Neurocognitive and psychiatric symptoms following infection with COVID-19: Evidence from laboratory and population studies.

Objective: The objective of the current investigation was to examine associations between symptomatic COVID-19 history, neurocognitive function, and psychiatric symptoms using cognitive task performance, functional brain imaging, and a prospective population survey. Methods: Study 1 was a laboratory study conducted between 3 May 2022 and 16 Nov 2022 involving 120 fully vaccinated community dwelling adults between 18 and 84 years of age (Mage = 31.96 (SD = 20.71), 63.3% female). In this cross-sectional study we examined the association between symptomatic COVID-19 infection history and performance on three computer tasks assessing cognitive function (Flanker interference, delay discounting and simple reaction time) and measured oxygen saturation within the prefrontal cortex using functional near infrared spectroscopy (fNIRS). Study 2 was a 2-wave population survey undertaken between 28 September 2021 and 21 March 2022, examining the prospective relationship between symptomatic COVID-19 and self-reported symptoms of cognitive dysfunction, depressive symptoms, anxiety symptoms, and agitation at 6-month follow up. The sample (N = 2,002, M age = 37.0, SD = 10.4; 60.8% female) was collected using a quota process to ensure equal numbers of vaccinated and unvaccinated individuals. Structural equation modelling with latent variables was performed on the population-level data, evaluating the fit of the proposed mediational model of symptomatic COVID-19 to psychiatric symptoms through cognitive dysfunction. Results: Findings from Study 1 revealed significant effects of symptomatic COVID-19 history on Flanker interference and delay discounting. Effects on flanker performance were significantly stronger among older adult women (effect: 9.603, SE = 4.452, t = 2.157, p = .033), and were accompanied by task-related changes cerebral oxygenation at the right superior frontal gyrus (F (1, 143.1) = 4.729, p = .031). Additionally, those with a symptomatic COVID-19 infection history showed evidence of amplified delay discounting (coefficient = 0.4554, SE = 0.2208, t = 2.0629, p = .041). In Study 2, baseline symptomatic COVID-19 history was associated with self-reported cognitive dysfunction and a latent variable reflecting psychiatric symptoms of anxiety, depression and agitation at follow-up. Mediational analyses revealed evidence of cognitive mediation of clinically significant psychiatric outcomes: depression (indirect effect = 0.077, SE = 0.026, p = .003) and generalized anxiety (indirect effect = 0.060, SE = 0.021, p = .004). Conclusions: Converging findings from laboratory and population survey data support the conclusion that symptomatic COVID-19 infection is associated with task-related, functional imaging and self-reported indices of cognitive dysfunction as well as psychiatric symptoms. In some cases, these findings appear to be more amplified among women than men, and among older women than younger.

Do the vaccinated perform less distancing, mask wearing and hand hygiene? A test of the risk compensation hypothesis in a representative sample during the COVID-19 pandemic.

The "risk compensation hypothesis" holds that vaccinated individuals may be less motivated to protect themselves using other COVID-19 mitigation behaviors-e.g., masking, distancing and hand hygiene-given that they may perceive their infection risk to be lower. The current investigation provides an empirical test of the risk compensation hypothesis in the COVID-19 context using prospective data from the Canadian COVID-19 Experiences Survey (CCES). The survey comprised 1,958 unvaccinated and fully vaccinated individuals drawn from a representative sample, using quota sampling to ensure substantial representation of unvaccinated individuals. Two waves of data were collected 6 months apart. Findings revealed that vaccinated individuals performed COVID-19 mitigation behaviors significantly more frequently than their unvaccinated counterparts, and they also showed lower rates of attenuation as the pandemic continued. In summary, our findings do not support the risk compensation hypothesis; instead they support the notion that people adopt vaccination and other protective behaviors in parallel.

Morphology of the prefrontal cortex predicts body composition in early adolescence: cognitive mediators and environmental moderators in the ABCD Study.

Morphological features of the lateral prefrontal cortex (PFC) in late childhood and early adolescence may provide important clues as to the developmental etiology of clinical conditions such as obesity. Body composition measurements and structural brain imaging were performed on 11 226 youth at baseline (age 9 or 10 years) and follow-up (age 11 or 12 years). Baseline morphological features of the lateral PFC were examined as predictors of body composition. Findings revealed reliable associations between middle frontal gyrus volume, thickness and surface area and multiple indices of body composition. These findings were consistent across both time points and remained significant after covariate adjustment. Cortical thicknesses of the inferior frontal gyrus and lateral orbitofrontal cortex were also reliable predictors. Morphology effects on body composition were mediated by performance on a non-verbal reasoning task. Modest but reliable moderation effects were observed with respect to environmental self-regulatory demand after controlling for sex, race/ethnicity, income and methodological variables. Overall findings suggest that PFC morphology is a reliable predictor of body composition in early adolescence, as mediated through select cognitive functions and partially moderated by environmental characteristics.

