Lower Teen Mental Ability Linked to Early Stroke Risk
Author: BMJ Group
Published: 28 Jun 2024 - Updated: 8 Nov 2026
Publication Details: Peer-Reviewed | Observational Study
Table of Contents:
Synopsis - Definition - Overview - FAQs - Insights, Updates - Related Content
Synopsis
This research, a peer reviewed study published in the Journal of Epidemiology and Community Health, followed 1,741,345 Israelis who took cognitive tests at ages 16 to 20 before military service between 1987 and 2012, linking their results to the national stroke registry. After adjusting for other factors, those with low mental ability scores were more than 2.5 times as likely to have a stroke before age 50 as those with high scores, and those with medium scores were 78 percent more likely. The link was strongest for strokes caused by blood clots. The findings matter to doctors, public health planners and families because early-onset stroke can cause lasting disability, and people with lower cognitive scores may benefit from earlier support with health risks.*
At a Glance
- 1 - Between 2014 and 2018, 908 strokes were recorded among the participants.
- 2 - The average age at first stroke was 39.5, and 5 percent of stroke cases were fatal.
- 3 - Each one-unit drop in the standardized cognitive score was tied to a 33 percent higher stroke risk.
- 4 - No such link appeared for strokes caused by bleeding in the brain when the analysis used ability categories alone.
Topic Definition
- Early-Onset Stroke
Early-onset stroke is a stroke that occurs in a young adult, usually defined as before age 50. Like strokes later in life it may be ischemic, caused by a blocked blood vessel, or hemorrhagic, caused by bleeding in the brain, and it can result from traditional risk factors such as high blood pressure, diabetes, obesity and smoking as well as causes more common in the young, such as artery tears, heart defects and clotting disorders.
Overview
A lower level of mental ability during the teenage years may be linked to as much as a tripling in the risk of having a stroke before the age of 50, finds research published online in the Journal of Epidemiology & Community Health.
The observed associations held true even after factoring in current diabetes and limiting the age of a first stroke up to 40, prompting the researchers to suggest that more comprehensive assessments beyond traditional stroke risk factors are now needed to stave off disability and death.
Recent evidence suggests that cases of stroke among the under-50s are on the rise. And around half of all stroke survivors can expect to live with long term physical and psychological impairments, say the researchers.
Lower levels of mental ability in childhood and adolescence-to include powers of concentration, problem solving, and learning-have been associated with higher risks of future cardiovascular and metabolic diseases. But the findings are inconsistent, note the researchers.
To strengthen the evidence base, they wanted to find out if mental ability in adolescence might be associated with a heightened risk of early onset stroke in a nationally representative sample of 1.7 million young Israelis.
Before starting military service, 16-20 year old Israelis undergo extensive evaluation to assess their suitability, and this study includes all those assessed between 1987 and 2012.
As well as weight, blood pressure, current diabetes, other factors assessed included educational attainment, socioeconomic background, and mental ability.
This last includes tests to measure the ability to understand and carry out verbal instructions; verbal abstraction and categorization (word grouping); mathematical ability, concentration, and conceptual thinking; non-verbal abstract reasoning and visual-spatial problem solving.
The study participants' results were then linked to the Israeli national stroke database, for which mandatory reporting only began in 2014, up until the end of 2018, the first recorded stroke, or death, whichever came first.
The final analysis is based on 1,741,345 people, 738,720 (42%) of whom were women. Out of the total, 12% (312,769) were scored as having a high level of mental ability, 70% (1,220,514) as having a medium level, and 18% (208,062) as having a low level.
Compared with those whose scores indicated a high level of mental ability, those at the other end of the scale were more likely to be overweight or obese (17% vs 12%), less likely to have completed secondary school education (82% vs 99%), and more likely to have lived in a socially and economically deprived neighborhood (35% vs 19%) - all risk factors for cardiovascular disease.
Between 2014 and 2018, 908 cases of stroke were recorded, of which 767 were caused by a blood clot (ischemic) and 141 by a bleed on the brain (intracerebral hemorrhage).
