Measures and definitions
The questionnaire of the LockUwell survey was constructed through an iterative testing process that included revisions by epidemiologists, psychiatrists in several subspecialties, mental-health service users, and citizens, as described elsewhere.19 The survey included sociodemographic data (section 1), an evaluation of well-being (validated French version of the Warwick-Edinburgh Mental Well-Being Scale, WEMWBS) (section 2), stress evaluations (section 3), medical, psychiatric, lockdown and isolation, and social contact history (section 4), personal situation (infection or exposure of self or family, friends, and co-workers) regarding Covid-19 (section 5), as well as personal and environmental conditions during lockdown including watching news, physical exercise and sports activities, and sleep disorders (section 6).20,21 The items were not randomised. Respondents were able to review and change their answers through aback button. The estimated duration of the questionnaire was 15 to 30 minutes.