Mental well-being before and during the COVID-19 pandemic. Data sources: Eurofound, 2016 EQLS and 2020 LWC surveys. Lonely, tense and downhearted measure the share of respondents who, over the two weeks preceding the interview, felt more than half of the time, respectively lonely, particularly tense and downhearted/depressed. Cheerful, calm, active, rested, and interesting life are 5 indicators indicating the share of respondents who, over the two weeks preceding the interview, felt more than half of the time, respectively: cheerful and in good spirits, calm and relaxed, active and vigorous, fresh and rested, and that their daily life is filled with interesting things. These items are inputs to the world health organisation's WHO-5 mental wellbeing index.