Why brain age matters for feeling mentally tired

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Key Takeaway

Older people report less mental fatigue at first, but brains that look 'older' than expected get tired faster during thinking tasks.

What They Found

Researchers tested 85 people aged 20–84 by having them do repeated memory tasks and rate how mentally tired they felt before and after each block.People who were older by years (chronological age) tended to start the test feeling less mentally tired than younger people — their baseline fatigue was lower.A different measure, called brain age (how old a person’s brain looks compared to what’s typical), predicted how quickly people got more tired while doing the task: people with an older-looking brain got tired faster.Behavior on the task matched the self-reports: older-in-years people showed a more relaxed or ‘liberal’ response style, which lined up with their lower reported starting fatigue; this suggests behavior can reflect mental tiredness.Parts of the insula (a brain area involved in feelings and sensing the body) showed links to how fatigue and age related, hinting that the insula’s role in feeling tired may change over life.

Who Should Care and Why

People with MS and their caregivers should care because mental fatigue is a common and disruptive symptom in MS; this study shows that ‘how old your brain looks’ and your actual years of age can affect fatigue differently.If a person with MS has brain changes that make their brain look older, they might become mentally tired faster during tasks like thinking, planning, or remembering — similar to how a phone with an older battery loses charge sooner.Caregivers and therapists can use this idea by noticing that two people the same age might experience fatigue differently: one may start less tired but become exhausted quickly, while another may feel fatigue earlier but stay steady.Healthcare providers could consider both actual age and brain health when planning work, therapy, or activity schedules — for example, giving more frequent breaks to someone whose brain shows more aging.This matters for daily life: pacing, rest breaks, and task timing (doing demanding thinking tasks when freshest) can be tailored based on how a person experiences fatigue, not just their age in years.

Important Considerations

This study used a specific memory task in a laboratory setting, so results might not match every real-life situation where MS-related fatigue occurs, like during walking or social activity.Brain age was estimated from brain scans compared to typical patterns; that is a helpful clue but not a precise diagnosis of problems — think of it like a weather forecast, not a storm report.Because the study looked at people across the normal adult lifespan rather than focusing only on people with MS, we can’t assume all findings apply exactly the same way to every person with MS; individual differences and MS-related brain changes may change the picture.

Categories:

Specific Symptoms Early Research Mental Wellness

Article Topics:

AgingBrain AgeCognitive FatigueMRI

Whether you’ve recently been diagnosed with Multiple Sclerosis (MS) or are seeking to broaden your understanding of this complex, neurodegenerative disease, navigating the latest research can feel overwhelming. Studies published in respected medical journals like Journal of neurology often range from early-stage, exploratory work to advanced clinical trials. These evidence-based findings help shape new disease-modifying therapies, guide symptom management techniques, and deepen our knowledge of MS progression.

However, not all research is created equal. Some clinical research studies may have smaller sample sizes, evolving methodologies, or limitations that warrant careful interpretation. For a more comprehensive, accurate understanding, we recommend reviewing the original source material—accessible via the More Details section above—and consulting with healthcare professionals who specialize in MS care.

By presenting a wide range of MS-focused studies—spanning cutting-edge treatments, emerging therapies, and established best practices—we aim to empower patients, caregivers, and clinicians to stay informed and make well-informed decisions when managing Multiple Sclerosis.

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