Utilization of an Existing Longitudinal Observational Cohort of Community Adults to Characterize the Mental Health and Substance Use Impacts of COVID-19

The COVID-19 pandemic is causing historic disruptions worldwide. Previous epidemics have increased mental health problems and evidence of such impacts is already present in China. Thus, there is a high need to characterize the impact of COVID-19 on mental health in Canadians to "flatten the mental health curve." To address this, we propose to examine the impact of COVID-19 on mental health in an existing longitudinal observational cohort of 1502 community adults. This group has been assessed over four waves to date, three prior to COVID-19 and one during COVID-19. Leveraging these existing pre-pandemic and intra-pandemic data, we will ascertain the pandemic's effects on high-priority areas of mental health and substance use. Specifically, we propose four primary aims. The first and second are to examine the impacts on mental health symptoms (depression, anxiety, and posttraumatic stress disorder) and substance use (alcohol, cannabis, tobacco, and illicit drug use), respectively. The third aim is to examine the mechanisms by which these effects arise, including impacts of the pandemic and interrelationships among mental health and substance use. The fourth aim is to address where vulnerabilities exist by identifying high-risk and high-resilience subgroups within the larger cohort of individuals. We will also pursue two secondary aims, including sex/gender differences (separately) and targeted qualitative interviews of individuals exhibiting high-risk or high-resilience profiles. Our findings will be informed by Knowledge Users including a clinical psychiatrist, a clinical psychologist, and leaders from the Mental Health Commission of Canada, the Canadian Centre on Substance Use and Addiction, and Veterans Affairs Canada. Collectively, the research will provide a critical longitudinal perspective on the mental health impacts of COVID-19 that will provide substantive insights for government and healthcare responses in Canada and beyond.