Effects of prefrontal theta burst stimulation on neuronal activity and subsequent eating behavior: an interleaved rTMS and fNIRS study.

The dorsolateral prefrontal cortex (dlPFC) and dorsomedial prefrontal cortex (dmPFC) are both important nodes for self-control and decision-making but through separable processes (cognitive control vs evaluative processing). This study aimed to examine the effects of excitatory brain stimulation [intermittent theta burst stimulation (iTBS)] targeting the dlPFC and dmPFC on eating behavior. iTBS was hypothesized to decrease consumption of appetitive snack foods, via enhanced interference control for dlPFC stimulation and reduced delay discounting (DD) for dmPFC stimulation. Using a single-blinded, between-subjects design, participants (N = 43) were randomly assigned to one of three conditions: (i) iTBS targeting the left dlPFC, (ii) iTBS targeting bilateral dmPFC or (iii) sham. Participants then completed two cognitive tasks (DD and Flanker), followed by a bogus taste test. Functional near-infrared spectroscopy imaging revealed that increases in the medial prefrontal cortex activity were evident in the dmPFC stimulation group during the DD task; likewise, a neural efficiency effect was observed in the dlPFC stimulation group during the Flanker. Gender significantly moderated during the taste test, with females in the dmPFC showing paradoxical increases in food consumption compared to sham. Findings suggest that amplification of evaluative processing may facilitate eating indulgence when preponderant social cues are permissive and food is appetitive.

Brain and behavior in health communication: The Canadian COVID-19 Experiences Project.

Background: Vaccine hesitancy and inconsistent mitigation behavior performance have been significant challenges throughout the COVID-19 pandemic. In Canada, despite relatively high vaccine availability and uptake, willingness to accept booster shots and maintain mitigation behaviors in the post-acute phase of COVID-19 remain uncertain. The aim of the Canadian COVID-19 Experiences Project (CCEP) is threefold: 1) to identify social-cognitive and neurocognitive predictors of mitigation behaviors, 2) to identify optimal communication strategies to promote vaccination and mitigation behaviors, and 3) to examine brain health outcomes of SARS-CoV-2 infection and examine their longevity. Methods: The CCEP is comprised of two components: a conventional population survey (Study 1) and a functionally interconnected laboratory study (Study 2). Study 1 will involve 6 waves of data collection. Wave 1, completed between 28 September and 21 October 2021, recruited 1,958 vaccine-hesitant (49.8%) and fully vaccinated (50.2%) adults using quota sampling to ensure maximum statistical power. Measures included a variety of social cognitive (e.g., beliefs, intentions) and neurocognitive (e.g., delay discounting) measures, followed by an opportunity to view and rate a set of professionally produced COVID-19 public service announcement (PSA) videos for perceived efficacy. Study 2 employs the same survey items and PSAs but coupled with lab-based eye tracking and functional near-infrared spectroscopy (fNIRS) to directly quantify neural indicators of attention capture and self-reflection in a smaller community sample. In the final phase of the project, subjective impressions and neural indicators of PSA efficacy will be compared and used to inform recommendations for construction of COVID-19 PSAs into the post-acute phase of the pandemic. Discussion: The CCEP provides a framework for evaluating effective COVID-19 communication strategies by levering conventional population surveys and the latest eye-tracking and brain imaging metrics. The CCEP will also yield important information about the brain health impacts of SARS-CoV-2 in the general population, in relation to current and future virus variants as they emerge.

Cognitive function following SARS-CoV-2 infection in a population-representative Canadian sample.

