Cognitive impairment is one of the most commonly reported features of post-acute sequelae of COVID-19 (PASC), yet the long-term cognitive trajectories of individuals who were hospitalized with the virus have remained poorly understood. Most prior research captured a single point in time or followed patients for only a few months. This study set out to change that by tracking cognitive outcomes over a full 36 months using BrainCheck as the digital assessment platform. It represents one of the largest and longest-running evaluations of cognitive outcomes following COVID-19 hospitalization to date.
Research Objective
The goal of the study was to determine long-term cognitive changes in a cohort of individuals hospitalized with COVID-19, characterize their distinct cognitive trajectories over 36 months, and identify factors associated with each trajectory. Researchers were not just asking whether cognitive impairment occurred—they were asking how it evolved over time, and for whom.
Study Design and Methods
This was a longitudinal observational cohort study conducted at UTHealth Houston. Participants were 630 patients who had been hospitalized for severe COVID-19 symptoms and were assessed repeatedly over a 36-month follow-up period. BrainCheck served as the digital cognitive assessment platform, looking at various cognitive domains, including attention, cognitive flexibility, processing speed, and memory. Using BrainCheck for the study enabled repeatable, scalable evaluation across time points.
Key Findings
The study identified four distinct cognitive trajectories among participants over the 36-month period:
- Group 1 (48%, N=103): Consistent normal cognitive function throughout the study period.
- Group 2 (7%, N=14): Transitioned from unimpaired to impaired—representing a pattern of delayed cognitive decline.
- Group 3 (14%, N=29): Improved from impaired to unimpaired over time, suggesting meaningful cognitive recovery in a subset of patients.
- Group 4 (32%, N=68): Showed persistent impairment across all cognitive domains throughout the full 36 months.
A notable and clinically significant finding was the identification of the delayed decline group (Group 2). This subset of patients appeared cognitively intact in early follow-up but showed impairment at later time points—a pattern the researchers suggest may reflect ongoing PASC-associated mechanisms, potentially including chronic cerebral inflammation, continuing to affect the brain well after the acute infection resolves.
The study also found that poorer cognitive outcomes were associated with Hispanic ethnicity, though the effects varied across cognitive domains.
Why These Findings Matter
This study reinforces a critical point that cognitive impairment following COVID-19 hospitalization is not a single, uniform experience. For many patients, it is not static, and it can recover, persist, or, in some cases, emerge later. That variability makes longitudinal monitoring essential, not optional.
For BrainCheck, this study demonstrates the platform’s ability to track meaningful cognitive change across multi-year time horizons in real-world populations. It highlights the value of remote, repeatable assessment at scale and not just as a one-time screening tool, but as a continuous monitoring platform suited for chronic condition management and longitudinal care models.
The finding that some patients experience a delayed onset of cognitive decline is particularly important from a clinical standpoint. It suggests that a normal cognitive assessment shortly after hospitalization does not rule out future impairment, and that ongoing monitoring may be necessary to catch cognitive changes before they become clinically apparent.
Citation
Maziero MP, Lee EA, Colpo GD, Couture L, Merrill LC, Baskin L, Cahuiche AE, Petway A, Fan H, Reese E, Anderson KM, McCullough LD, Schulz PE, Ortiz GJ IV. Cognitive Trajectories After Hospitalization for COVID-19: A 36-Month Longitudinal Study. The Journal of Neuropsychiatry and Clinical Neurosciences. Published online April 7, 2026. PubMed: 41943185. doi:10.1176/appi.neuropsych.20250267.
Access the full publication here: https://psychiatryonline.org/doi/10.1176/appi.neuropsych.20250267
Written by Mary Patterson, M.S.
VP of Clinical Operations at BrainCheck
Mary Patterson is a clinical and operational leader with more than a decade of experience advancing medical technologies through clinical research and regulatory strategy. Her expertise spans neuroscience, Alzheimer’s disease, and neurovascular research, with a focus on translating evidence-based science into regulated, real-world medical products.
