Reviewed by the Help Dementia Editorial Team — our editors review every article for accuracy against guidance from the National Institute on Aging, the Alzheimer’s Association, and peer-reviewed sources.
Abnormal dementia screening results mean that a cognitive test has detected changes in thinking, memory, or other mental abilities that warrant further medical evaluation—but they do not automatically mean you or a loved one has dementia. When someone scores 25 or below on the Montreal Cognitive Assessment (MoCA), for example, it signals that more comprehensive testing is needed to understand what’s happening cognitively. Think of an abnormal screening result like a yellow traffic light: it tells you to proceed carefully and investigate further, not that a diagnosis is certain. Many people with abnormal screening scores live for years without developing dementia, while others may show gradual cognitive decline.
The screening test is a starting point, not an endpoint. What makes this distinction crucial is that screening tests themselves cannot confirm a dementia diagnosis. A neurologist or geriatrician must perform additional evaluations—detailed neuropsychological testing, imaging studies, and medical workup—to determine whether cognitive changes are truly due to Alzheimer’s disease, another type of dementia, normal aging, medication side effects, vitamin deficiencies, or something else entirely. False positives do occur, meaning some people will test abnormal on screening but never develop dementia. Understanding what an abnormal result actually means helps reduce unnecessary anxiety and clarifies the real next steps forward.
Table of Contents
- Understanding Cognitive Screening Score Thresholds and What They Indicate
- Why False Positives Occur and When Screening Results May Be Misleading
- Progression Rates—What Actually Happens After Abnormal Screening Results
- The Comprehensive Diagnostic Evaluation That Follows Abnormal Screening
- High-Risk Features That Predict Faster Decline
- What to Ask Your Doctor After Receiving Abnormal Screening Results
- Prevention and Monitoring While Awaiting Comprehensive Diagnosis
- Conclusion
Understanding Cognitive Screening Score Thresholds and What They Indicate
The Montreal Cognitive Assessment (MoCA) has become the standard screening tool in clinical practice because it detects cognitive problems more reliably than older tests. A normal MoCA score is 26 or higher, meaning cognitive function is within expected range. Scores between 18 and 25 typically indicate mild cognitive impairment (MCI)—a state where someone experiences noticeable cognitive decline beyond normal aging but still retains enough function to manage daily life independently. Scores below 18 raise suspicion for dementia and generally prompt urgent referral for comprehensive diagnostic testing. The distinction matters: someone scoring 22 is not the same as someone scoring 15.
Both have abnormal results, but the person scoring 22 may have MCI and stable function for years, while the person scoring 15 likely needs immediate specialist evaluation. One critical advantage of MoCA over older cognitive screening tools is its sensitivity. The Montreal Cognitive Assessment detects approximately 90 percent of mild cognitive impairment cases, whereas the Mini-Mental State Examination (MMSE)—a test used for decades—identifies only 18 to 45 percent of MCI cases. This means many people with genuine cognitive changes would be missed by the older test. Recent 2025 research comparing these instruments in genetic forms of dementia confirmed that MoCA demonstrates superior ability to distinguish between people at genetic risk but not yet showing symptoms and unaffected controls. The practical implication: if you or a family member has been screened with an older test and told results were normal, an abnormal MoCA score may still warrant serious attention.
Why False Positives Occur and When Screening Results May Be Misleading
cognitive screening tests, while useful, are imperfect tools. False-positive results do occur, meaning someone tests low on a screening but does not actually have dementia or significant cognitive impairment upon further testing. Reasons for false positives include depression (which can temporarily slow cognitive processing), anxiety, sleep deprivation, medication interactions, uncontrolled diabetes or thyroid disease, vitamin B12 deficiency, and even the stress of being tested. An older adult who had a poor night’s sleep or is anxious about doctor visits may underperform on screening. Equally important, some screening results are abnormal because of normal aging, not pathology.
