BELHEALTH: a longitudinal study to monitor the mental health of the Belgian population postpandemic

Abstract Between April 2020 and June 2022, the Belgian Health Institute (Sciensano) launched 11 online “COVID-19 Health Surveys” to assess the impact of COVID-19 and the subsequent policy responses on people's attitudes, behaviors and overall physical, mental and social well-being. Results showed an increase in the prevalence of anxiety and depression when policy measures became stricter to contain the rise of COVID-19 infections and deaths. Due to the substantial impact the crisis had on mental health, it is crucial to continue the monitoring efforts in the aftermath of the COVID period. In order to track changes over time and explore potential predictors and risk factors, the study design of the COVID-19 Health Surveys shifted to a longitudinal cohort approach (BELHEALTH). Among the 50,000 participants in the COVID-19 Health Surveys, a total of 12,000 individuals agreed to be part of the BELHEALTH cohort and participate in the online surveys every three months. Results of the BELHEALTH cohort (October 2022 and February 2023) show that the percentage of adults experiencing anxiety and depression are significantly lower compared with the percentages during high restriction periods, but remain high compared to the percentages during pre-pandemic times (Health Interview Survey 2018). Several other mental health indicators are monitored, such as subjective mental health, life satisfaction, sleep quality, concerns regarding current societal challenges, etc. The mental health indicators from the COVID-19 Health Surveys and the BELHEALTH cohort, together with mental health indicators from other sources, are communicated on the epidemiological dashboard of the institute.