Brain Fog

Subjective versus objective cognition during menopause: A systematic review and meta-analysis.

Furey RT, Thomas EHX, Kulkarni J, Gurvich C · Journal of the International Neuropsychological Society : JINS · 2025 · n=5629

This systematic review and meta-analysis aimed to review existing measures of subjective cognition during menopause and to estimate the correlation between subjective and objective cognition in perimenopausal and postmenopausal women. Eligible studies reported scores for at least one subjective and objective measure of cognition for perimenopausal or postmenopausal women. EMBASE, Medline, and PsycINFO were searched for eligible studies on November 22nd 2024. The risk of bias in individual studies was evaluated using a modified QUADAS-2 form. The results of the review were summarized in narrative form. Studies that reported correlations between subjective and objective cognition were synthesized using a multilevel meta-analysis. The sample included 5629 participants over 24 studies, including 295 perimenopausal women, 5086 postmenopausal women, and 248 women across mixed peri- and post-menopausal samples. Twelve measures of subjective cognition were used across studies. Six studies we

Brain fog with long covid and chemotherapy: systematic review and meta-analysis.

Wilson JC, Liu KY, Mittelman E, Bareke P, Shleifer E, Howard R · BMJ mental health · 2025

What are the cognitive, functional and affective characteristics of brain fog in individuals with long covid and following chemotherapy, and how are these features assessed across studies? In March 2024, we conducted a systematic review and meta-analysis of peer-reviewed studies assessing cognition, function or mood in adults (≥18 years) with brain fog after COVID-19 or chemotherapy. PubMed, Embase and Web of Science were searched systematically according to eligibility criteria to March 2024, with an update in May 2025. Random-effects meta-analyses using the 'dmetar' package (V.0.0.9000) in R V.4.3.1 were performed for studies comparing individuals with and without brain fog. Bias was assessed using the National Institutes of Health Study Quality Assessment Tools. Of 3077 records screened, 65 studies met inclusion criteria: 40 investigated brain fog in long covid and 25 in chemotherapy populations. Considerable variation in assessment tools was observed. Montreal Cognitive As

Prevalence of mental health conditions and brain fog in people with long COVID: A systematic review and meta-analysis.

van der Feltz-Cornelis C, Turk F, Sweetman J, Khunti K, Gabbay M, Shepherd J · General hospital psychiatry · 2024

Long COVID can include impaired cognition ('brain fog'; a term encompassing multiple symptoms) and mental health conditions. We performed a systematic review and meta-analysis to estimate their prevalence and to explore relevant factors associated with the incidence of impaired cognition and mental health conditions. Searches were conducted in Medline and PsycINFO to cover the start of the pandemic until August 2023. Included studies reported prevalence of mental health conditions and brain fog in adults with long COVID after clinically-diagnosed or PCR-confirmed SARS-CoV-2 infection. 17 studies were included, reporting 41,249 long COVID patients. Across all timepoints (3-24 months), the combined prevalence of mental health conditions and brain fog was 20·4% (95% CI 11·1%-34·4%), being lower among those previously hospitalised than in community-managed patients(19·5 vs 29·7% respectively; p = 0·047). The odds of mental health conditions an

Intervention modalities for brain fog caused by long-COVID: systematic review of the literature.

Gorenshtein A, Liba T, Leibovitch L, Stern S, Stern Y · Neurological sciences : official journal of the Italian Neurological Society and of the Italian Society of Clinical Neurophysiology · 2024

Individuals suffering from long-COVID can present with "brain fog", which is characterized by a range of cognitive impairments, such as confusion, short-term memory loss, and difficulty concentrating. To date, several potential interventions for brain fog have been considered. Notably, no systematic review has comprehensively discussed the impact of each intervention type on brain fog symptoms. We included studies on adult (aged > 18 years) individuals with proven long- COVID brain-fog symptoms from PubMed, MEDLINE, Central, Scopus, and Embase. A search limit was set for articles published between 01/2020 and 31/12/2023. We excluded studies lacking an objective assessment of brain fog symptoms and patients with preexisting neurological diseases that affected cognition before COVID-19 infection. This review provided relevant information from 17 studies. The rehabilitation studies utilized diverse approaches, leading to a range of outcomes in terms of the effectiven

Post-COVID-19 fatigue: A systematic review.

