JMIR Publications

ABSTRACT

Background:

Despite growing interest in Neuropsychiatric symptoms (NPS) in dementia, reliable methods for objectively and accurately monitoring these disturbances in real-world settings remain limited. This study focuses on two prominent motivational NPS: (i) apathy, defined as a reduction in goal-directed behaviour, and (ii) anhedonia, defined as a decreased ability to experience and pursue pleasure. Although conceptually distinct, these symptoms frequently co-occur in people with Alzheimer’s disease (AD) and behavioural variant of frontotemporal dementia (bvFTD), with substantial consequences for autonomy and quality of life. Validated objective and reliable markers of these symptoms are needed to improve symptom and disease monitoring and inform the development and evaluation of targeted interventions.

Objective:

To develop a framework for the remote ecological assessment of behavioural markers of apathy and anhedonia in people living with dementia. This approach will provide digital phenotypes of apathy and anhedonia useful for symptom monitoring in real-world settings.

Methods:

By capturing these digital biomarkers within participants’ natural home environments, this approach provides a novel assessment strategy to NPS. At the Institut du Cerveau in Paris, recruitment will consist of 24 patient-carer dyads with AD, 24 patient-carer dyads with bvFTD and 24 healthy control dyads. Participants will wear Empatica EmbracePlusTM smartwatches equipped with multiple physiological and motion sensors, including an accelerometer and an electrodermal activity sensor. These data will be combined with targeted behavioural questionnaires and ecological momentary assessments (EMA). Given the high-fidelity, multimodal nature of the data collected, machine learning methods will be utilised to explore profiles of apathy and anhedonia at both group and individual levels. We hypothesise that apathy and anhedonia can be reliably identified and monitored in dementia using ECOCAPTURE digital biomarkers. Specifically, we propose that markers of apathy will exhibit momentary fluctuations contingent on context and environment, whereas markers of anhedonia will show greater temporal stability across the day.

Results:

Recruitment is expected to start in late 2026 and continue through 2028. Preliminary analyses are expected from 2027, with final results anticipated in 2029.

Conclusions:

This project aims to provide novel, objective and ecologically valid behavioural indices of NPS of dementia that can be implemented in the home environment. These digital biomarkers may provide valuable information to identify windows of opportunity for intervention. Moreover, our approach may enable the therapeutic monitoring of targeted interventions aimed at supporting the autonomy of people living with dementia, alleviating carers’ stress and burden, and enabling aging in place. Clinical Trial: This protocol is registered in the French ethics committee repertory under the reference number: 26.00946.000424 - 2026-A00614-47. The protocol was approved on the 15th of July 2026 by the Comité de protection des personnes (CPP) Est II.