Fig. 1

Study timeline. The study involves a baseline characterization phase, an ecological momentary intervention phase, and a follow-up phase. On-site assessments are done at the beginning of the baseline and follow-up phases. In Berlin, Tel Aviv, and Warsaw, all baseline on-site assessments are conducted on one day, while in Mainz and Nijmegen, these baseline assessments are split into two days: M.I.N.I. interview and blood sampling are done on day 1, all remaining procedures are performed on day 2. On both testing days in Mainz and Nijmegen, a urine drug test is conducted. On-site assessments are complemented by regular online monitoring of stressors, mental health problems, and selected resilience factors. Abbreviations: EMA, ecological momentary assessment; EMI, ecological momentary intervention; EPA, ecological physiological assessment; JITAI EMI, just-in-time ecological momentary intervention; M.I.N.I., Mini-International Neuropsychiatric Interview