Joli J, Buck P, Zipfel S, Stengel A · Frontiers in psychiatry · 2022 · n=629

Fatigue is recognized as one of the most commonly presented long-term complaints in individuals previously infected with SARS-CoV-2. This systematic review was performed to describe symptoms, etiology, possible risk factors related to post-COVID-19 fatigue and the therapeutic approaches used for the treatment of post-COVID-19 fatigue. For the systematic literature search the databases PubMed, Web of Science, Cochrane Library, and PsycInfo were used. All articles that met the inclusion criteria were analyzed for demographics, clinical data and treatment. Included were studies which focused on an adult population (18-65 years old); elderly patients and patients with chronic somatic diseases which can also cause fatigue were excluded. We identified 2,851, screened 2,193 and finally included 20 studies with moderate to high methodological quality, encompassing 5,629 participants. Potential risk factors for post-COVID-19 fatigue were old age, female sex, severe clinical status in the acute

What Do I Need to Know About Long-Covid-related Fatigue, Brain Fog, and Mental Health Changes?

Gross M, Lansang NM, Gopaul U, Ogawa EF, Heyn PC, Santos FH · Archives of physical medicine and rehabilitation · 2023

Clinical Practice Guidelines for Integrative Health

NCCIH

The NCCIH website provides information and research on complementary and integrative health approaches. While not a direct guideline for 'brain fog' as a standalone diagnosis, it offers resources on interventions that may address symptoms associated with brain fog, such as fatigue and cognitive impairment, from an integrative perspective.

NICE Guidelines

National Institute for Health and Care Excellence (NICE)

NICE provides national guidance and advice to improve health and social care. Users can search for guidelines related to various conditions, which may include aspects of cognitive impairment or conditions associated with 'brain fog'.

Omega-3 fatty acids, brain health and the menopause.

Minihane AM · Post reproductive health · 2025

The menopausal transition is associated with vasomotor symptoms, disrupted sleep, transient cognitive deficits and changes in mood and anxiety levels, underpinned by declining and erratic estrogen availability in the brain. Relative to other tissues the brain is enriched in the omega-3 fatty acid, docosahexaenoic (DHA), with well-defined neurophysiological roles for both eicosapentaenoic acid (EPA) and DHA. Substantial preclinical and epidemiological evidence along with accumulating randomised controlled trial (RCT) data indicates that an increase in EPA and DHA intake and status is associated with improved brain function. In this narrative review, the role of EPA and DHA in the menopausal transition (MT) is considered. The evidence, although relatively sparse, is indicative of benefit, with future RCTs needed to establish dose-response relationships and when it is most beneficial to intervene. Although research is at a relatively early stage, the MT is emerging as a critical window of

BBB breakdown caused by plasma membrane pore formation.

Wei C, Jiang W, Luo M, Shao F · Trends in cell biology · 2025

The blood-brain barrier, recently reintroduced as the blood-brain border (BBB), is a dynamic interface between the central nervous system (CNS) and the bloodstream. Disruption of the BBB exposes the CNS to peripheral pathogens and harmful substances, causing or worsening various CNS diseases. While traditional views attribute BBB failure to tight junction disruption or increased transcytosis, recent studies highlight the critical role of gasdermin D (GSDMD) pore formation in brain endothelial cells (bECs) during BBB disruption by lipopolysaccharide (LPS) or bacterial infections. This mechanism may also be involved in neurological complications like the 'brain fog' seen in long COVID. Pore formation in bECs may represent a prevalent mechanism causing BBB leakage. Investigating membrane-permeabilizing pores or channels and their effects on BBB integrity is a growing area of research. Further exploration of molecular processes that maintain, disrupt, and restore bEC membrane integrity wil

Defining brain fog across medical conditions.

Denno P, Zhao S, Husain M, Hampshire A · Trends in neurosciences · 2025

'Brain fog' is commonly reported in more than a dozen chronic diseases, but what is it? We review research across conditions which has characterised brain fog and evaluate its definitions and objective correlates. Brain fog has been used to refer to a variable set of overlapping symptoms implicating cognition, fatigue, and affect. It has been defined as a distinct symptom, a syndrome, or a nonspecific term. We consider the evidence that brain fog is a transdiagnostic entity with a common phenomenology and profile of objective cognitive deficits. We discuss where these commonalities arise and argue that linguistic ambiguity, shared cognitive impairments, and noncognitive factors are more likely than shared neurobiology. We suggest how future research might apply existing tools to disambiguate the phenomena that brain fog conflates.