The brain naturally processes information more slowly after age 70, and education level also affects scores—someone with less formal education may score lower even with normal age-appropriate cognition. This is why physicians emphasize that screening results are never diagnostic on their own. A low score creates suspicion and warrants further investigation, but it does not confirm Alzheimer’s disease, frontotemporal dementia, or any specific condition. A person screening abnormal might be experiencing mild cognitive impairment that stays stable for a decade, or they might have depression that fully reverses with treatment. The limitation of screening is that it casts a wide net—catching people who genuinely need evaluation and protecting against missed cases—but this same breadth means some people will test abnormal unnecessarily. This is why the next step after an abnormal result is always more detailed evaluation, never immediate diagnosis or treatment.
Progression Rates—What Actually Happens After Abnormal Screening Results
Once mild cognitive impairment is confirmed through more thorough testing, the natural question families ask is: How likely is this to become dementia? The answer depends on the specific type and severity of MCI, but research provides clear statistics. Among people diagnosed with mild cognitive impairment, 5.4 percent progress to dementia within one year. This rate accelerates over time: 16.1 percent progress within two years, 23.4 percent within three years, 31.1 percent within four years, and 42.5 percent within five years. This means that roughly four out of every ten people with MCI will develop dementia within five years, while six out of ten may not. Importantly, these are population averages; individual outcomes vary considerably.
Not all types of MCI carry the same risk. Multi-domain amnestic MCI—where memory loss is prominent and other cognitive areas like language or thinking speed are also affected—carries the highest risk. In this high-risk group, up to 40 percent progress to dementia within five years. In contrast, single-domain MCI (affecting only one cognitive area, like memory alone) progresses more slowly. For amnestic multiple-domain MCI specifically, annual progression rates range from 4 to 25 percent depending on the study population and severity. The takeaway: an abnormal screening result followed by an MCI diagnosis does not mean inevitable decline, but the statistical likelihood of future cognitive loss is real and should inform conversations about monitoring, preventive measures, and planning for care.
The Comprehensive Diagnostic Evaluation That Follows Abnormal Screening
After an abnormal screening result, the recommended next step is not panic but organized medical investigation. Physicians typically recommend further evaluation using more in-depth screening tools, which may include a full Montreal Cognitive Assessment if only a brief screening was administered, the Saint Louis University Mental Status Examination, or repeating the Mini-Mental State Examination in a controlled setting. However, formal diagnosis requires neuropsychological testing—a comprehensive battery of tests administered by a trained neuropsychologist that usually takes several hours to complete. These tests measure memory, attention, language, visual-spatial skills, executive function, and processing speed in far greater detail than brief screening tools.
Alongside neuropsychological testing, a diagnostic workup includes core laboratory blood tests to check for reversible causes of cognitive problems (vitamin deficiency, thyroid dysfunction, infections), a brain MRI without contrast to assess for stroke, tumor, or brain atrophy, and often referral to a neurologist or geriatric psychiatry specialist. Depending on the clinical picture, additional imaging such as CT or PET brain scans may be ordered. The advantage of this comprehensive approach is that it can identify treatable causes—someone might have cognitive symptoms from undiagnosed thyroid disease rather than dementia, or from a medication interaction that can be corrected. The trade-off is time and cost; a complete diagnostic evaluation may take weeks or longer and can be expensive. However, the investment often determines whether treatment is possible and what the actual prognosis is.
High-Risk Features That Predict Faster Decline
Certain characteristics present at the time of abnormal screening and MCI diagnosis are associated with higher likelihood of progression to Alzheimer’s disease. If cognitive decline is confirmed by a knowledgeable family member (spouse, adult child, or close caregiver who spends time with the person regularly), the risk is higher than if the cognitive change is only noted on formal testing. Similarly, if objective memory testing shows significant impairment beyond what age alone would explain, progression risk increases. The third key feature is functional change—if the person is showing declining ability to manage complex tasks like managing finances, paying bills, or driving safely, the prognosis for future decline is worse than if cognitive test scores are low but daily function remains intact. Another critical finding is abnormal verbal fluency test results.
