A Digital System to Assess Mental Health in People With Intellectual Disability (MENTALSED): Protocol for a Development and Pilot Study.

Background: People with intellectual disabilities have a high prevalence of mental health problems, which are often underdiagnosed and treated late due to difficulties in assessment. The limited availability of validated instruments, communication barriers, and reliance on external informants hinder the early detection of symptoms and the monitoring of their progression. Objective: This study describes the protocol for the development and piloting of MENTALSED, a digital assessment system designed for the continuous monitoring of mental health and emotional well-being in people with intellectual disability through ecological momentary assessment using traditional questionnaires supplemented with psychophysiological measures. Methods: The study uses a mixed methods design, combining quantitative and qualitative procedures. Following a literature review, a survey assessed the needs of direct care professionals. On the basis of these findings, self-report and proxy-report EMA questionnaires were developed. The professional version was evaluated by university experts and direct care professionals. The self-report version was adapted into an easy-to-read format with the support of a focus group of people with intellectual disabilities and subsequently evaluated by individuals with intellectual disabilities and professionals. The questionnaires were implemented on the Avicenna Research platform. Objective psychophysiological measures (heart rate variability via a chest strap and sleep quality and heart rate via a smartwatch) were included. All data are integrated into a custom application displaying 4 well-being dimensions. The subsequent pilot study will involve individuals with intellectual disability and support professionals over a 2-week period in natural settings. Results: The project was funded by the Ministry of Science, Innovation and Universities, the State Research Agency, and the European Regional Development Fund/European Union (grant PID2023-150190OA-I00/MENTAL-SED). The needs assessment and validation phases were conducted between January and May 2025. As of manuscript submission, a total of 91 participants (71 professionals and experts and 20 individuals with intellectual disability) have been recruited and have participated in the development and validation stages. The 2-week pilot study is currently concluding data collection. Data analysis for the pilot phase is expected to begin in October 2026, and the final results are expected to be published in 2027. Conclusions: MENTALSED is expected to facilitate the early detection of emotional and behavioral changes, improve diagnostic accuracy, and enable the development of evidence-based preventive interventions. The integration of multiple sources of information is expected to help overcome traditional limitations in mental health assessment in this population.