On Blurry Boundaries When Defining Digital Biomarkers: How Much Biology Needs to Be in a Digital Biomarker?

Abstract

Recent years have seen a rise in research where so called “digital biomarkers” represent the focal study interest. Many researchers understand that digital biomarkers describe digital footprints providing insights into healthy and pathological human (neuro-)biology. Beyond that the term digital biomarker is also used at times to describe more general concepts such as linking digital footprints to human behavior (which itself can be described as the result of a biological system). Given the lack of consensus on how to define a digital biomarker, the present short mini-review provides i) an overview on various definitions and ii) distinguishes between direct (narrow) or indirect (broad) concepts of digital biomarkers. From our perspective, digital biomarkers meant as a more direct (or narrow) concept describe digital footprints being directly linked to biological variables, such as stemming from molecular genetics, epigenetics, endocrinology, immunology or brain imaging, to name a few. More indirect concepts of digital biomarkers encompass digital footprints being linked to human behavior that may act as latent variables indirectly linked to biological variables.

The future of psychopharmacology: a critical appraisal of ongoing phase 2/3 trials, and of some current trends aiming to de‐risk trial programmes of novel agents

“…More than one outcome in a trial is desirable, as one outcome only can hardly provide a comprehensive clinical picture, yet adjusting for multiple comparisons in the statistical analyses is needed in case that more than one primary outcome is be­ing assessed or in case that inferential statistical testing is desired even of key secondary outcomes. For secondary and exploratory, hypothesis‐generating outcomes and those requiring a lot of multidimensional data, such as for functioning, modern tools including digital phenotyping and ecological momentary assessment can be of great value and should be progressively introduced in assessment of trials 218‐228 . Digital phenotyping and ecological momentary assessments can be repeated mul­tiple times, and can be even continuous in case of passive monitoring.…”

Editorial: an emerging field with bright prospects

“…These include the investigation of behavioural signatures of personality, as seen, for example, with 'digital phenotyping' that applies methods from psychoinformatics that when combined with neuroscientific data allows the emergence of psychoneuroinformaticsthis is especially relevant because it is ecologically valid (e.g., call behaviour on smartphones as a putative marker of sociality/extraversion; . Surprisingly, this is seldom done in the neurosciences at this time, despite the tendency of neuroscience researchers to be early adopters of new technologies (Montag, Elhai, & Dagum, 2021b). In addition to the accessibility of intensive ecological sampling, virtual reality is opening up further intriguing possibilities, especially in the experimental manipulation of environmental/situational variables (e.g., Krupic, Zuro, & Corr, 2021).…”

“…Molecular (genetic) studies clearly fall within the realm of personality neuroscience (Montag, Ebstein, Jawinski, & Markett, 2020) and this, too, could benefit from digital phenotyping (Montag, Dagum, Hall, & Elhai, 2022). For example, whether it is possible to carve out digital biomarkers (Montag, Dagum, Hall, & Elhai, 2021); and it would be interesting to see if we find patterns of digital footprints (Montag, Elhai, & Dagum, 2021b) giving insights into both the neurobiology and personality of the person.…”

Digital Biomarkers in Psychiatric Research: Data Protection Qualifications in a Complex Ecosystem

“…Digital biomarkers, i.e., “consumer-generated physiological and behavioral measures collected through connected digital tools” ( 11 ) or “objective, quantifiable, physiological, and behavioral measures collected by means of digital devices that are portable, wearable, implantable, or digestible” ( 12 ), arguably have the potential of addressing at least some of the traditional biomarkers' limitations ( 13 , 14 ). Improvements in sensors, software, and algorithms, together with the increasingly widespread adoption of digital technologies in daily life, enable the gathering of key health-related data remotely, in non-invasive and seamless ways, blurring the boundaries between biomedical research and research participants' daily life ( 15 , 16 ).…”