This study is a longitudinal cohort study using the Coronavirus Health Impact Survey (CRISIS), aiming to examine multiple predictors, including COVID-19, of mood and anxiety symptoms in adults and children. Data was collected at 3 time points: an initial assessment in April 2020 (“April”), a reassessment 3 weeks later (“May”), and a 7-month follow-up in November 2020 (“November”). Online surveys were collected in the United States and the United Kingdom by a survey recruitment service with a final sample of 859 adults and 780 children (collected via parent report).