Chicago, January 28, 2026 — Patients in the U.S. experiencing long COVID report significantly higher rates of brain fog, depression, and other cognitive issues than those in countries like India and Nigeria, according to a new international study. The disparity isn’t necessarily about *more* severe illness, but rather *how* illness is perceived and discussed.
The study, the first of its kind to compare long COVID neurological symptoms across continents, suggests cultural factors play a major role in how—and how often—people report these debilitating conditions.
- Around 86% of non-hospitalized U.S. patients reported brain fog, compared to 15% in India.
- Nearly 75% of non-hospitalized U.S. patients experienced symptoms of depression or anxiety, versus less than 20% in Nigeria and India.
- Cultural stigma surrounding mental health may contribute to underreporting in some countries.
- The study tracked over 3,100 adults with long COVID across four countries.
What explains the difference in reported long COVID symptoms? The study suggests that in the U.S. and Colombia, openly discussing mental health and cognitive difficulties is more culturally accepted than in Nigeria and India. This difference in openness, rather than a difference in the severity of the disease itself, may be driving the higher reported rates of symptoms.
Cultural Barriers to Reporting
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The research, which tracked more than 3,100 adults with long COVID evaluated at academic medical centers in Chicago; Medellín, Colombia; Lagos, Nigeria; and Jaipur, India, revealed striking differences. Among those who weren’t hospitalized during their initial COVID infections—the majority of participants—86% in the U.S. reported brain fog, compared to 63% in Nigeria, 62% in Colombia, and just 15% in India. Psychological distress followed a similar pattern: nearly 75% of non-hospitalized U.S. patients reported symptoms of depression or anxiety, while only 40% in Colombia and fewer than 20% in Nigeria and India did.
“It is culturally accepted in the U.S. and Colombia to talk about mental health and cognitive issues, whereas that is not the case in Nigeria and India,” explained Dr. Igor Koralnik, senior study author and chief of neuro-infectious disease and global neurology at Northwestern University Feinberg School of Medicine. “Cultural denial of mood disorder symptoms as well as a combination of stigma, misperceptions, religiosity and belief systems, and lack of health literacy may contribute to biased reporting. This may be compounded by a dearth of mental health providers and perceived treatment options in those countries.”
Beyond Brain Fog: Common Long COVID Symptoms
While brain fog and psychological distress showed the most significant disparities, other neurological symptoms were common across all countries. These included fatigue, muscle pain (myalgia), headache, dizziness, and sensory disturbances like numbness or tingling. Insomnia was particularly prevalent among non-hospitalized U.S. patients, reported by nearly 60%, compared to roughly one-third or fewer in Colombia, Nigeria, and India.
Statistical analysis revealed a clear separation between high- and upper-middle-income countries (U.S., Colombia) and lower-middle-income countries (Nigeria, India), suggesting socioeconomic factors also play a role in symptom reporting.
Understanding the Long-Term Impact of COVID
Long COVID, affecting millions globally, is characterized by symptoms that persist for weeks or even years after the initial infection. Various studies estimate that 10-30% of adults infected with COVID develop long-term symptoms, with neurological and cognitive complaints being among the most common and disabling. The authors emphasize that long COVID “affects young and middle-aged adults in their prime, causing significant detrimental impact on the workforce, productivity and innovation all over the world.”
In this study, U.S. patients consistently reported the highest burden of neurological and psychological symptoms, which, according to Koralnik, “affected their quality of life and ability to work.”
Looking Ahead: Culturally Sensitive Care
The study’s authors stress the need for culturally sensitive screening tools and diagnostic approaches for long COVID. Healthcare systems must also be equipped to provide long-term follow-up and treatment. Building on this research, Koralnik and his collaborators are now investigating cognitive rehabilitation treatments for long COVID brain fog in Colombia and Nigeria, utilizing protocols developed at the Shirley Ryan AbilityLab in Chicago.
What are your experiences with long COVID? Share your thoughts in the comments below.
