Study Shows an Increasing Trend of Brain Fog Among Adults
Analysis of over 4.5 million U.S. survey responses spanning a decade
(2013–2023) shows a rise from 5.3% to 7.4% in reported cognitive
disability nationwide, with an exceptional surge in the 18–39 age group
and a clear influence of income and education.
A new study indicates that self-reported problems with memory, concentration, and decision-making are occurring with increasing frequency, particularly among young adults in the United States, with socioeconomic factors playing a central role in the phenomenon. The findings were published in Neurology, the journal of the American Academy of Neurology.
"Difficulties in memory and thinking have become one of the most
commonly reported health issues among adults in the U.S.," says study
author Adam de Havenon, M.D., M.S., from the Yale School of Medicine in
New Haven, Connecticut, and a Fellow of the American Academy of
Neurology. "Our research shows that the phenomenon is expanding,
especially among younger adults, and that social and structural factors
likely play a key role."
A Decade of Data from the BRFSS
To reach their conclusions, the researchers analyzed more than 4.5
million responses to annual surveys collected through the CDC’s
Behavioral Risk Factor Surveillance System (BRFSS) between 2013 and
2023. Respondents were asked the key question: "Due to a physical,
mental, or emotional condition, do you have serious difficulty
concentrating, remembering, or making decisions?" Those who answered
"Yes" were classified as having a cognitive disability.
The analysis specifically excluded data from people who reported depression, and the year 2020 was omitted to account for the unique stresses of the early COVID-19 pandemic. The data showed that the significant uptick in self-reported cognitive issues began around 2016.
During the decade, the overall prevalence of self-reported cognitive disability in the US rose from 5.3% in 2013 to 7.4% in 2023.
The sharpest jump, however, occurred among young adults:
* In the under-40 age group (18–39), the rate nearly doubled—from 5.1% in 2013 to 9.7% in 2023. This age group was the primary driver of the overall national rise.
* In contrast, a slight decrease was recorded among older adults: in the
70-and-over age group, prevalence dropped from 7.3% to 6.6%.
Structural Disparities Highlighted
Although this study relies on self-reported data rather than a clinical diagnosis, the research reveals profound socioeconomic disparities in the trend.
The researchers found that adults with a household income of less than $35,000 per year consistently reported the highest rates, which increased from 8.8% to 12.6% over the study period. For comparison, among those with an income greater than $75,000, the rates rose only from 1.8% to 3.9%.
Patterns by Race and Ethnicity
Despite White individuals constituting the majority of respondents, the
increase in cognitive disability was recorded across nearly all racial
and ethnic groups:
American Indian/Alaska Native: 7.5% - 11.2% (Highest Prevalence)
Hispanic 6.8% - 9.9%
Black 7.3% 8.2%
White 4.5% 6.3%
Asian 3.9% 4.8% (Lowest Prevalence)
"The findings indicate that the steepest increases are occurring among
people who are already facing structural disadvantages," Dr. de Havenon
states. "We need to better understand and address the underlying
socio-economic factors that may be driving this trend."
What is Driving the Surge?
More research is needed to pinpoint the exact cause behind this significant surge among younger adults, given the potential long-term consequences for health, workforce productivity, and healthcare systems.
Study co-author Ka-Ho Wong, a population health scientist at the University of Utah, has suggested that one factor could be the increased mental burden stemming from changing economic conditions. "Economic stressors, like job market uncertainty and changes in work environments, could be a huge factor," Wong noted in related discussions about the findings.
Dr. de Havenon adds that the increase could reflect an actual change in brain health, greater public awareness and willingness to report these issues, or other health and social factors. "Either way," he concludes, "the rise is real, and it is especially pronounced in the under-40 age group."
The study acknowledges its limitations, including the reliance on
telephone surveys—which can be subject to respondents' memory
inaccuracies—and a broad, self-reported definition of "disability."