working memory function. We further hypothesize that these effects are moderated by polygenic factors associated with hippocampus-related brain volumes, general white matter integrity, and/or oligodendroglia-related SCZ risk. Using data of the prospective PsyCourse study, we identified 166 patients with SCZ spectrum disorder receiving QET at one or two consecutive visits plus 166 matched patients without QET. Polygenic scores were calculated for subcortical brain volumes, measures of white matter integrity, and for cell type-specific genetic SCZ risks. QET treatment was consistently associated with improved cognitive function independent of time, specifically, in tests with high, but not with low to medium working memory load. Polygenic analyses did not reveal significant moderation effects. In contrary, low genetic SCZ risk specific for genes related to human oligodendrocyte function was associated with higher cognitive performance independent from QET. While we observed improved cognitive performance under QET in high working memory tests, we did not find evidence that polygenic factors associated with hippocampus-related brain volumes, white matter integrity, or oligodendroglia-related SCZ risk moderate this association. Thus, our tentative findings do not provide evidence for the hypothesis that polygenic estimates of hippocampal remyelination capacities influence the association between QET and cognitive performance in SCZ.

Humans

Subacute and long-term changes in cognitive functioning after administration of classic psychedelics, MDMA and ketamine: A systematic review of clinical and preclinical evidence.

Psychedelic agents induce a window of heightened neuroplasticity that extends beyond acute intoxication, during which neural circuits are more amenable to change. This period may facilitate changes in cognition relevant to the treatment of psychiatric disorders. This systematic review synthesised clinical and preclinical evidence of subacute and long-term (&#x2265;1&#x202f;day) effects of classic and non-classic psychedelics on cognition. MEDLINE, EMBASE, APA PsycInfo and Web of Science were searched to identify human and animal studies investigating psychedelics and cognition (executive function, attention, decision-making). Sixty-seven (47 clinical, 20 preclinical) articles met inclusion criteria. Psilocybin demonstrated the most consistent evidence of subacute and longer-term cognitive improvement, particularly in cognitive flexibility and attention. Ketamine showed enhancement across cognitive domains, although findings were heterogeneous. LSD and DMT showed no consistent subacute changes, while MDMA was associated with transient cognitive impairments that resolved within days. Risk of bias assessments revealed selective outcome reporting, poor reporting of missing data and inadequate methodological detail, limiting the confidence of findings. Current evidence provides preliminary support for subacute changes in cognition following administration of select psychedelic agents. Cognitive improvements were more frequently seen in psychiatric populations than healthy subjects, which may reflect a remediation of existing cognitive deficit rather than enhancement above normal functioning. Adequately powered, controlled studies with standardised reporting of cognitive outcomes are required to determine the magnitude, durability and clinical relevance of psychedelic-associated cognitive change.

Hallucinogens