Scientists linked test results at age 13 to the risk of dementia in old age

The ability to find patterns in numbers at the age of 13 was associated with the risk of dementia more than half a century later. Scientists compared the results of school tests of Swedish residents with medical data for subsequent decades and found that the diagnosis was less common among those who performed better on one of the tasks. Whether such a test can be considered a prognosis for old age and whether training thinking will help prevent illness is in the "Izvestia" material.

How scientists looked back 60 years ago

It is not easy to check whether abilities in childhood are related to health in old age: this requires the results of old tests and the ability to trace the future lives of the same people. The authors of the study published in Alzheimer's Research & Therapy, this opportunity has appeared thanks to Swedish school and medical data.

The main analysis included 10,539 people born in 1948. In 1961, when they were about 13 years old, they were in the sixth grade and completed three assignments. The first one tested vocabulary skills: it was necessary to choose a word with the opposite meaning. The second assessed spatial thinking — the ability to imagine what a shape would look like after bending the depicted detail. In the third, the students continued the numerical series, determining the pattern. It was the latter task that the researchers used to evaluate inductive thinking — the ability to deduce a general rule from several examples.

The researchers then compared the students' results with records of hospitalizations and causes of death up to November 2025. Thus, the surveillance spanned more than six decades. During this period, dementia was recorded in 287 participants of the main group — 2.7%. This number refers to the diagnoses included in the registers used, and does not necessarily reflect all cases of the disease among the participants.

Which test was associated with the risk of dementia

A connection was found for a task with numerical series. The higher the result at age 13, the less frequently the diagnosis of "dementia" subsequently appeared in the registers. An increase in the result by one standard deviation, a measure of the differences between the group participants, corresponded to an approximately 16% lower relative risk of diagnosis during follow—up. When calculating the initial scores, each additional test point was associated with a decrease in this indicator by about 2%. These figures describe the differences between groups of people, rather than allowing you to calculate the personal risk of a particular child.

The results of tests on vocabulary skills and spatial thinking did not show an independent statistically significant association with dementia in this analysis. The authors additionally tested the conclusion on an expanded group: together with people born in 1953, it consisted of 19,919 participants. The relationship between the result of the numerical series task and the subsequent diagnosis has been preserved. At the same time, the second generation was five years younger by the end of the observation, so the researchers could not draw an equally reliable conclusion based on it alone.

Forgetfulness or Dementia: When memory problems require attention

What role did education and heart disease play?

Previous work has already linked the results of cognitive tests in youth with the risk of dementia. But by the end of adolescence, they are more noticeably influenced by their studies and the chosen educational trajectory. Therefore, the authors of the new study looked at the results obtained at the age of 13 and separately took into account the education of the parents and the participants themselves in middle age.

The relationship between the result of the numerical series assignment and dementia remained after these corrections. In this statistical model, the education received by the participants by middle age did not show an independent significant association with the diagnosis. This does not mean that studying is useless for brain health: the study assessed a specific group of people and individual indicators, rather than the consequences of abandoning education.

The researchers also tested the possible role of cardiovascular disease and diabetes. Both conditions have been associated with an increased risk of dementia. Higher numerical pattern test results, in turn, were associated with a lower incidence of these diseases. However, accounting for diagnoses only slightly weakened the main link between the school test and dementia.

This means that the reported heart disease and diabetes have not fully explained it. But it is impossible to determine from the data obtained why the connection exists: both indicators could be influenced by other features of human health or life.

Is it possible to predict the disease based on an assessment at the age of 13

The study shows a trend at the level of a large group, rather than the fate of an individual student. A lower test result does not mean that a person will develop dementia; a high result does not guarantee that the disease will not occur.

Scientists have created an atlas of microproteins to study Alzheimer's disease

The authors also point out the limitations of the method. To identify dementia, they used information about hospitalizations and causes of death. Such records might not cover cases that were observed on an outpatient basis, and usually record the diagnosis later than a special clinical examination.

By the end of the study, the participants in the main group were about 77 years old. Further observation may reveal new cases and clarify the result. Scientists also did not analyze different types of dementia separately and could not take into account all possible circumstances of childhood and adulthood. The main thing is that the study was observational: scientists did not teach one group of children to solve numerical problems in order to compare it with another.

The work gives researchers a reason to take a closer look at the early development of thinking and brain health throughout life. But it is still premature to turn the school test into a way to diagnose or promise prevention of dementia through numerical exercises.