The average age of a first stroke was 39.5 (maximum age 50). And 45 people died as a result (5% of all stroke cases), nearly two thirds of whom (62%) did so within 30 days of the event.
Among those scoring low to medium on mental ability, the incidence of both types of stroke was higher, particularly that of ischemic stroke.
After accounting for potentially influential factors, those with low mental ability were more than 2.5 times as likely to have a stroke before the age of 50 as those with a high level, while those with a medium level were 78% more likely to do so.
Of the 767 cases of ischemic stroke, 311 (41%) occurred before the age of 40. After accounting for potentially influential factors this risk was almost double (96% higher) among those with a medium level of mental ability and more than 3 times higher among those with a low level in their teenage years.
Heightened risk rose in tandem with the mental ability score, such that for every 1 unit decrease in the standardized (z) score, the risk rose by 33%. However, when the analysis was based on categories of mental ability alone, no such associations emerged for a stroke involving a bleed on the brain.
These associations held true even after further in-depth analyses, including factoring in current diabetes and limiting the age of first stroke up to the age of 40.
This is an observational study, and therefore can't establish cause and effect. The researchers also acknowledge various limitations to their findings, including the lack of information on lifestyle, such as smoking, physical activity, and diet; higher education; and several potentially important social determinants of health.
But they write:
"Without risk factor intervention in early adulthood, stroke risk accumulates." And they conclude: "Cognitive function may serve as a means of stratifying individuals at greater risk for stroke and for intervention via possible mediators such as health illiteracy, education, and health-related behaviors. Provision of early social and health support for individuals with lower cognitive function might be essential for mitigating their elevated risk."
More on this topic: Cognitive Disability Publications - Stroke Publications
Frequently Asked Questions
NOTE: Researched FAQs by Disabled World (DW)
What are the warning signs of a stroke?
Common signs are sudden face drooping, arm or leg weakness, slurred or confused speech, vision loss, severe headache or loss of balance. Call emergency services right away.
Can young people reduce their stroke risk?
Yes. Not smoking, staying active, keeping a healthy weight and managing blood pressure, cholesterol and diabetes all lower risk at any age.
What is the difference between ischemic and hemorrhagic stroke?
An ischemic stroke happens when a clot blocks blood flow to the brain. A hemorrhagic stroke happens when a blood vessel in or around the brain bursts.
Does lower IQ cause stroke?
No. The study shows an association, not cause. Lower scores may reflect differences in education, income and health habits that affect stroke risk.
What is health literacy?
Health literacy is the ability to find, understand and use health information to make decisions, such as following medication instructions or recognizing symptoms.
Is stroke in young adults becoming more common?
Some studies report rising rates of stroke in people under 50, possibly linked to increases in obesity, diabetes and high blood pressure in younger age groups.
What disabilities can follow a stroke?
Stroke can cause weakness or paralysis on one side, speech and language problems, memory and thinking difficulties, vision loss, fatigue and depression.
How is cognitive ability measured in large studies?
Researchers often use standardized tests of verbal reasoning, math, concentration and spatial problem solving, given to large groups under the same conditions.
Insights, Analysis, and Developments
Editorial Note: Stroke is often thought of as a disease of older age, but strokes in people under 50 can end careers and leave young families coping with long-term disability. This study suggests that lower cognitive ability in the teenage years is a marker of higher risk, probably working through factors such as education, health knowledge and access to care rather than intelligence itself. Because it is observational and lacks data on smoking, diet and exercise, it cannot prove cause, but it supports giving young adults with lower scores extra help with blood pressure, weight, smoking and other risks that can be changed.*
Attribution/Source(s): This peer-reviewed publication was selected for publishing by the editors of Disabled World (DW) due to its relevance to the disability community. Originally issued as a press release by BMJ Group and published on 28 Jun 2024. Last updated on 8 Nov 2026. This content may have been edited for style, clarity, or brevity.
* Editorial additions by Ian C. Langtree.