Forgetting an appointment, rereading the same message several times or struggling to concentrate on a work email: these daily difficulties do not only concern seniors. In the United States, a large survey of more than 4.5 million adults reveals an increase in self-reported cognitive disorders between 2013 and 2023. Young adults are particularly affected by this increase.
Published in 2025 in the scientific journal Neurologythe analysis by researcher Ka-Ho Wong, based on data from an American public health survey, shows that the proportion of 18-39 year olds reporting a cognitive disability increased from 5.1% to 9.7%. Among people aged 70 and over, it decreased slightly, from 7.3% to 6.6%.
Memory problems in people under 40: what do the figures show?
Between 2013 and 2023, the proportion of U.S. adults reporting difficulty with memory, concentration or decision-making increased from 5.3% to 7.4%, according to the U.S. Centers for Disease Control and Prevention (CDC). These numbers come from the Behavioral Risk Factor Surveillance System (BRFSS), a large-scale telephone survey.
However, be careful with their interpretation: the difficulties are declared by the participants themselves. They do not necessarily correspond to a medical diagnosis of cognitive disorder.
The questionnaire seeks to find out in particular if the respondents have significant difficulty concentrating, remembering certain things or making decisions due to a physical, mental or emotional problem. In Ka-Ho Wong’s analysis, people who reported diagnosed depression were excluded in order to more precisely study other factors likely to be associated with these difficulties in those under 40.
These results therefore invite us to take a closer look at the cognitive health of young adults, without assimilating each forgetfulness to a medical problem.
Stress, insecurity, screens: why are young adults affected?
Living conditions seem to play an important role. According to the figures from the study relayed by the magazine Science et Vie, 12.7% of adults under 40 earning less than $35,000 per year, or around 30,000 euros, declared a cognitive disability in 2023. This proportion also reached 12.7% among people without a secondary school diploma, compared to 3.6% among those with higher education.
Several factors could contribute to these differences. Financial stress, professional insecurity and difficulty planning for the future can weigh on sleep, attention and memory. These difficulties can also be combined with professional and family constraints.
The digital environment is also mentioned among the avenues to explore. Repeated requests, notifications and constantly switching from one task to another can make it difficult to concentrate. Vascular neurologist Adam de Havenon, from Yale University, is particularly interested in the cognitive performance of adults and the factors likely to influence them.
However, it remains difficult to attribute this increase to a single cause. The survey data describes an evolution of declared difficulties, but does not allow, on its own, to determine the respective share of stress, socio-economic conditions or digital habits.
Cognitive health: why should we take these difficulties seriously?
When they become frequent, memory and concentration difficulties can have concrete consequences: errors at work, more difficult learning, forgotten appointments or complicated administrative procedures. They can also make it more difficult to follow treatment or manage your daily health.
However, occasional forgetfulness does not mean that we suffer from a cognitive disorder. Fatigue, lack of sleep, stress or a particularly busy period can temporarily affect attention and memory skills.
If these difficulties persist, worsen or disrupt daily life, it is better to talk to a doctor. A consultation will help look for possible causes and determine if tests are necessary.
The results of this study above all highlight the interest in better monitoring cognitive health at all ages. For researchers, the challenge is to better understand this progression and to identify the factors on which it would be possible to act, in particular through prevention and better consideration of living conditions.