Students are at elevated risk for mental health problems. The COVID-19 pandemic and public health responses such as school and university closures caused once-in-a-lifetime disruptions of daily life for most students. In March 2020, during the beginning of the outbreak in the Netherlands, we used Ecological Momentary Assessment to follow 80 bachelor students 4 times a day for 2 weeks. Despite rapidly increasing rates of infections and deaths, short-term dynamics revealed slight decreases of mental health problems, COVID-19 related concerns, and loneliness, especially in the first few days of the study. Students showed no changes in the frequency of in-person social activities. Dynamic network models indicated that social activities were negatively related to being at home, and identified reinforcing vicious cycles among mental health problems and being alone, which in turn predicted concerns about COVID-19. Findings and implications are discussed in detail.

For many students, the COVID-19 pandemic caused once-in-a-lifetime disruptions of daily life. In March 2020, during the beginning of the outbreak in the Netherlands, we used ecological momentary assessment to follow 80 undergraduate students four times per day for 14 days to assess mental health, social contact, and COVID-19-related variables. Despite rapidly increasing rates of infections and deaths, we observed decreases in anxiety, loneliness, and COVID-19-related concerns, especially in the first few days. Other mental health variables, such as stress levels, remained stable, whereas depressive symptoms increased. Despite social-distancing measures implemented by the Dutch government halfway through our study, students showed no changes in the frequency of in-person social activities. Dynamic network models identified potential vicious cycles between mental health variables and being alone, which predicted concerns about COVID-19 and was followed by further mental health problems. Findings and implications are discussed in detail.