Mild memory changes in your 40s may seem harmless, but in some cases, they signal the beginning of a cognitive shift that unfolds over decades. While it is much more commonly diagnosed after the age of 65, early-onset dementia can appear in midlife, often through subtle lapses in focus, recall, or decision-making.

Because these early signs resemble stress or burnout, they often go unnoticed. But when changes in thinking or behavior feel unfamiliar or persist, they deserve attention. Establishing a baseline for brain health in midlife helps detect cognitive decline if it develops. Consistent observation enables earlier intervention and more targeted support.

Normal Forgetfulness vs Dementia

The major difference between dementia and normal forgetfulness is consistency. Occasional forgetfulness is a normal part of aging. Misplacing keys, forgetting names, or losing track of time happens to almost everyone and usually doesn’t disrupt daily life. Because these lapses feel familiar, early signs of dementia often go unnoticed, mistaken for age-related changes.

But dementia follows a different pattern. The National Institute on Aging notes that memory problems become concerning when they interfere with daily routines, independence, or relationships. Cognitive decline due to dementia is gradual but persistent, characterized by repeating questions, getting lost in familiar places, or struggling to follow conversations, often without the person being aware of it. That lack of awareness can be a red flag in itself, indicating underlying neurological conditions.

These changes reflect structural brain damage seen in conditions like Alzheimer’s, Lewy body dementia, or vascular dementia, all of which cause progressive memory loss, confusion, and impaired reasoning.

How to Know If It’s Normal Forgetfulness or a Sign of Dementia

To better understand how to distinguish normal forgetfulness from a sign of dementia, here’s a side-by-side comparison of typical normal aging changes and early indicators of dementia:

Signs of Normal Aging	Early Signs of Dementia
Occasionally forgetting names, appointments, or words, but recalling them later	Frequently asking the same question or repeating the same story in a single conversation
Needing more time or effort to learn new information	Forgetting recent events or important dates entirely
Sometimes misplacing everyday items like a wallet or phone	Becoming disoriented in familiar environments
Mildly slower thinking or decision-making, but daily life remains unaffected	Difficulty managing tasks like paying bills or preparing meals
No major changes in behaviour or mood	Personality shifts, social withdrawal, or poor judgment

Reversible vs. Progressive Causes of Memory Loss

Memory loss doesn’t always signal dementia. Some causes are temporary and treatable. The chart below helps differentiate:

Reversible Causes	Progressive Causes (Dementia)
Medication side effects (e.g., antihistamines, antidepressants)	Alzheimer’s disease
Nutrient deficiencies (e.g., vitamin B12, D, E) or hormonal imbalances (e.g., thyroid)	Lewy body dementia
Depression or untreated anxiety	Vascular dementia
Sleep disorders (e.g., sleep apnea, chronic insomnia)	Frontotemporal dementia
Infections (e.g., urinary tract infection, meningitis, pneumonia)	Progressive neurodegeneration affecting memory, behaviour, and daily functioning
Dehydration or poorly managed chronic illness	Structural brain changes confirmed by cognitive decline and neuroimaging

If memory changes are noticeable, it’s important to rule out these treatable conditions before assuming a progressive disorder. A full medical evaluation helps clarify whether symptoms are reversible or part of a more persistent neurological condition.

When Testing Becomes Relevant

Not every lapse needs medical attention. However, when memory issues start interfering with appointments, conversations, or organization, formal testing becomes beneficial. Cognitive assessments help determine whether symptoms fall within the expected range of aging or reflect a more serious decline.

A great place to start is Baycrest’s Brain Health Assessment, a self-administered test developed by Cogniciti. It’s free, private and clinically researched. It takes between 20 to 30 minutes to complete, and will generate a personalized score and brain health report.

Several other screening tools are used by healthcare providers, each measuring specific parts of memory, attention, and problem-solving. Below is a comparison of the most widely used assessments and what they evaluate:

Mini-Mental State Examination (MMSE)

The MMSE is a 30-point questionnaire that assesses orientation, memory, language, attention, and basic problem-solving. It’s commonly used in clinical settings to evaluate moderate to severe cognitive impairment.

• Strengths: Widely recognized, quick to administer (about 10 minutes).
• Limitations: Less sensitive to mild cognitive impairment or early-stage dementia.
• Scoring: Scores below 24 may suggest cognitive impairment.

Montreal Cognitive Assessment (MoCA)

The MoCA is also a 30-point test but includes more complex tasks than the MMSE, making it more effective at identifying early cognitive changes and mild cognitive impairment.