Dialysis and cognitive impairment.

McIntyre CW, Jain A · Nature reviews. Nephrology · 2025

People with chronic kidney disease who require maintenance dialysis characteristically experience accelerated and aggravated cognitive decline compared with those with advanced kidney disease who are not receiving this form of kidney replacement therapy. This effect is inadequately appreciated, but of crucial importance to patients, their carers and the health-care systems that support them. Although many of the comorbid conditions prevalent in this patient population have the potential to affect brain structure and function, an evolving body of evidence indicates that the dialysis therapy itself has a central role in the pathophysiology of progressive cognitive impairment. Both haemodialysis and peritoneal dialysis are associated with structural and functional changes in the brain that can lead to characteristic short-term symptoms, such as headache, confusion, delirium and brain fog, as well as long-term reductions in cognitive functional ability. Here, we explore the mechanisms, bot

Long-term effects of coronavirus (long COVID)

NHS

The NHS page on long COVID discusses various symptoms, including 'brain fog,' and provides advice on managing the condition and seeking support.

The Effect of Mental Fatigue on the Cerebral Oxygenation During Endurance Exercise

n=15 · NCT05355493 · UNKNOWN · UNKNOWN

The experiment will consist of 3 consecutive trials performed in a sound-insulated climate chamber (20°C and 40% RH) at the VUB. Participants will be asked to return 3 successive weeks. Trained staff (pre-doctoral researchers and trained master students) will be present during the experimental trials. The first visit will be a familiarization trial in which they will complete all procedures as if it was an experimental trial, except for the interventional 60min Stroop task. Instead of the 60-min Stroop task the participants' maximal cognitive capacity will be determined. The participant wil come in, perform a cognitive performance test, will then perform the intervention/control procedure, which will be followed by an additional conduction of the same cognitive performance test as before the intervention/control, as well as a physical performance test (time to exhaustion cycling test). The intervention will consist of a 60 min Stroop task, while the control trial will consist of watching a documentary of the same duration. Multiple different questionnaires (e.g. to assess the mentally fatigued state of participants) will be assessed throughout the experimental/control trial. The aim of this study will be to research if mental fatigue influences prefrontal cortex oxygenation during a time to exhaustion cycling test. Marcora et al. (2009) already showed a decrease in cycling performance during the exact same protocol.

Single Arm, Monocentric, Pilot Feasibility Study on an Interactive Virtual Reality Program in 20 Complex In-clinic Palliative Care Patients

n=20 · NCT07545928 · NOT_YET_RECRUITING · NOT_YET_RECRUITING

Palliative care patients frequently face a "symptom cluster" of pain (up to 96%), fatigue (up to 90%), and anxiety (up to 79%), which severely degrades their quality of life in their final months.The study is built on the concept of passive exposure therapy (VREP), which engages multiple senses to distract the brain from pain signals. By creating an "immersive distraction" or a "flow state," VR can activate the brain's reward networks and reduce activity in areas associated with pain perception. Unlike most existing VR research in palliative care which uses "passive" VR (like watching a 360-degree video), this study uses interactive VR. Patients can perform simple actions-like grabbing or dropping virtual objects-within a calming natural environment, which may better support their sense of autonomy and dignity. Because this is a pilot study, the "Go/No-Go" decision for future larger trials depends on a strict composite of three factors: * Adherence: The patient must complete at least 11 out of 14 planned daily sessions. * Duration: Each session must average at least 7.5 minutes of usable VR exposure. * Tolerance: The patient must experience no device-related serious adverse events and maintain a high average tolerance score (VRISE score ≥ 25).

Effects of Nature Exposure Intervention on Self-Regulation and Decision-making in Mentally Fatigued University Soccer Players

n=60 · NCT04693481 · COMPLETED · COMPLETED

The current study is going to investigate the nature exposure intervention on the ability of self-regulation and decision-making skills among mentally fatigued soccer players. The subjects will be instructed to view some nature photos, which can facilitate the recovering process for directed attention and the ability of self-regulation. Thus, to see the improvement in decision-making skills.

TRIP Database

TRIP Database

The TRIP Database is a clinical search engine designed to allow users to quickly and easily find high-quality research evidence, potentially including studies related to brain fog and its causes.