Background: SARS-CoV-2 infection is believed to adversely affect the brain, but the degree of impact on socially relevant cognitive functioning and decision-making is not well-studied, particularly among those less vulnerable to age-related mortality. The current study sought to determine whether infection status and COVID-19 symptom severity are associated with cognitive dysfunction among young and middled-aged adults in the general population, using self-reported lapses in executive control and a standardized decision-making task. Method: The survey sample comprised 1958 adults with a mean age of 37 years (SD â€‹= â€‹10.4); 60.8% were female. Participants reported SARS-CoV-2 infection history and, among those reporting a prior infection, COVID-19 symptom severity. Primary outcomes were self-reported symptoms of cognitive dysfunction assessed via an abbreviated form of the Barkley Deficits in Executive Functioning Scale (BDEFS) and performance on a validated delay-discounting task. Results: Young and middle-aged adults with a positive SARS-CoV-2 infection history reported a significantly higher number of cognitive dysfunction symptoms (M adj  â€‹= â€‹1.89, SE â€‹= â€‹0.08, CI: 1.74, 2.04; n â€‹= â€‹175) than their non-infected counterparts (M adj  â€‹= â€‹1.63, SE â€‹= â€‹0.08, CI: 1.47,1.80; n â€‹= â€‹1599; ߠ​= â€‹0.26, p â€‹= â€‹.001). Among those infected, there was a dose-response relationship between COVID-19 symptom severity and level of cognitive dysfunction reported, with moderate (ߠ​= â€‹0.23, CI: 0.003-0.46) and very/extremely severe (ߠ​= â€‹0.69, CI: 0.22-1.16) COVID-19 symptoms being associated with significantly greater cognitive dysfunction. These effects remained reliable and of similar magnitude after controlling for demographics, vaccination status, mitigation behavior frequency, and geographic region, and after removal of those who had been intubated during hospitalization. Very similar-and comparatively larger-effects were found for the delay-discounting task, and when using only PCR confirmed SARS-CoV-2 cases. Conclusions: Positive SARS-CoV-2 infection history and moderate or higher COVID-19 symptom severity are associated with significant symptoms of cognitive dysfunction and amplified delay discounting among young and middle-aged adults with no history of medically induced coma.

Biobehavioral Aspects of the COVID-19 Pandemic: A Review.

OBJECTIVE: This review highlights the scope and significance of the coronavirus disease 2019 (COVID-19) pandemic with a focus on biobehavioral aspects and critical avenues for research. METHODS: A narrative review of the published research literature was undertaken, highlighting major empirical findings emerging during the first and second waves of the COVID-19 pandemic. RESULTS: Interactions among biological, behavioral, and societal processes were prominent across all regions of the globe during the first year of the COVID-19 emergency. Affective, cognitive, behavioral, socioeconomic, and technological factors all played a significant role in the spread of infection, response precautions, and outcomes of mitigation efforts. Affective symptoms, suicidality, and cognitive dysfunction have been widely described consequences of the infection, the economic fallout, and the necessary public health mitigation measures themselves. The impact of COVID-19 may be especially serious for those living with severe mental illness and/or chronic medical diseases, given the confluence of several adverse factors in a manner that appears to have syndemic potential. CONCLUSIONS: The COVID-19 pandemic has made clear that biological and behavioral factors interact with societal processes in the infectious disease context. Empirical research examining mechanistic pathways from infection and recovery to immunological, behavioral, and emotional outcomes is critical. Examination of how emotional and behavioral factors relate to the pandemic-both as causes and as effects-can provide valuable insights that can improve management of the current pandemic and future pandemics to come.

Quantifying Cortical Resilience in Experimental, Clinical, and Epidemiological Studies: A Conceptually Grounded Method Using Noninvasive Brain Stimulation.

OBJECTIVE: Cortical resilience can be defined as the ability of the cortex of the human brain to rebound efficiently from perturbation. This concept is important in both research and clinical practice contexts. However, no direct measure of cortical resilience exists. Inhibitory variants of repetitive transcranial magnetic stimulation, such as continuous theta burst stimulation, provide a standardized method for inducing a perturbation; when coupled with the assessment of recovery rate from the perturbation, such a paradigm might provide a standardized measure of cortical resilience. This article describes a standardized method for quantifying cortical resilience using theta burst stimulation protocols. METHODS: A descriptive overview of a method for assessing cortical resilience is presented. Links are drawn between critical facets of the resilience construct and the protocol described. RESULTS: The Cortical Challenge and Recovery Test (CCaRT) method makes use of existing stimulation parameters and cognitive testing paradigms to provide a flexible and conceptually meaningful measure of cortical resilience. CONCLUSIONS: The CCaRT paradigm is potentially useful in research and contexts where cortical resilience is to be measured. The CCaRT paradigm has applicability to epidemiological studies and laboratory experimentation as well as diagnostic practice and clinical trial outcome measures.