Smartphone tests spot cognitive decline faster than standard method

People with “mild cognitive impairment” (MCI) are at higher risk of developing dementia. Indeed, many of them experience a gradual decrease in cognitive performance over time. Smartphone- or tablet-based memory tests can capture this subtle decline more quickly than conventional testing. These findings come from a study by DZNE in collaboration with university hospitals in Germany, the University of Wisconsin–Madison in the United States, and the German start-up “neotiv”. In the researchers’ view, digital tests like these could help accelerate clinical trials for new dementia drugs, particularly regarding Alzheimer’s disease. Over the longer term, they also see potential for use in clinical routine. The results were published in the scientific journal “npj Digital Medicine” and are based on data from about 200 older adults.

“Conventional methods for assessing cognitive performance are based on standardized tasks that must be completed orally or in writing – and importantly, under supervision,” explains Dr. David Berron, who leads a research group at DZNE’s Magdeburg site. Berron is also a co-founder of the company “neotiv,” whose app was used in the current study. “By contrast, the current study involved self-administered at-home memory tests using the neotivTrials app, which allow us to collect what are known as digital biomarkers. The results show that this approach can also provide information about how cognitive performance changes over time. This subtle cognitive decline can even be detected within shorter periods of time, as measurements can be performed more frequently than with conventional methodology. While we did use a particular app, in my view these results have broader implications: They provide the first evidence that cognitive decline can be assessed using remote digital tools.”

The current study included a total of 202 women and men from Germany and the United States. Participants ranged in age from 52 to 85 years; 50 of them had MCI. People with this condition are generally still able to manage well in everyday life. However, their cognitive performance is measurably impaired.

Testing at home

Prior studies have already established that this particular mobile app, whose testing principle is based on DZNE research, can identify MCI. The current study now shows that this self-administered testing is also sensitive enough to track subtle changes in cognitive performance over time. “From a medical perspective, what matters is not only whether MCI is present, but also whether the symptoms remain stable or worsen,” Berron explains.

According to Dr. Sarah Polk, first author of the current publication and a colleague of David Berron, the app’s mobile approach has key advantages: “Testing can be done at home, at your own pace. All you need is a smartphone or tablet – there’s no need to visit a study center or make an appointment. This makes it easy to repeat the test at short intervals with little effort.”

High-frequency monitoring

In this way, changes in cognitive performance can be tracked more closely than with conventional methods, allowing effects to be detected within a relatively short period of time, Polk explains: “With the conventional approach, the considerable effort involved means that testing is realistically possible only once or twice a year. In contrast, our participants used the app for around seven to twelve months and tested themselves with it about every two weeks. During this period, we were already able to observe a decline in cognitive performance among people with MCI.”

The reliability of such results is not a given – a new method first has to show that it truly measures what it is meant to measure. This requires a suitable benchmark: In the current study, long-term clinical data were available for every participant, gathered over an average of eight years using established procedures. The long-term trajectory derived from these data was consistent with the app-based results obtained over only a few months – providing evidence for the digital measurement’s validity. “What I found particularly impressive was that, with just a few months of app use, we were able to capture a signal that aligns with years of clinical observations. That gives us confidence that this method really measures what it is supposed to measure,” Polk adds.

Shorter therapy studies, individual monitoring

“Therapy development is an obvious area of application for our digital approach – in other words, evaluating new medications for dementia,” Berron says. In this context, the goal is to determine whether and how well an experimental drug can slow mental decline – ideally already at the stage of MCI, which is considered a potential precursor to dementia. “A digital approach could help speed up clinical trials, because it could make it possible to determine whether the drug being tested has the desired effect more quickly than with conventional methods.” Looking ahead, once a larger body of data is available, this approach could be applied not only in research but also in routine clinical care, Berron surmises. “In my view, there are two practical use cases: firstly, assessing whether cognitive abilities are developing in an age-appropriate way; and secondly, monitoring an ongoing treatment to determine whether it is having the desired effect, and to what extent. Essentially, digital assessment can facilitate individual patient monitoring.”

Stages of the disease

Alzheimer’s disease, the most common form of dementia, spreads gradually, progressively damaging more and more areas of the brain. The app accounts for this phenomenon: its four subtasks, which involve memorizing images of objects and rooms or identifying differences between images, target different memory functions and therefore different brain regions. Among the participants with MCI, performance on two of these tasks was already severely impaired at the start of the study and no further decline could be measured. “This suggests that the associated brain regions had already been damaged to such an extent that they had reached the lower limit of their functional capacity,” Berron says. In the other two tasks, however, a gradual decline in performance over time could be measured as disease progressed.

Even before MCI?

App-based tests, or subtasks, that no longer detect changes in individuals with MCI, may nevertheless be important in even earlier disease stages, Berron suspects. “In the earliest disease stage, subtle cognitive impairment may already be present that we simply cannot measure using conventional tests. We now aim to take a closer look at whether the digital approach might help in this regard.”

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Background - neotivTrials app: The app used in the present study was developed by neotiv GmbH. The Magdeburg-based start-up, a spin-off from Otto von Guericke University Magdeburg, is a long-standing cooperation partner of DZNE. The app is based on DZNE research findings on how Alzheimer’s disease – the most common form of dementia – affects different regions of the brain. Alongside the version used in this study, which is tailored specifically to clinical trials (neotivTrials), another version is available that is certified as a medical device (neotivCare). Specialist medical practices may use it as an aid in diagnosing cognitive disorders. Both versions of the app are applied solely under scientific or medical supervision. The results of the memory tests are evaluated by the relevant study center or medical practice. Accordingly, the app itself does not inform users about their test results or cognitive performance. Assessment of the test data is carried out exclusively by qualified medical personnel.

Transparency note: Dr. David Berron is a scientist at DZNE as well as co-founder and Chief Science Officer of neotiv GmbH, whose app was used in the current study. The related publication in the scientific journal “npj Digital Medicine” was reviewed by independent experts through an established peer-review process.

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About Deutsches Zentrum für Neurodegenerative Erkrankungen, DZNE (German Center for Neurodegenerative Diseases):

DZNE is among the world’s leading research centers dedicated to neurodegenerative diseases, including Alzheimer’s, Parkinson’s, and ALS. These conditions are linked to dementia, movement disorders, and other severe health impairments. They place an enormous burden on patients and their families, as well as on society and the health care system. DZNE plays a key role in developing novel strategies for prevention, diagnosis, care, and treatment – and in bringing them into practice. With ten sites across Germany, it collaborates closely with universities, university hospitals, and other research institutions both in Germany and internationally. DZNE is publicly funded and is a member of the Helmholtz Association and the German Centers for Health Research. www.dzne.de/en