Cohort Profile: COVIDMENT: COVID-19 cohorts on mental health across six nations

Key features • COVIDMENT www. covidment. is is a NordForsk-funded research collaboration across six nations, with the overarching aim to significantly advance current knowledge on mental morbidity trajectories associated with the coronavirus disease 2019 (COVID-19) in the general population and in specific risk groups. • From March 2020 through August 2021, 392 817 individuals have been recruited to the seven COVIDMENT cohorts: the Danish Blood Donor Study (N ¼ 71 562), the Estonian Biobank COVID-19 and Mental Health Data Collection cohorts (N ¼ 13 329 and N ¼ 86 116, respectively), the Icelandic COVID-19 National Resilience Cohort (N ¼ 22 849), the Norwegian BRY. DEG2020 (N ¼ 19 343), the Norwegian Mother, Father and Child Cohort Study (N ¼ 132 486), the Scottish Generation Scotland/CovidLife (N ¼ 18 518) and the Swedish Omtanke2020 (N ¼ 28 614). Semi-harmonized questionnaire data have been collected across all COVIDMENT cohorts with longitudinal data available, e. g. through linkage to the national registers. • The average age of participants ranged from 31. 8 to 58. 5 years across cohorts. The prevalence of depressive symptoms above cut-off point varied considerably across cohorts (4. 2–20. 8%). The prevalence of depressive symptoms was highest at COVID-19 incidence of 30 cases per week per 100 000 persons, i. e. 14. 3% 95% confidence interval (CI): 9. 4–21. 8%, which was 61. 0% (95% CI: 34. 0–94. 1%) higher than the prevalence at COVID-19 incidence of 0 cases per week per 100 000 persons (P ¼ 1. 1 x 10 ^ (6) ). •