Suicidal thoughts and behaviours (STB) are a critical public health concern, with 700 000 deaths by suicide each year. The period immediately following hospital discharge is associated with an elevated risk for suicide. Monitoring suicidal ideations throughout this period is therefore critical. However, its highly dynamic nature limits the utility of traditional risk assessments through infrequent outpatient visits. Recent advancements in ambulatory assessments and multimodal predictive approaches offer a promising new avenue. Hence, the present study aims to examine how psychological, linguistic, neurobiological and smartphone-based characteristics relate to suicidal ideation and to improve STB monitoring through a deep phenotyping approach.

In this interdisciplinary, multicentre, prospective observational study, we plan to recruit a total of 200 inpatients with current and/or past STB. The study comprises the following components: (1) a baseline assessment, conducted while participants are still in the hospital. This includes interviews, an electroencephalography recording, a video-recorded verbal task and self-report questionnaires; (2) data collection through a smartphone application during the first 4 weeks after hospital discharge with two active collection weeks of five daily ecological momentary assessments and two 1 min video diaries every other day, as well as smartphone passive sensing for 28 consecutive days and (3) two follow-up assessments, 4 weeks and 3 months after discharge. The primary outcome is self-reported suicidal ideation after hospital discharge.

The Ethics Committee of the Faculty of Arts and Social Sciences of the University of Zurich, Switzerland, approved the study for the Zurich and Basel sites (Ref: 22.09.19). Approval for the New York Site was granted by the Institutional Review Board of NYU Langone Health (i23-00366). Study findings will be disseminated via peer-reviewed, open-access publications, conference presentations, patient and public events, and dedicated social media outlets.

CRSII5_205913.