• Strengths: High sensitivity to early dementia; includes executive function tasks.
• Limitations: Requires trained administration.
• Scoring: Scores below 26 may indicate cognitive decline.

Mini-Cog

The Mini-Cog combines two tasks: a three-word memory recall and a clock-drawing exercise. It’s often used in primary care as a quick screen for cognitive impairment.

• Strengths: Very brief; easy to administer.
• Limitations: Can miss subtle impairments; not diagnostic on its own.

Free and Cued Selective Reminding Test (FCSRT)

FCSRT focuses on verbal memory and the ability to recall information with and without cues. It’s beneficial for distinguishing Alzheimer’s disease from other types of dementia.

• Strengths: Helps differentiate memory disorders; reliable for early-stage detection.
• Limitations: Requires professional administration; longer duration.

Rey Auditory Verbal Learning Test (RAVLT) & California Verbal Learning Test (CVLT)

These two tests assess verbal learning, recall, and recognition through structured word lists. They are used in neuropsychological evaluations to identify early cognitive decline and study episodic memory in both clinical and research settings.

• Strengths: High sensitivity and diagnostic value.
• Limitations: Time-consuming; not used in routine screenings.

Self-Administered Gerocognitive Examination (SAGE)

SAGE is a paper-based or online test developed by Ohio State University. It evaluates memory, language, reasoning, and visuospatial skills and can be completed without the need for a health care provider.

• Strengths: Useful for early screening at home; no clinical supervision needed.
• Limitations: A less controlled environment may affect accuracy.
• Scoring: Scores under 17 may require clinical follow-up.

Can Dementia Risk Be Reduced?

Some behaviours are linked to a lower likelihood of developing dementia. Diet, physical activity, and regular social interaction all play a crucial role in maintaining long-term brain health.

Equally important is maintaining cognitive engagement. People who continue to learn new skills, take on mentally demanding tasks, or stay engaged through work or volunteering tend to exhibit slower mental decline. Activities like attending lectures, doing creative arts, and visiting museums have also been linked to better brain health. 

Though many “brain games” are marketed as tools to support brain health, the science doesn’t quite back it up. In 2016, a group of researchers reviewed the evidence for these “brain games,” and found that while users get better at the games, the improved performance doesn’t translate to other cognitive abilities. So play if you find them enjoyable, but don’t expect them to reduce your risk. 

Understanding Genetic Risk for Dementia

While lifestyle and environment shape brain health, genetics can also influence a person’s risk of developing dementia. Certain gene variants are associated with higher susceptibility, particularly in Alzheimer’s disease.

One of the most studied genetic markers is the APOE gene, which comes in three forms:

• APOE ε2 may offer some protection.
• APOE ε3 is the most common variant and is considered neutral.
• APOE ε4 is linked to a higher risk of late-onset Alzheimer’s.

Carrying the ε4 variant doesn’t mean someone will develop dementia, but it does raise lifetime risk, particularly when paired with cardiovascular issues, head injuries, or family history.

For people in their 40s or 50s with a family history of dementia, genetic counseling can offer insight. This includes reviewing medical history, discussing testing options, and considering lifestyle adjustments or cognitive screening schedules based on the results.

Knowing your genetic predisposition supports earlier cognitive monitoring and more informed decisions about health and lifestyle in midlife, when early intervention has the most impact.

How Family and Friends Can Help Identify Early Dementia

People who see a loved one occasionally, during holidays or annual visits, may be more likely to notice subtle cognitive shifts. Repeated conversations, misplaced questions, or disorientation often stand out when compared with past interactions.

In contrast, those who live with the person may normalize gradual changes. A spouse may misread forgetfulness as distraction. However, if the person forgets an entire conversation and raises the topic again as if it had never been discussed, this may indicate a deeper memory issue.

When these patterns recur, it’s advisable to consult a primary care provider. Bringing someone who has observed the changes and can describe when they began and how often they occur helps guide the evaluation.

Some changes in memory stem from medical conditions that can be managed, while others may indicate the onset of dementia. In both cases, paying attention to symptoms and seeking a professional evaluation can help clarify what’s going on and determine the best steps to take.

If you’re noticing shifts or simply want to understand your baseline, begin monitoring your cognitive health with the same care you give your physical health. 

Every conversation, every check-in, every early step matters. Explore how you can support brain health for yourself and others through our Resource Hub.