Verbal fluency—the ability to quickly generate words in a category or starting with a specific letter—can show abnormal changes up to five years before someone meets formal criteria for dementia. An abnormal verbal fluency result on screening may therefore be an early warning sign requiring vigilant monitoring. Additionally, among people with baseline cognitive scores in the severely abnormal range, progression is much faster. Research found that combining baseline scores greater than 15.67 on the ADAS13 scale (a detailed cognitive test) with Clinical Dementia Rating scores greater than 1.5 led to an Alzheimer-type dementia rate of 12.9 percent at 12 months—meaning one in eight people with these severe baseline deficits developed dementia within a year—and 92.7 percent at 48 months (nearly all had progressed). These high-risk features help physicians and families understand whether monitoring will likely be routine or whether closer follow-up and more aggressive preventive efforts are warranted.
What to Ask Your Doctor After Receiving Abnormal Screening Results
When you or a family member receives an abnormal cognitive screening result, several specific questions deserve direct answers. First, ask whether the result represents a brief screening tool or a more comprehensive test, and whether the same test can be repeated to confirm findings. Ask the physician specifically what the score means—is this mild cognitive impairment, suspected dementia, or still within potentially normal variation? Request clarification on whether any reversible causes (medication effects, vitamin deficiency, thyroid dysfunction, depression) might explain the result. Many cognitive symptoms are reversible with proper treatment, and this possibility should be explored before assuming progressive neurodegeneration.
Ask about the next steps and timeline—what additional testing is recommended, how urgent is referral to a neurologist, and when should you schedule these appointments? Understand whether the abnormal result means the person should stop driving or making financial decisions, or whether that question requires further evaluation. Finally, ask about lifestyle factors that might slow cognitive decline, whether clinical trials might be appropriate, and how often follow-up cognitive testing should occur. A physician who cannot or will not answer these questions clearly may not be the right specialist to coordinate ongoing care. Getting specific, written answers helps families feel oriented and empowered rather than adrift.
Prevention and Monitoring While Awaiting Comprehensive Diagnosis
After abnormal screening results, there is no value in sitting passively while awaiting diagnostic testing. Research consistently shows that cardiovascular health, physical activity, cognitive engagement, sleep quality, and social connection all influence cognitive aging and may slow decline in those with early cognitive changes. Someone with an abnormal screening result should be encouraged to continue or begin regular aerobic exercise, which has mild but measurable cognitive benefits. Maintaining intellectual engagement through reading, games, volunteering, or learning new skills keeps the brain active. Addressing modifiable risk factors—controlling blood pressure and diabetes, quitting smoking, reducing alcohol use—helps prevent vascular damage to the brain.
Sleep quality deserves specific attention, as sleep deprivation actually impairs cognition acutely and chronic poor sleep is linked to dementia risk. A person waiting for comprehensive diagnostic evaluation should prioritize consistent sleep schedule, a dark and cool bedroom, and discussion with their doctor about whether sleep disorders like sleep apnea need treatment. Social engagement and meaningful relationships have repeatedly shown cognitive protective effects in research. The point is not that these lifestyle changes will reverse abnormal screening results, but that they may slow progression and improve overall quality of life while the diagnostic process unfolds. Starting these habits before diagnosis also makes them more likely to be sustained afterward.
Conclusion
Abnormal dementia screening results indicate the need for further evaluation, not a confirmed dementia diagnosis. The key is understanding what a screening tool can and cannot tell you: it can identify people at risk or with cognitive changes, but only comprehensive medical evaluation—neuropsychological testing, brain imaging, blood work, and specialist assessment—can determine whether that person actually has dementia, mild cognitive impairment, or another explanation for their cognitive changes. The statistics show that some people with abnormal screening progress to dementia within years while others remain stable for a decade or longer.
Knowing your specific risk profile based on the type and severity of cognitive changes, as well as other high-risk features, helps guide realistic expectations. Moving forward after an abnormal result means working with qualified specialists to complete a thorough diagnostic workup, asking clear questions about what the findings mean and what comes next, and beginning preventive measures that may slow cognitive decline. False positives occur, reversible causes exist, and outcomes vary widely—none of these facts make an abnormal screening result unimportant, but all of them mean the story is far from over. The abnormal result is an invitation to take cognitive health seriously and get expert evaluation, not a verdict about your future.
